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Arctic seabed methane stores destabilising, venting

2010-03-07T03:15:00.003+05:30

A section of the Arctic Ocean seafloor that holds vast stores of frozen methane is showing signs of instability and widespread venting of the powerful greenhouse gas, according to the findings of an international research team led by University of Alaska Fairbanks scientists Natalia Shakhova and Igor Semiletov.

The research results, published in the March 5 edition of the journal Science, show that the permafrost under the East Siberian Arctic Shelf, long thought to be an impermeable barrier sealing in methane, is perforated and is leaking large amounts of methane into the atmosphere. Release of even a fraction of the methane stored in the shelf could trigger abrupt climate warming.

“The amount of methane currently coming out of the East Siberian Arctic Shelf is comparable to the amount coming out of the entire world’s oceans,” said Shakhova, a researcher at UAF’s International Arctic Research Center. “Subsea permafrost is losing its ability to be an impermeable cap.”

Methane is a greenhouse gas more than 30 times more potent than carbon dioxide. It is released from previously frozen soils in two ways. When the organic material—which contains carbon—stored in permafrost thaws, it begins to decompose and, under oxygen-free conditions, gradually release methane. Methane can also be stored in the seabed as methane gas or methane hydrates and then released as subsea permafrost thaws. These releases can be larger and more abrupt than those that result from decomposition.

The East Siberian Arctic Shelf is a methane-rich area that encompasses more than 2 million square kilometers of seafloor in the Arctic Ocean. It is more than three times as large as the nearby Siberian wetlands, which have been considered the primary Northern Hemisphere source of atmospheric methane. Shakhova’s research results show that the East Siberian Arctic Shelf is already a significant methane source: 7 teragrams yearly, which is equal to the amount of methane emitted from the rest of the ocean. A teragram is equal to about 1.1 million tons.

“Our concern is that the subsea permafrost has been showing signs of destabilization already,” she said. “If it further destabilizes, the methane emissions may not be teragrams, it would be significantly larger.”

Shakhova notes that Earth’s geological record indicates that atmospheric methane concentrations have varied between about .3 to .4 parts per million during cold periods to .6 to .7 parts per million during warm periods. Current average methane concentrations in the Arctic average about 1.85 parts per million, the highest in 400,000 years, she said. Concentrations above the East Siberian Arctic Shelf are even higher.

The East Siberian Arctic Shelf is a relative frontier in methane studies. The shelf is shallow, 50 meters or less in depth, which means it has been alternately submerged or terrestrial, depending on sea levels throughout Earth’s history. During Earth’s coldest periods, it is a frozen arctic coastal plain, and does not release methane. As the planet warms and sea levels rise, it is inundated with seawater, which is 12-15 degrees warmer than the average air temperature.

“It was thought that seawater kept the East Siberian Arctic Shelf permafrost frozen,” Shakhova said. “Nobody considered this huge area.”

Earlier studies in Siberia focused on methane escaping from thawing terrestrial permafrost. Semiletov’s work during the 1990s showed, among other things, that the amount of methane being emitted from terrestrial sources decreased at higher latitudes. But those studies stopped at the coast. Starting in the fall of 2003, Shakhova, Semiletov and the rest of their team took the studies offshore. From 2003 through 2008, they took annual research cruises throughout the shelf and sampled seawater at various depths and the air 10 meters above the ocean. In September 2006, they flew a helicopter over the same area, taking air samples at up to 2,000 meters in the atmosphere. In April 2007, they conducted a winter expedition on the sea ice.

They found that more than 80 percent of the deep water and greater than half of surface water had methane levels more than eight times that of normal seawater. In some areas, the saturation levels reached at least 250 times that of background levels in the summer and 1,400 times higher in the winter.

They found corresponding results in the air directly above the ocean surface. Methane levels were elevated overall and the seascape was dotted with more than 100 hotspots. This, combined with winter expedition results that found methane gas trapped under and in the sea ice, showed the team that the methane was not only being dissolved in the water, it was bubbling out into the atmosphere.

These findings were further confirmed when Shakhova and her colleagues sampled methane levels at higher elevations. Methane levels throughout the Arctic are usually 8 to 10 percent higher than the global baseline. When they flew over the shelf, they found methane at levels another 5 to 10 percent higher than the already elevated arctic levels.

The East Siberian Arctic Shelf, in addition to holding large stores of frozen methane, is more of a concern because it is so shallow. In deep water, methane gas oxidizes into carbon dioxide before it reaches the surface. In the shallows of the East Siberian Arctic Shelf, methane simply doesn’t have enough time to oxidize, which means more of it escapes into the atmosphere. That, combined with the sheer amount of methane in the region, could add a previously uncalculated variable to climate models.

“The release to the atmosphere of only one percent of the methane assumed to be stored in shallow hydrate deposits might alter the current atmospheric burden of methane up to 3 to 4 times,” Shakhova said. “The climatic consequences of this are hard to predict.”

Shakhova, Semiletov and collaborators from 12 institutions in five countries plan to continue their studies in the region, tracking the source of the methane emissions and drilling into the seafloor in an effort to estimate how much methane is stored there.

New evidence hints at global glaciation 716.5 million years ago

2010-03-07T03:14:00.002+05:30

In this photo from Canada's Yukon Territory, an iron-rich layer of 716.5-million-year-old glacial deposits (maroon in color) is seen atop an older carbonate reef (gray in color) that formed in the tropics.

Credit: Francis A. Macdonald/Harvard UniversityGeologists have found evidence that sea ice extended to the equator 716.5 million years ago, bringing new precision to a "snowball Earth" event long suspected to have taken place around that time.

Led by scientists at Harvard University, the team reports on its work this week in the journal Science. The new findings - based on an analysis of ancient tropical rocks that are now found in remote northwestern Canada - bolster the theory that our planet has, at times in the past, been ice-covered at all latitudes.
"This is the first time that the Sturtian glaciation has been shown to have occurred at tropical latitudes, providing direct evidence that this particular glaciation was a 'snowball Earth' event," says lead author Francis A. Macdonald, an assistant professor in the Department of Earth and Planetary Sciences at Harvard. "Our data also suggests that the Sturtian glaciation lasted a minimum of 5 million years."

The survival of eukaryotic life throughout this period indicates sunlight and surface water remained available somewhere on the surface of Earth. The earliest animals arose at roughly the same time, following a major proliferation of eukaryotes.

Even in a snowball Earth, Macdonald says, there would be temperature gradients on Earth and it is likely that ice would be dynamic: flowing, thinning, and forming local patches of open water, providing refuge for life.

"The fossil record suggests that all of the major eukaryotic groups, with the possible exception of animals, existed before the Sturtian glaciation," Macdonald says. "The questions that arise from this are: If a snowball Earth existed, how did these eukaryotes survive? Moreover, did the Sturtian snowball Earth stimulate evolution and the origin of animals?"

"From an evolutionary perspective," he adds, "it's not always a bad thing for life on Earth to face severe stress."

The rocks Macdonald and his colleagues analyzed in Canada's Yukon Territory showed glacial deposits and other signs of glaciation, such as striated clasts, ice rafted debris, and deformation of soft sediments. The scientists were able to determine, based on the magnetism and composition of these rocks, that 716.5 million years ago they were located at sea level in the tropics, at about 10 degrees latitude.

"Because of the high albedo of ice, climate modeling has long predicted that if sea ice were ever to develop within 30 degrees latitude of the equator, the whole ocean would rapidly freeze over," Macdonald says. "So our result implies quite strongly that ice would have been found at all latitudes during the Sturtian glaciation."

Scientists don't know exactly what caused this glaciation or what ended it, but Macdonald says its age of 716.5 million years closely matches the age of a large igneous province stretching more than 1,500 kilometers (932 miles) from Alaska to Ellesmere Island in far northeastern Canada. This coincidence could mean the glaciation was either precipitated or terminated by volcanic activity.

Climate change one factor in malaria spread

2010-03-06T23:08:00.000+05:30

Climate change is one reason malaria is on the rise in some parts of the world, new research finds, but other factors such as migration and land-use changes are likely also at play. The research, published in The Quarterly Review of Biology, aims to sort out contradictions that have emerged as scientists try to understand why malaria has been spreading into highland areas of East Africa, Indonesia, Afghanistan and elsewhere.

"We assessed … conclusions from both sides and found that evidence for a role of climate in the dynamics is robust," write study authors Luis Fernando Chaves from Emory University and Constantianus Koenraadt of Wageningen University in the Netherlands. "However, we also argue that over-emphasizing a role for climate is misleading for setting a research agenda, even one which attempts to understand climate change impacts on emerging malaria patterns."

Malaria, a parasitic disease spread to humans by mosquitoes, is common in warm climates of Africa, South America and South Asia. The development and survival, both of the mosquito and the malaria parasite are highly sensitive to daily and seasonal temperature patterns and the disease has traditionally been rare in the cooler highland areas. Over the last 40 years, however, the disease has been spreading to the highlands, and many studies link the spread to global warming. But that conclusion is far from unanimous. Other studies have found no evidence of warming in highland regions, thus ruling out climate change as a driver for highland malaria.

Chaves and Koenraadt re-examined more than 70 of these studies. They found that the studies ruling out a role for climate change in highland malaria often use inappropriate statistical tools, casting doubt on their conclusions.

For example, an oft-cited 2002 study of the Kericho highlands of western Kenya found no warming trend in the area. But when Chaves and Koenraadt ran the same temperature data from that study through three additional statistical tests, each test indicated a significant warming trend. Similar statistical errors plague other comparable studies, the researchers say.

In contrast, most studies concluding that climate change is indeed playing a role in highland malaria tend to be statistically strong, Chaves and Koenraadt found. But just because climate is one factor influencing malaria's spread does not mean it is the only one. What is needed, the researchers say, is a research approach that combines climate with other possible factors.

"Even if trends in temperature are very small, organisms can amplify such small changes and that could cause an increase parasite transmission," Chaves said. "More biological data will improve our overall understanding of malaria and will allow scientists to propose more general and accurate models on the impacts of climate change on malaria transmission."

The authors cite numerous factors that could interact with climate to influence malaria spread. They point to research showing that people migrating from lowlands may be introducing the malaria parasite into highland regions. Changes in farming practices may also play a role. Irrigation associated with more intensive farming may be creating more places for mosquitoes to breed. Another example comes from two studies that linked malaria increases in the Bure highlands of Ethiopia to increased maize farming. There, the immature and aquatic stages of mosquitoes thrive on a diet of maize pollen, and more mosquitoes can mean more malaria.

"A major future challenge will be to link up what happens with mosquitoes and parasites at the household level with long-term climate change scenarios at the continental scale," Koenraadt said.

The spread of malaria in highlands is of great concern to those who work to contain the disease. But understanding the many factors that influence the spread of highland malaria could help with efforts to control the disease worldwide, Chaves and Koenraadt conclude.

"In the light of global efforts towards malaria elimination, highland areas will be interesting starting points from where control efforts could interrupt transmission and aid in shrinking the world's malaria map." Koenraadt said.

Improved near-real-time tracking of 2010 El Niño reveals marine life reductions

2010-03-04T12:36:00.002+05:30

Researchers search for answers to warming coastal water, thinning marine populations

The ongoing El Niño of 2010 is affecting north Pacific Ocean ecosystems in ways that could affect the West Coast fishing industry, according to scientists at NOAA and Scripps Institution of Oceanography, UC San Diego.

Researchers with the California Cooperative Oceanic Fisheries Investigations (CalCOFI) at Scripps and NOAA's Southwest Fisheries Science Center report a stronger than normal northward movement of warm water up the Southern California coast, a high sea-level event in January and low abundances of plankton and pelagic fish - all conditions consistent with El Niño.

Sea surface temperatures along the entire West Coast are 0.5 to 1 degree Celsius (0.9 to 1.8 degrees Fahrenheit) warmer than normal and at points off Southern California are as much as 1.6 degrees Celsius (2.9 degrees Fahrenheit) higher than normal. The most unusually high temperatures were mapped around Catalina and San Clemente islands. While strong winter storms caused an increase in coastal sea levels, scientists are investigating whether the higher sea levels are primarily a result of El Niño, a cyclical phenomenon characterized by warming eastern equatorial Pacific Ocean waters.

"Based on our previous experience of El Niño in California, it is likely to reduce ocean production below normal, with possible effects extending to breeding failure of seabirds, and much lower catches in the market squid fishery," said Sam McClatchie, a fisheries oceanographer at NOAA's Southwest Fisheries. "However, predictions are never certain, and CalCOFI and NOAA ocean-observing systems will continue to provide essential monitoring of the situation."

A combination of satellite remote sensing and field measurements is offering scientists a broader view of the evolution of this El Niño that was not available during previous El Niños, which were especially strong in 1982-83 and 1997-98. Internet technology aboard CalCOFI research vessels is delivering that information faster.

"You can post data the same day it's collected," said CalCOFI information manager Jim Wilkinson of Scripps Oceanography. "It used to take six months to work up some of the data and interpret it."

NOAA Southwest Fisheries oceanographer Frank Schwing said scientists' analytical tools provide better ways to assess the strength of anomalies such as warming that are associated with El Niño.

"We're taking a much more ecosystem-based approach to managing the system," said Schwing. "Because we are more on top of the observations, we can give a more timely heads-up to scientists and managers who are interested in the effects of El Niño."

The two research centers use data collected by satellites and buoy-mounted instruments to measure sea surface temperature. CalCOFI researchers embark on quarterly cruises off the California coast to collect vertical temperature profiles in the upper reaches of the water column. They also count eggs of commercially important fishes such as sardines and anchovies as well as measure plankton volumes to estimate the amount of "production" available to marine organisms. NOAA's Advanced Survey Technologies Group assesses fish populations through acoustic surveys. In contrast with the last major El Niño, Scripps now deploys Spray gliders, diving robots that now gather ocean temperature and other data along transects between CalCOFI stations.

The NOAA and CalCOFI scientists have observed a drop in biological abundance, or productivity, that appears to be related to the northward movement of warm water from the equator. The flow arrives in pulsing Kelvin waves that are detected by sea level and altimeter monitors and coastal tidal gauges. The layer of warm water often stifles the upwelling of nutrients from lower ocean depths that sustain larger populations of fishes and invertebrates.

The researchers reported finding fewer hake and anchovy eggs than usual in the most recent CalCOFI surveys. Sanddab and flounder eggs dominated the samples. Most were collected in a small area east of the Channel Islands.

The scientists added that if El Niño conditions continue, they are likely to be characterized by weaker than normal upwelling and lower biological production. El Niño conditions are forecast to persist into spring. If so, greater biological anomalies than have already been observed may develop.

World environment ministers signal resolve to realize sustainable development

2010-02-28T02:07:00.002+05:30

In the first landmark Declaration issued by ministers of the environment in a decade, governments pledged to step up the global response to the major environmental and sustainability challenges of this generation.

The wide-ranging Nusa Dua Declaration, agreed today in the closing session of the UN Environment Programme's (UNEP) Governing Council/Global Ministerial Environment Forum, underlines the vital importance of biodiversity, the urgent need to combat climate change and work towards a good outcome in Mexico later in the year and the key opportunities from accelerating a transition to a low-carbon resource-efficient Green Economy.

The statement also highlights the need to improve the overall management of the global environment, accepting that that 'governance architecture' has in many ways become too complex and fragmented.

An important step forward was made earlier in the week in the areas of chemicals, hazardous wastes and human health. Governments agreed at an Extraordinary Meeting to have more cooperative action by the three relevant treaties-the Basel, Rotterdam and Stockholm conventions - as a first step to boosting their delivery within countries.

Achim Steiner, UN Under-Secretary and UNEP Executive Director, said: "The ministers responsible for the environment, meeting just over a month after the climate change conference in Copenhagen, have spoken with a clear, united and unequivocal voice."

"Faced with the continued erosion of the natural environment, the persistent and emerging challenges of chemical pollution and wastes and the overarching challenge of issues such as climate change, the status quo is not an option and change is urgently needed," he added.

"This change starts with recognition that the way we are managing the environmental dimension of sustainable development is currently too complex and fragmented. Change is needed here and the ministers signaled their determination to realize this through a political process," said Mr. Steiner.

"But the ministers also recognized that action towards a Green Economy - one able to meet multiple challenges and seize multiple opportunities- is taking route in economies across the globe. Accelerating this is a key element of the Nusa Dua Declaration and one that can direct future action towards realising the kinds of transitions needed on a planet of six billion people, rising to nine billion by 2050," he added.

The Declaration, the first by world environment ministers since they met in Malmö, Sweden in 2000, will be transmitted to the UN General Assembly later this year.

There governments will begin preparations for a landmark conference in Brazil, called Rio plus 20.

Rio plus 20 comes two decades after the first Rio Earth Summit, which gave birth to many of the key treaties, ranging from climate change to biodiversity, which to date have defined the international response to environmental challenges.

Green Economy

Case studies, illuminating the multiple benefits of a Green Economy, were presented to delegates in advance of a landmark Green Economy report to be released later this year.

Uganda

- The area of land under organic agriculture has risen from 185,000 hectares in 2004 to close to 300,000 hectares in 2008, with a 360 per cent rise in the number of farmers engaged in the sector - from 45,000 certified farmers to 207,000.

- Certified organic exports have risen from US$3.7 million in 2003-2004 to US$22.8 million in 2007-2008.

- The country is also contributing to combating climate change. C02 emissions per hectare are up to 68 per cent less than on conventionally farmed land, with studies indicating that organic fields sequester 3-8 tonnes more carbon per hectare.

China

- More than 10 per cent of Chinese households rely on the sun to heat their water, with more than 40 million solar water heating systems in place.

- The renewable energy sector as a whole generates output worth US$17 billion and employs 1 million workers, of which 600,000 are employed in solar thermal panel making and installing products, such as solar water heaters.

- The warm water from solar water heaters is also reducing rheumatoid arthritis among women as they now have hot water for laundry and dishwashing done by hand instead of only cold water.

Brazil

- The city of Curitiba has, through sustainable urban planning and transport, cut per capita loss from severe congestion. It is about 6.7 and 11 times less than per capita losses in Rio de Janeiro and Sao Paulo.

- In 2002, Curitiba's annual fuel losses from severe traffic congestion equaled R$1.98 million (US$930,000). On per capita terms, this loss is about 13 times and 4.3 times less than those in Sao Paulo and Rio de Janeiro.

- Curitiba's fuel usage is also 30 per cent lower than in Brazil's other major cities.

Other Highlights of the UNEP GC/GMEF

The Intergovernmental Panel on Climate Change (IPCC)

The delegates were addressed by Dr. Rajendra Pachauri, chair of the IPCC which is co- hosted by UNEP and the World Meteorological Organization.

Ministers re-affirmed the central importance of the IPCC and the importance of sound science upon which to base a response to climate change.

However, as a result of recent criticism of the IPCC and some key errors in the body's fourth assessment report, several governments called for an independent review of the IPCC.

Full details of the review and its scope will be announced next week with the report to be presented to the IPCC Plenary taking place in the Republic of Korea in October.

Several key decisions were adopted, including ones on oceans put forward by the Government of Indonesia and the strengthening the environment via the Environmental Management Group which UNEP hosts.

Intergovernmental Platform on Biodiversity and Ecosystem Services (IPBES)

Many experts believe a science panel or platform for biodiversity and ecosystems is needed to assist governments in combating the erosion of plants and animals and ecosystems such as forests, freshwaters and soils.

Governments agreed to a final meeting in June 2010, halfway through the UN's International Year of Biodiversity, to decide whether to establish such a body.

Haiti

Delegates also backed UNEP's support to Haiti in the wake of the devastating earthquake of 12 January 2010 and called on the organization to assist the UN country team to incorporate environmental issues in the rehabilitation and reconstruction and restoration phases.

Gaza

Delegates asked UNEP to assist in implementing recommendations from its environmental assessment of the Gaza Strip compiled following the escalation of hostilities in December 2008 through to January 2009.

The assessment covers issues such as solid waste management, pollution and the acute decline of Gaza's underground water supplies.

Ice shelves disappearing on Antarctic peninsula

2010-02-24T21:49:00.001+05:30

Ice shelves are retreating in the southern section of the Antarctic Peninsula due to climate change. This could result in glacier retreat and sea-level rise if warming continues, threatening coastal communities and low-lying islands worldwide.

Research by the U.S. Geological Survey is the first to document that every ice front in the southern part of the Antarctic Peninsula has been retreating overall from 1947 to 2009, with the most dramatic changes occurring since 1990. The USGS previously documented that the majority of ice fronts on the entire Peninsula have also retreated during the late 20th century and into the early 21st century.

The ice shelves are attached to the continent and already floating, holding in place the Antarctic ice sheet that covers about 98 percent of the Antarctic continent. As the ice shelves break off, it is easier for outlet glaciers and ice streams from the ice sheet to flow into the sea. The transition of that ice from land to the ocean is what raises sea level.

“This research is part of a larger ongoing USGS project that is for the first time studying the entire Antarctic coastline in detail, and this is important because the Antarctic ice sheet contains 91 percent of Earth’s glacier ice,” said USGS scientist Jane Ferrigno. “The loss of ice shelves is evidence of the effects of global warming. We need to be alert and continually understand and observe how our climate system is changing.”

The Peninsula is one of Antarctica’s most rapidly changing areas because it is farthest away from the South Pole, and its ice shelf loss may be a forecast of changes in other parts of Antarctica and the world if warming continues.

Retreat along the southern part of the Peninsula is of particular interest because that area has the Peninsula’s coolest temperatures, demonstrating that global warming is affecting the entire length of the Peninsula.

The Antarctic Peninsula’s southern section as described in this study contains five major ice shelves: Wilkins, George VI, Bach, Stange and the southern portion of Larsen Ice Shelf. The ice lost since 1998 from the Wilkins Ice Shelf alone totals more than 4,000 square kilometers, an area larger than the state of Rhode Island.

The USGS is working collaboratively on this project with the British Antarctic Survey, with the assistance of the Scott Polar Research Institute and Germany’s Bundesamt fur Kartographie und Geodäsie. The research is also part of the USGS Glacier Studies Project, which is monitoring and describing glacier extent and change over the whole planet using satellite imagery.

University of Oklahoma geologists look for answers in Antarctica

2010-02-24T21:05:00.000+05:30

Focusing on a controversial hypothesis that ice existed at the equator some 300 million years ago during the late Paleozoic Period, two University of Oklahoma researchers originated a project in search of clues to the Earth’s climate system.

“The Paleozoic Period was a rare time in history,” says Gerilyn Soreghan, OU professor of geology. “Broadly speaking, it was the last time our planet experienced the type of climate system we have today and in the recent past.” Soreghan believes comparing more modern systems in a range of different climates might help support her hypothesis.

Soreghan and Elwood Madden, assistant professor of geochemistry, want to search for answers in four distinct environments: the cold-dry environment found in Antarctica, the cold-wet environment found in Norway, the hot-wet environment found in Puerto Rico and the hot-dry environment found in the Mojave Desert.

A National Science Foundation project proposal was submitted and the NSF responded with its own proposal recommending a pilot project to the most extreme location proposed – Antarctica. Soreghan was surprised and excited by the NSF proposal. She then began preparing for the journey of a lifetime.

The OU team flew to New Zealand at the end of December and promptly went to the clothing distribution center to be outfitted for the trip. Even though Soreghan and two graduate students would arrive in Antarctica during the summer season, the extremely cold weather proved challenging.

The trip to McMurdo Sound, Antarctica, took roughly 5 hours. Upon arrival, the team met with experienced University of Maine researcher Brenda Hall, who helped the team get ready for the next few weeks. They needed food, radios, tents and other essential equipment for the expedition.

They pinpointed the glaciers where they would take water and sediment samples. When they were ready, a helicopter dropped them in the Dry Valleys and they began collecting samples in one of the smallest rivers in Wright Valley.

Summer in Antarctica was colder and drier than usual and the task of collecting samples downstream was more difficult than expected. The research team would go back on another day to collect additional samples.

The team moved to the Onyx River, the largest river in the valley. Sampling here was more successful as the river flows roughly six weeks during the summer. The water samples taken from the river showed non-random patterns – a good sign, according to Soreghan.

The team took samples at the proximal or closest location to find out what is happening where erosion begins. Glacial systems are typically dominated by physical weathering, a process where the glacier glides across bedrock and grinds it up to create lots of surface area for water to interact with it.

However, many glaciers in Antarctica are frozen to their beds, such that physical grinding is much less important than in temperate glacial systems. Chemical weathering predominates over physical weathering in warmer climates.

During analyses, researchers will examine the chemistry of the sediments and water to determine if there might be certain “markers” or indicators unique to erosion in this type of climate. An electron scanning microscope will allow them to see what kind of physical erosion is going on. Glacial striations or grooves indicate grinding or patterns of grinding.

Analyzing the samples will take about year, but preliminary samples taken from the Wichita Mountains in Oklahoma can be compared with the Antarctic samples to see if there are similarities.

New insights into helping marine species cope with climate change

2010-02-21T20:47:00.002+05:30

Move, adapt or die. Those are the options marine plants and animals have in the face of climate change, said Stanford biologist Steve Palumbi, who has been exploring how to help them go with the first two options, rather than the third. He's come up with some surprising answers.

Palumbi will be discussing the results of his research in two talks at the annual meeting of the American Association for the Advancement of Science in San Diego.

How to design marine protected areas to best benefit a wide variety of plant and animal species is the focus of a talk he'll give on Saturday, Feb. 20. The most practical kind of natural reserve is one that benefits species and local human populations, but Palumbi said striking that balance isn't always easy. Many people have argued that bigger is better when it comes to marine reserves, but Palumbi has data suggesting that is not always the case.

In a separate Topical Lecture he'll give on Sunday, Feb. 21, Palumbi will present his findings on how marine species are reacting to climate change, including new work on coral species in the Pacific that have poor powers of dispersal but a surprising ability to cope with higher temperatures.

Palumbi is director of Stanford's Hopkins Marine Station and a senior fellow at the university's Woods Institute for the Environment.

If you can't move, then you'd better adjust

Many species, such as those along the west coast of California, can simply migrate north to colder waters. But other animals, such as the coral that Palumbi's team has studied in Fiji and American Samoa, won't be moving anytime soon.

"Each coral population is trapped on its own island, and as global climate changes around them, the populations are essentially stuck where they are. They have to go to the second stage, which is to adapt," Palumbi said.

Marine scientists have predicted that coral reefs will be at risk of extinction due to high ocean temperatures caused by climate change, but Palumbi has found a species of coral that may have a better chance of adapting.

Palumbi's team studied corals growing in shallow lagoons that face intense heat during noontime summer low tides. The team knew these corals were resistant to brief heating but were surprised to find that the corals survived five to six days of high water temperatures. Baking in the tropical summer sun at low tide for 4 to 6 hours a day seems to have better prepared these corals for global warming temperatures.

"When we tested these corals against high temperatures for extended periods of time, they showed all the evidence of having higher resilience," Palumbi said. "It looks like the corals have adapted or acclimated to that stress and have a better chance of resisting high global warming temperatures." How long this resilience will last, and whether all corals can do this, are remaining questions.

Does size matter for marine reserves?

A major response to climate change is to protect reefs from other human-caused stresses such as overfishing. And as a result, a large number of Marine Protected Areas have been implemented in the Pacific. Some are the size of a football field. Some are the size of California. Is bigger better?

To determine how much difference the size of a protected area might make, Palumbi analyzed data from a set of small reserves in Fiji, from the Phoenix Islands and from the Papahanaumokuakea Reserve in Hawaii, the largest marine reserve in the world. All three areas are set aside by government agencies.

The Papahanaumokuakea Marine National Monument covers 360,000 square kilometers (139,000 square miles) in Northwest Hawaii and is a "no-take" reserve, which means nothing may be removed, including fish.

The Phoenix Islands Protected Area, which lies in the central Pacific Ocean between Hawaii and Fiji, is over 408,000 square kilometers (158,000 square miles). There are seven no-take reserves in this area, each about 39 kilometers (24 miles) across.

However, in densely populated areas, smaller reserves are more common. Fiji has 246 such protected areas, each averaging about 2 to 3 square kilometers (about a square mile).

"Small sets of marine protected areas are much more convenient: People can fish in between them or go around them easily. Species found within the marine protected areas easily spill out into the surrounding areas, potentially increasing fishing productivity," Palumbi said.

However, wide stretches of protected ocean allow species to spread more easily than small areas, where they risk being caught by fishermen between the reserves. Therefore, small reserves must be well matched to the plants and animals they are protecting because each species spreads at different rates, Palumbi said.

"Species have lots of different dispersal abilities, so it's very hard to have a marine protected area network that works equally well for all different species. You have to tailor the network of reserves to the species," he said.

Though small reserves meet the needs of fewer species than those of larger reserves, setting aside enormous areas of ocean is not that simple. Scientists and policymakers must consider local residents who depend on fisheries for their well-being.

"With heavy human populations, the political, social and economic problems of a big marine protected area are paramount and you've got to go to another strategy. But it's a strategy with limitations because it's hard to design an area perfectly for all species that need protection," Palumbi said. The most effective reserve is one that balances preservation of species with human needs, he said. Finding that balance is the challenge.

Global warming may hurt some poor populations

2010-02-21T18:23:00.001+05:30

The impact of global warming on food prices and hunger could be large over the next 20 years, according to a new Stanford University study. Researchers say that higher temperatures could significantly reduce yields of wheat, rice and maize – dietary staples for tens of millions of poor people who subsist on less than USD1 a day. The resulting crop shortages would likely cause food prices to rise and drive many into poverty.

But even as some people are hurt, others would be helped out of poverty, says Stanford agricultural scientist David Lobell.

"Poverty impacts depend not only on food prices but also on the earnings of the poor," said Lobell, a center fellow at Stanford's Program on Food Security and the Environment (FSE). "Most projections assume that if prices go up, the amount of poverty in the world also will go up, because poor people spend a lot of their money on food. But poor people are pretty diverse. There are those who farm their own land and would actually benefit from higher crop prices, and there are rural wage laborers and people that live in cities who definitely will be hurt."

Lobell and his colleagues recently conducted the first in-depth study showing how different climate change scenarios could affect incomes of farmers and laborers in developing countries. He will present the results on Feb. 20 at the annual meeting of the American Association for the Advancement of Science in San Diego.

Household incomes

In the study, Lobell, former FSE researcher Marshall Burke and Purdue University agricultural economist Thomas Hertel focused on 15 developing countries in Asia, Africa and Latin America. Hertel has developed a global trade model that closely tracks the consumption and production of rice, wheat and maize on a country-by-country basis. The model was used to project the effects of climate change on agriculture within 20 years and the resulting impact on prices and poverty.
Using a range of global warming forecasts, the researchers were able to project three different crop-yield scenarios by 2030:

"Low-yield" – crop production is toward the low end of expectations.
"Most likely" – projected yields are consistent with expectations.
"High-yield" – production is higher than expected.

"One of the limitations of previous forecasts is that they don't consider the full range of uncertainties – that is, the chance that things could be better or worse than we expect," Lobell said. "We provided Tom those three scenarios of what climate change could mean for agricultural productivity. Then he used the trade model to project how each scenario would affect prices and poverty over the next 20 years.
"The impacts we're talking about are mainly driven by warmer temperatures, which dry up the soil, speed up crop development and shut down biological processes, like photosynthesis, that plants rely on," he added. "Plants in general don't like it hotter, and in many climate forecasts, the temperatures projected for 2030 would be outside the range that crops prefer."

Results

The study revealed a surprising mix of winners and losers depending on the projected global temperature. The "most likely" scenario projected by the International Panel on Climate Change is that global temperatures will rise 1.8 degrees Fahrenheit (1 degree Celsius) by 2030. In that scenario, the trade model projected relatively little change in crop yields, food prices and poverty rates.
But under the "low-yield" scenario, in which temperatures increase by 2.7 F (1.5 C), the model projects a 10 to 20 percent drop in agricultural productivity, which results in a 10 to 60 percent rise in the price of rice, wheat and maize. Because of these higher prices, the overall poverty rate in the 15 countries surveyed was expected to rise by 3 percent.

However, an analysis of individual countries revealed a far more complicated picture. In 11 of the 15 countries, poor people who owned their own land and raised their own crops actually benefitted from higher food prices, according to the model. In Thailand, for example, the poverty rate for people in the non-agricultural sector was projected to rise 5 percent, while the rate for self-employed farmers dropped more than 30 percent – in part because, as food supplies dwindled, the global demand for higher-priced crops increased.

"If prices go up and you're tied to international markets, you could be lifted out of poverty quite considerably," Lobell explained. "But there are a lot of countries, like Bangladesh, where poor people are either in urban areas or in rural areas but don't own their own land. Countries like that could be hurt quite a lot. Then there are semi-arid countries – like Zambia, Mozambique and Malawi – where even if prices go up and people own land, productivity will go down so much that it can't make up for those price increases. In the 'low-yield' scenario, those countries would see higher poverty rates across all sectors."

Under the "high-yield" scenario, in which global temperatures rise just 0.9 F (0.5 C), crop productivity increased. The resulting food surplus led to a 16 percent drop in prices, which could be detrimental to farm owners. In Thailand, the poverty rate among self-employed farmers was projected to rise 60 percent, while those in the non-agriculture sector saw a slight drop in poverty. In Zambia, Mozambique, Malawi and Uganda, poverty in the non-farming sector was projected to decline as much as 5 percent.

Risk management

Lobell said that, although the likelihood of the "low-yield" or "high-yield" scenario occurring is only 5 percent, it is important for policymakers to consider the full range of possibilities if they want to help countries adapt to climate change and ultimately prevent an increase in poverty and hunger.
"It's like any sort of risk management or insurance program," he said. "You have to have some idea of the probability of events that have a big consequence. It's also important to keep in mind that any change, no matter how extreme, will benefit some households and hurt others."

Understanding global climate change through new breakthroughs in polar research

2010-02-19T19:51:00.002+05:30

The latest findings from research on Antarctica's rich marine life are presented this week at the American Association for the Advancement of Science

The latest findings from research on Antarctica's rich marine life are presented this week at the American Association for the Advancement of Science (AAAS). Marine Biologist Huw Griffiths from British Antarctic Survey (BAS) is involved in a major international investigation into the distribution and abundance of Antarctica's vast marine biodiversity – the Census of Antarctic Marine Life (CAML).

Griffiths presents results from the census – which began in 2005 – and describes how the investigation provides the benchmark for future studies on how the extraordinary and diverse range of sea-floor creatures living in Antarctica's chilly waters will respond to predicted environmental change.

More than 6,000 different species living on the sea-floor have been identified so far and more than half of these are unique to the icy continent. A combination of long-term monitoring studies, newly gathered information on the marine life distribution and global ocean warming models, enable the scientists to identify Antarctica's marine 'biodiversity hotspots'.

Griffiths describes how krill populations (the shrimp-like invertebrates eaten by penguins, whales and seals) are reducing as a result of a decrease in sea-ice cover. A much smaller crustacean (copepods) is dominating the area once occupied by them. This shifts the balance of the food web to favour predators, like jellyfish, that are not eaten by penguins and other Southern Ocean higher predators. Sea-ice reduction is also affecting penguins that breed on the ice.

Griffiths says, "The Polar Regions are amongst the fastest warming places on Earth and predictions suggest that in the future we'll see warming sea surface temperatures, rising ocean acidification and decreasing winter sea ice - all of which have a direct effect on marine life.

"Marine animals spent millions of years adapting to the freezing, stable conditions of the Antarctic waters and they are highly sensitive to change. This means that from the scientist's perspective they are excellent indicators of environmental change. The polar oceans are rich in biodiversity. If species are unable to move or adapt to new conditions they could ultimately die out. The loss of any unique species is therefore a loss of global diversity."

CryoSat to observe Earth's ice cover

2010-02-15T20:29:00.008+05:30

The European Space Agency is about to launch the most sophisticated satellite ever to investigate the Earth's ice fields and map ice thickness over water and land: lift-off scheduled for 25 February.

ESA's ice mission satellite CryoSat will be placed into orbit 700 km above Earth by a Russian Dnepr rocket to be launched from the Baikonur Cosmodrome in Kazakhstan.

Lift-off is scheduled to take place at 14:57 CET (13:57 UTC) on Thursday 25 February 2010. The launcher is operated by the international space company Kosmotras.

CryoSat will be the third of ESA's Earth Explorer satellites in orbit, following on from GOCE (launched in March 2009) and SMOS (launched in November 2009). It was originally due to be the first in the Earth Explorer series, but the first satellite was lost as a result of a launcher failure in October 2005. The 700 kg CryoSat spacecraft – whose name comes from the Greek kruos meaning icy cold–carries the first all-weather microwave radar altimeter. The instrument has been optimised for determining changes in the thickness of both floating sea ice, which can be up to several metres, and polar land ice sheets, which in Antarctica can be up to five kilometres. The mission will deliver data on the rate of change of the ice thickness accurate to within one centimetre.

Recent record-lows in the extent of summer Arctic sea-ice cover demonstrate that significant changes are occurring in the polar regions. Ice cover has been mapped from space for many years by satellites such as Envisat. But to understand more about how climate change is affecting these sensitive regions, there is also an urgent need to determine how ice thickness is changing. Data from CryoSat will lead to a better understanding of the dynamics of ice mass, provide the scientific community with valuable information on this variable and contribute to climate change studies.

'Smart Grids' – climate infrastructure for the 21st century

2010-02-05T00:23:00.000+05:30

There's no need to worry that renewable energy can't keep the lights on, concludes a new study by Greenpeace and the European Renewable Energy Council (EREC).

The report: Renewables 24/7 – Infrastructure needed to save the climate shows how the world’s power grids could be transformed to support a power mix comprising 90% renewable energy by 2050. The transformation would be achieved at a modest level of investment, presents a huge market opportunity for ICT companies, and would enable huge cuts in greenhouse gas emissions.

Renewables 24/7 is part of Greenpeace’s Energy [R]evolution scenario, a comprehensive vision for a climate friendly global energy supply.

The study explains how mini-grids and smart-grids could be connected intelligently with a super grid to provide reliable around the clock supply without any need for coal fired or nuclear power plants. The study also proposes a specific grid reinforcement and expansion plan for Europe, including a cost analysis.

"With smart grids we basically merge the internet with the electricity grid", says Greenpeace International senior energy expert, Sven Teske. "Building up smart grids is a huge business opportunity, especially for IT companies. In Europe the annual investment needed will be around EUR5 billion. That would cost a European household less than five Euros a year. To unlock this urgently needed investment in new climate friendly infrastructure, we need energy policies which support the transition towards close to 100% renewables in the power sector," Teske added.

Smart Grids combine distributed power sources to create virtual power plants. In this way small wind, solar, geo-thermal and bio-gas facilities can provide the same power as a traditional power plant but with greater efficiency and flexibility – and far lower CO2 emissions.

Super Grids use High Voltage Direct Current (HVDC) lines to transfer power huge distances with great efficiency. This will allow surplus wind energy from the North Sea to be stored in Norweigan Hydro systems, or solar energy from Spain to be delivered to Germany.

The 2008 EU 27 Energy [R]evolution scenario showed how Europe could achieve 90% renewable energy supply by 2050. The new report compared 30 years of weather data with European annual demand curves and concluded that with the existing grid there is only a 0.4 percent -- or 12 hours a year -- chance that high demand correlates with low solar and wind generation. The proposed grid reinforcement would remove even this small uncertainty and guarantee reliable power.

This new publication comes on the heels of a political declaration of a 'North Seas Offshore Wind Initiative'. On 7th December 2009 Ministers of the North Sea Countries announced that they would develop an offshore grid to enhance the integration of renewable energies such as offshore wind farms. The offshore grid will be one of the first steps toward a European super grid.

"We welcome the EU initiative for a better use of renewable energies which shows we can deliver a smart, super grid and expand renewable energy supplies in parallel", said Christine Lins Director General from EREC.

"The global market for renewable energy could grow at a double digit rates until 2050, and overtake the size of today’s fossil fuel industry. Currently, the renewable energy market is worth EUR100 billion and doubling in size every three years. The global renewable market will go hand in hand with the development of smart grids, when the combined share of wind and solar photovoltaic power exceeds roughly one third of the total power generation."

Copies of the Renewable 24/7 report can be downloaded at: http://www.greenpeace.org/international/press/reports/renewables-24-7

Governments challenged to deliver more ambitious emissions reductions targets

2010-02-03T00:20:00.000+05:30

Fifty-five governments have submitted pledges to the United Nations Framework Convention on Climate Change to cut and limit their greenhouse gas emissions by 2020, as part of the Copenhagen Accord. In doing so, they have accepted the Accord's objective of avoiding dangerous climate change by keeping global warming below 2 degrees C. Greenpeace calls on the 55 governments to take on tougher new emissions targets or face charges that they are ‘greenwashing’ their plans.

Paragraph 2 of the Copenhagen Accord specifically states, "We agree that deep cuts in global emissions are required... with a view to reduce global emissions so as to hold the increase in global temperature below 2 degrees Celsius, and take action to meet this objective..." This level of warming is regarded as a critical threshold beyond which there may be irreversible large-scale impacts on the environment.

"The world is waiting for these 55 governments to urgently outline what each of them intends to do to ensure global warming is kept under 2 degrees C," said Bernhard Obermayr, of Greenpeace. "They have to walk the talk if the Copenhagen Accord is to be anything other than a greenwashing tool for the failure of world leaders during last December's climate summit."

Staying well below the warming threshold requires industrialised nations to cut their greenhouse gas emissions by 40% below 1990 levels by 2020 and provide substantial funding to developing countries which need to reduce their projected growth in emissions by 15-30% by the same date.

Current targets by industrialised countries fall far short of this. Together they amount only to an 11-19% reduction in their overall emissions. The effect of proposed forestry credits mean effective cuts in emissions from fossil fuel use would be lower still. These commitments mean an average global temperature increase of more than 3 degrees C, compared to pre-industrial times. As a new Greenpeace briefing highlights, the environmental and social implications could be catastrophic.

Greenpeace has compared pledges made by the 55 governments prior to or during the Copenhagen summit against those that had by yesterday been submitted to the UN. The comparison shows a slight slackening of international effort to combat climate change. This is due to Canada downgrading its already weak emissions reduction target to bring it into line with that of the United States.

"Governments are going in reverse as regards action to combat climate change," said Bernhard Obermayr. "If they fail to outline how they are going to prevent warming from reaching the agreed threshold of 2 degrees C, concerned citizens will realise they have just been sold the biggest climate lie of all."

Copenhagen Accord recycles old climate commitments, leaving the world heading for catastrophic climate change

2010-02-01T00:15:00.001+05:30

With the passing of the Copenhagen Accord's 31 January deadline for its supporters to submit their pledges to curb greenhouse gas emissions, the absence of strengthened commitments has failed to meet the Accord's stated objective of taking action to limit global warming to under 2 degrees C (3.6 degrees F), a critical threshold for avoiding the worst impacts of climate change.

The 31 January deadline was the most immediate ‘action point’ in the non-binding Accord drawn up during last December's UN Copenhagen climate summit. It proved to have no impact on influencing major emitting nations to improve upon emission reduction commitments they had already made prior to the summit.

Together these commitments would mean an average global temperature increase of more than 3 degrees C (5.4 degree F), compared to pre-industrial times, setting the world on a path towards catastrophic climate change.

As summarised in a new Greenpeace briefing that examines the implications of current emissions pledges, warming of even half this level would have devastating social, environmental and economic impacts.

"Supporters of the Accord have failed to make emissions pledges which are strong enough to avert dangerous climate change," said Bernhard Obermayr, of Greenpeace. "The Accord’s 31 January deadline was no more than a cynical PR exercise allowing governments to recycle existing pledges and dress them up as effective action. It is the start of the Copenhagen 'greenwash'. The Accord is no substitute for the fair, ambitious and legally binding treaty demanded by millions of people who are concerned about climate change or are being affected by its impacts."

Existing industrialised country targets amount to only an 11-19% reduction in their emissions. The effect of proposed forestry credits mean effective cuts in emissions from fossil fuel use would be lower still.

To stay well below the critical warming threshold of 2 degrees C beyond which there may be irreversible large-scale impacts on the environment requires far greater commitment by all countries.

Industrialised nations must cut their greenhouse gas emissions by 40% below 1990 levels and developing countries need to reduce their projected growth in emissions by 15-30%, both by 2020. The industrialised world also needs to provide developing countries with new and additional funding of at least USD 140 billion annually to support clean energy and other mitigation activities, forest protection and adaptation. All of which must be enshrined in a legally binding agreement.

In stark contrast to the lack of tough new emissions reduction pledges by the rich industrialised world, the Republic of the Marshall Islands, one of the lowest-lying Pacific island nations, says it will cut its own emissions by 40% by 2020 - precisely the action required from industrialised countries. The Marshall Islands lies only 2 metres above sea level and is in danger of being wiped off the map. The industrialised world has been shamed for its inaction by one of the most vulnerable nations on the planet.

The Copenhagen Accord is no more than a weak political declaration. Having not delivered on its 31 January deadline for effective emissions pledges, this raises the question as to whether its other ambitions, such as realising fast-track funding by 2012 and multibillion dollar long-term support for developing and vulnerable nations, will suffer the same fate.

"Today is the day for an obituary about the Copenhagen Accord's objective of protecting the climate," said Bernhard Obermayr. "Greenpeace remains insistent that a fair, ambitious and legally binding deal can be concluded later this year, in Mexico. But we are dismayed that the UN's top climate official and the Danish environment minister, acting as president of the UN process, are so early in the year downplaying the chances. This risks being a self-fulfilling prophecy. We urge the UN to redouble its efforts to conclude the treaty the world so desperately needs. We call on the government of Mexico to continue playing an increasingly prominent and positive role to ensure this is achieved."

Urban 'green' spaces may contribute to global warming

2010-01-20T01:48:00.000+05:30

Amy Townsend-Small, Earth system science postdoctoral researcher, found that management of urban "green" spaces emits more greenhouse gases than the plots take in and store. | Photo by Steve Zylius / University CommunicationsUniversity of California, Irvine study finds Turfgrass management creates more greenhouse gas than plants remove from atmosphere

Dispelling the notion that urban “green” spaces help counteract greenhouse gas emissions, new research has found – in Southern California at least – that total emissions would be lower if lawns did not exist.

Turfgrass lawns help remove carbon dioxide from the atmosphere through photosynthesis and store it as organic carbon in soil, making them important “carbon sinks.” However, greenhouse gas emissions from fertiliser production, mowing, leaf blowing and other lawn management practices are four times greater than the amount of carbon stored by ornamental grass in parks, a UC Irvine study shows. These emissions include nitrous oxide released from soil after fertilisation. Nitrous oxide is a greenhouse gas that’s 300 times more powerful than carbon dioxide, the Earth’s most problematic climate warmer.

“Lawns look great – they’re nice and green and healthy, and they’re photosynthesising a lot of organic carbon. But the carbon-storing benefits of lawns are counteracted by fuel consumption,” said Amy Townsend-Small, Earth system science postdoctoral researcher and lead author of the study, forthcoming in the journal Geophysical Research Letters.

The research results are important to greenhouse gas legislation being negotiated. “We need this kind of carbon accounting to help reduce global warming,” Townsend-Small said. “The current trend is to count the carbon sinks and forget about the greenhouse gas emissions, but it clearly isn’t enough.”

Turfgrass is increasingly widespread in urban areas and covers 1.9 percent of land in the continental U.S., making it the most common irrigated crop.

In the study, Townsend-Small and colleague Claudia Czimczik analysed grass in four parks near Irvine, Calif. Each park contained two types of turf: ornamental lawns (picnic areas) that are largely undisturbed, and athletic fields (soccer and baseball) that are trampled and replanted and aerated frequently.

The researchers evaluated soil samples over time to ascertain carbon storage, or sequestration, and they determined nitrous oxide emissions by sampling air above the turf. Then they calculated carbon dioxide emissions resulting from fuel consumption, irrigation and fertiliser production using information about lawn upkeep from park officials and contractors.

The study showed that nitrous oxide emissions from lawns were comparable to those found in agricultural farms, which are among the largest emitters of nitrous oxide globally.

In ornamental lawns, nitrous oxide emissions from fertilisation offset just 10 percent to 30 percent of carbon sequestration. But fossil fuel consumption for management, the researchers calculated, released about four times more carbon dioxide than the plots could take up. Athletic fields fared even worse, because – due to soil disruption by tilling and resodding – they didn’t trap nearly as much carbon as ornamental grass but required the same emissions-producing care.

“It’s impossible for these lawns to be net greenhouse gas sinks because too much fuel is used to maintain them,” Townsend-Small concluded.

Previous studies have documented lawns storing carbon, but this research was the first to compare carbon sequestration to nitrous oxide and carbon dioxide emissions from lawn grooming practices.

The UCI study was supported by the Kearney Foundation of Soil Science and the U.S. Department of Agriculture.

Measuring carbon dioxide over the ocean

2010-01-20T01:43:00.000+05:30

Reliable measurements of the air-sea flux of carbon dioxide – an important greenhouse gas – are needed for a better understanding of the impact of ocean-atmosphere interactions on climate. A new method developed by researchers at the National Oceanography Centre, Southampton (NOCS) working in collaboration with colleagues at the Bjerknes Center for Climate Research (Bergen, Norway) promises to make this task considerably easier.

Infrared gas sensors measure carbon dioxide based on its characteristic absorption spectra and are used to evaluate the air-sea flux of the gas. So-called closed-path sensors precondition air before measurements are made, while open-path sensors can be used to measure the air in situ.

One advantage of using open-path sensors at sea is that wind measurements can be taken contemporaneously in the same place. Moreover, because they are small and don't use much power they can be used on buoys.

"Open-path sensors have the potential greatly to increase our understanding of the variability of air-sea carbon dioxide fluxes," said PhD student John Prytherch of the University of Southampton's School of Ocean and Earth Science at NOCS.

However, a long-standing concern has been that the values from open-path sensors do not tally with those from closed-path sensors, or with measurements made using other techniques.

"Other scientists have been sceptical about the reliability of carbon dioxide flux measurements taken at sea using open-path sensors," says Prytherch: "However, we now believe that we understand the reason for the discrepancy and that we can correct for it."

The problem turns out to be that the sensors are sensitive to humidity, meaning that fluctuations in the amount of water vapour in the sample air skew the carbon dioxide measurements. This is probably caused by salt particles on the sensor lens that absorb water.

Having identified the problem, Prytherch and his colleagues developed and rigorously tested a novel method for correcting the data for the cross-sensitivity to humidity.

Data were collected aboard the Norwegian weather ship Polarfront, equipped with a battery of instruments to measure wind speed, humidity and carbon dioxide. Even the motion of the ship was monitored.

The researchers noted that the carbon dioxide fluxes calculated from open-path sensor data were clearly too high and affected by humidity. They were also very variable, suggesting that the effect is caused by salt on the optics, which accumulate before being washed off by rain. Indeed, the researchers were able to mimic this effect in the laboratory.

However, after correction using their newly developed method, the calculated carbon dioxide fluxes were in line with previous studies that used different sensors or techniques.

"This robust method opens the way for widespread use of open-path sensors for air-sea carbon dioxide flux estimation," said Dr Margaret Yelland of NOCS: "This will greatly increase the information available on the transfer of carbon dioxide between the air and sea – information crucial for understanding how the ocean-atmosphere interaction impacts climate."

Heat and moisture from Himalayas could be a key cause of the South Asian monsoon

2010-01-20T01:36:00.000+05:30

Harvard climate scientists suggest that the Tibetan Plateau—thought to be the primary source of heat that drives the South Asian monsoon—may have far less of an effect than the Himalayas and other surrounding mountains. As the monsoon brings needed rainfall and water to billions of people each year, understanding its proper origin, especially in the context of global climate change, is crucial for the future sustainability of the region.

The researchers say the their findings, published in the January 14th issue of Nature, have broad implications for how the Asian climate may have responded to mountain uplift in the past, and for how it might respond to surface changes in the coming decades.

Often called the "roof of the world," the Tibetan Plateau is a vast area of 2.5 million square kilometers with an average elevation of more than 4,500 meters. Scientists have long theorized that the massive release of heat from the surface of the plateau—with air being heated to higher temperatures over the plateau than air at the same height over lower-level surfaces nearby—has been a major contributor to the strength of the monsoon.

"The South Asian monsoon supplies water to billions of people, many of whom live in developing nations and agricultural societies that are highly vulnerable to variations in this water supply," explains co-author Zhiming Kuang, Assistant Professor of Climate Science in Harvard's School of Engineering and Applied Sciences (SEAS) and Department of Earth and Planetary Sciences (EPS).

While the heating by the plateau does enhance rainfall along its southern edge, Kuang and his colleague William Boos, Daly Postdoctoral Fellow in EPS and an environmental fellow at the Harvard University Center for the Environment (HUCE), used an atmospheric circulation model to show that the large-scale South Asian summer monsoon circulation remains unaffected when the plateau is removed.

It turns out that the narrow geography of the Himalayas and other nearby mountain ranges can, in fact, produce an equally strong monsoon by insulating warm, moist air over continental India from the cold dry extratropics, the area between the subtropics and polar regions.

"Because heat from the plateau has been seen as the main contributor to the power of the monsoon, much attention has been given to changes in the plateau's albedo, or its reflectivity level of the sun's radiation," says Kuang.

For example, a decrease in snow cover over the Tibetan Plateau resulting from an increase in global temperatures can affect reflectivity, and hence, the level of heat. The revised theory, emphasizing the important role the mountains play in trapping warm and moist air, suggests that climate scientists should pay as much attention to changes over the Indian subcontinent due to, for example, land use.

How the region's natural environment is modified through activities such as building, mining, and agriculture, Zhang explains, can influence albedo and moisture, thus altering the temperature/humidity of the boundary layer air.

By considering the influence of both the plateau and the mountains on the strength of the monsoon, the Harvard researchers expect a clearer picture will emerge about the potential changes in the South Asian water supply in the coming decades.

"Ultimately, our revised view has implications for future projections of how the South Asian monsoon might be altered in a warmer world and can be used to infer aspects about the earth's climate history," says Boos.

New research sheds light on Earth’s coldest temperatures

2010-01-13T18:17:00.003+05:30

Results from the first detailed analysis of the lowest ever temperature recorded on the Earth’s surface can explain why it got so cold and how cold it could possibly get.

During the Antarctic winter of 1983 (July) temperatures plunged to a record-breaking −89.2°C at the Russian Vostok research station - more than 30°C lower than the average winter temperature. Until this study scientists did not understand why or how the temperature on the vast East Antarctic plateau could hit such an extreme low.

Scientists at British Antarctic Survey (BAS) and the Arctic and Antarctic Research Institute (AARI) in Russia found that for a period of 10 days the air flow that is normally fed from the Southern Ocean on to the high Antarctic plateau almost stopped. A flow of cold air circling Vostok was preventing the mixing of this warmer air from lower latitudes, isolating the station and causing near optimum cooling conditions. Adding to this was the absence of cloud cover and the layer of tiny particles of ice suspended in the air (known as diamond dust) allowing more heat from the ice surface to be lost to space.

The study was able to successfully simulate the rapid loss of heat over the 10 day period, which will aid the development of climate models used to predict the future evolution of the Antarctic climate system.

Lead author Professor John Turner at BAS says, "The majority of Antarctica has not yet warmed to the same extent as the Arctic, but over the next century we expect to see this situation change as the effects of greenhouse gas emissions have an impact. Distinguishing between natural variability and human induced changes to the Earth’s atmospheric climate is at the heart of our research and we wanted to understand why this ‘normal’ weather system was thrown out of balance so severely."

Prof Turner added, "Our findings indicate that this was a natural event, but this is an important reminder of just how extreme Earth’s natural events can be and that we must always consider the potential for such anomalies to occur. The East Antarctic plateau is remote from the ocean and extremely cold, and we believe that Vostok, at an altitude of 3,488m could get even colder, possibly reaching −96°C if an extreme isolation period such as this occurred over a longer period of time. Temperatures may even drop to −100°C at the higher Dome A - the summit of the East Antarctic Ice Cap. By appreciating that such possibilities can occur and in turn striving to understand the processes that cause them we are better equipped to make predictions for how the planet might react to future changes in polar atmospheric climate."

Second warmest year on record warrants action

2010-01-11T19:04:00.002+05:30

New figures showing that Australia experienced its second hottest year on record in 2009 should prompt politicians to take urgent action to cut carbon pollution.

The figures also show that average temperatures in 2009 were 0.9 degrees above the 1961-1990 average, and average temperatures for the whole decade were 0.48 degrees higher.

"The figures from Australia's Bureau of Meteorology are consistent with similar observations around the world which show unequivocally that our planet is warming," said Kellie Caught, WWF-Australia's Climate Policy Manager.

"The community, politicians, businesses and scientists accept that two degrees of warming represents dangerous climate change, and disturbingly we are already at least a quarter of the way there.

"The figures provide a sober reminder to our political and business leaders that the problem we face is not far away - it is real, and it is happening now," said Ms Caught.

"It's time to stop trying to pick holes in solid science. We must introduce carbon pollution laws now to prevent dangerous climate change."

WWF asks for all sides of politics to support the proposed CPRS as an essential step in reducing Australia's carbon pollution.

"The overwhelming majority of developed countries already have, or are in the process of introducing, an emissions trading scheme. Australia will be left behind to the detriment of our economy and environment," said Ms Caught.

"Australia urgently needs to reduce carbon pollution by at least 25 per cent before 2020. This is the only way we will help keep global temperatures to a safe increase.

"We have the technology and an affordable policy solution to reduce carbon pollution, we need to ignore the naysayers and get on with the job."

Bering Strait influenced ice age climate patterns worldwide

2010-01-11T17:10:00.000+05:30

Closed Bering Strait and global climate. Scientists are unraveling a chain of events that led to large-scale warmings and coolings across the Northern Hemisphere during past ice ages. As ice sheets expanded, water levels dropped in the narrow Bering Strait (left) and cut off the flow of relatively fresh water from the northern Pacific through the Arctic into the saltier Atlantic. This altered ocean currents, increasing the flow of Atlantic water northward from the tropics and producing warming in the north Atlantic (right, shown in dark red) that melted ice sheets and affected climate patterns and sea levels across much of the world. (Courtesy Nature, modified by UCAR.)In a vivid example of how a small geographic feature can have far-reaching impacts on climate, new research shows that water levels in the Bering Strait helped drive global climate patterns during ice age episodes dating back more than 100,000 years.

The international study, led by scientists at the National Center for Atmospheric Research (NCAR), found that the repeated opening and closing of the narrow strait due to fluctuating sea levels affected currents that transported heat and salinity in the Atlantic and Pacific oceans. As a result, summer temperatures in parts of North America and Greenland oscillated between warmer and colder phases, causing ice sheets to alternate between expansion and retreat and affecting sea levels worldwide.
While the findings do not directly bear on current global warming, they highlight the complexity of Earth's climate system and the fact that seemingly insignificant changes can lead to dramatic tipping points for climate patterns, especially in and around the Arctic.

"The global climate is sensitive to impacts that may seem minor," says NCAR scientist Aixue Hu, the lead author. "Even small processes, if they are in the right location, can amplify changes in climate around the world."

The study is being published this week in Nature Geoscience. Funded by the Department of Energy and the National Science Foundation, NCAR's sponsor, it used the latest generation of supercomputers to study past climate at a level of detail that would have been impossible just a few years ago.

New clues to an ice age mystery

Hu and his colleagues set out to solve a key mystery of the last glacial period: Why, starting about 116,000 years ago, did northern ice sheets repeatedly advance and retreat for about the next 70,000 years? The enormous ice sheets held so much water that sea levels rose and dropped by as much as about 100 feet (30 meters) during these intervals.

In other cases, scientists have associated such major oscillations in climate with fluctuations in Earth's orbit around the Sun. But in the time period that the research team looked at, the orbital pattern did not correspond with the geologic movement of the ice sheets and associated sea level changes.

The study team considered an alternative possibility: that changes in the Bering Strait, the main gateway in the Northern Hemisphere between the Atlantic and Pacific oceans, might have affected ocean currents across much of the globe. Although small-the strait is currently about 50 miles (80 kilometers) wide between Russia and the westernmost islands of Alaska-it allows water to circulate from the relatively fresh north Pacific to the saltier north Atlantic via the Arctic Ocean. This flow is instrumental to regulating the strength of a current known as the meridional overturning circulation, a key driver of heat from the tropics to the poles.

Supercomputers reveal a pattern of warming and cooling

Using the NCAR-based Community Climate System Model, a powerful computer tool for studying worldwide climate, the researchers compared the responses of ice age climate to conditions in the Bering Strait. They ran the model on new supercomputers at NCAR and the Department of Energy's Oak Ridge National Laboratory, enabling them to focus on smaller-scale geographic features that, until recently, could not be captured in long-term simulations of global climate.

The simulations accounted for the changes in sea level, revealing a recurring pattern-each time playing out over several thousand years-in which the reopening and closing of the strait had a far-reaching impact on ocean currents and ice sheets.

* As the climate cooled because of changes in Earth's orbit, northern ice sheets expanded. This caused sea levels to drop worldwide, forming a land bridge from Asia to North America and nearly closing the Bering Strait.

* With the flow of relatively fresh water from the Pacific to the Atlantic choked off, the Atlantic grew more saline. The saltier and heavier water led to an intensification of the Atlantic's meridional overturning circulation, a current of rising and sinking water that, like a conveyor belt, pumps warmer water northward from the tropics.

* This circulation warmed Greenland and parts of North America by about 3 degrees Fahrenheit (1.5 degrees Celsius)-enough to reverse the advance of ice sheets in those regions and reduce their height by almost 400 feet (112 meters) every thousand years. Although the Pacific cooled by an equivalent amount, it did not have vast ice sheets that could be affected by the change in climate.

* Over thousands of years, the Greenland and North American ice sheets melted enough to raise sea levels and reopen the Bering Strait.

* The new inflow of fresher water from the Pacific weakened the meridional overturning circulation, allowing North America and Greenland to cool over time. The ice sheets resumed their advance, sea levels dropped, the Bering Strait again mostly closed, and the entire cycle was repeated.

The combination of the ocean circulation and the size of the ice sheets-which exerted a cooling effect by reflecting sunlight back into space-affected climate throughout the world. The computer simulations showed that North America and Eurasia warmed significantly during the times when the Bering Strait was open, with the tropical and subtropical Indian and Pacific Oceans, as well as Antarctica, warming slightly.

Learning from the past

The pattern was finally broken about 34,000 years ago, the point in Earth's 95,000-year orbital cycle at which the planet was so far from the Sun at certain times of year that the ice sheets continued to grow even when the Bering Strait closed. When the orbital cycle brought Earth closer to the Sun in the northern winter, the ice sheets retreated sufficiently about 10,000 years ago to reopen the strait. This helped lead to a relatively stable climate, nurturing the rise of civilization.

"This kind of study is critical for teasing out the nuances of our climate system," says NCAR scientist Gerald Meehl, a co-author of the paper. "If we can improve our understanding of the forces that affected climate in the past, we can better anticipate how our climate may change in the future."

In addition to NCAR, the study team included researchers from the National Center for Scientific Research (CNRS) in France, University of Colorado in Boulder, Catholic University of Louvain in Belgium, Australian National University, and Harvard University.

Coral can recover from climate change damage

2010-01-10T03:47:00.000+05:30

A study by the University of Exeter provides the first evidence that coral reefs can recover from the devastating effects of climate change. Published Monday 11 January in the journal PLOS One, the research shows for the first time that coral reefs located in marine reserves can recover from the impacts of global warming.

Scientists and environmentalists have warned that coral reefs may not be able to recover from the damage caused by climate change and that these unique environments could soon be lost forever. Now, this research adds weight to the argument that reducing levels of fishing is a viable way of protecting the world's most delicate aquatic ecosystems.

Increases in ocean surface water temperatures subject coral reefs to stresses that lead quickly to mass bleaching. The problem is intensified by ocean acidification, which is also caused by increased CO2. This decreases the ability of corals to produce calcium carbonate (chalk), which is the material that reefs are made of.

Approximately 2% of the world's coral reefs are located within marine reserves, areas of the sea that are protected against potentially-damaging human activity, like dredging and fishing.

The researchers conducted surveys of ten sites inside and outside marine reserves of the Bahamas over 2.5 years. These reefs have been severely damaged by bleaching and then by hurricane Frances in the summer of 2004. At the beginning of the study, the reefs had an average of 7% coral cover. By the end of the project, coral cover in marine protected areas had increased by an average of 19%, while reefs in non-reserve sites showed no recovery.

Professor Peter Mumby of the University of Exeter said: "Coral reefs are the largest living structures on Earth and are home to the highest biodiversity on the planet. As a result of climate change, the environment that has enabled coral reefs to thrive for hundreds of thousands of years is changing too quickly for reefs to adapt.

"In order to protect reefs in the long-term we need radical action to reduce CO2 emissions. However, our research shows that local action to reduce the effects of fishing can contribute meaningfully to the fate of reefs. The reserve allowed the number of parrotfishes to increase and because parrotfish eat seaweeds, the corals could grow freely without being swamped by weeds. As a result, reefs inside the park were showing recovery whereas those with more seaweed were not. This sort of evidence may help persuade governments to reduce the fishing of key herbivores like parrotfishes and help reefs cope with the inevitable threats posed by climate change".

Echinoderms contribute to global carbon sink

2010-01-10T03:46:00.000+05:30

The impact on levels of carbon dioxide in the Earth's atmosphere by the decaying remains of a group of marine creatures that includes starfish and sea urchin has been significantly underestimated.

"Climate models must take this carbon sink into account," says Mario Lebrato, lead author of the study. The work was done when he was at the National Oceanography Centre, Southampton (NOCS) and affiliated with the University of Southampton's School of Ocean and Earth Science (SOES); he is now at the Leibniz Institute of Marine Science in Germany.

Globally, the seabed habitats occupy more than 300 million million square metres, from the intertidal flats and pools to the mightiest deep-sea trenches at 11,000 meters. The benthos – the animals living on and in the sediments – populate this vast ecosystem.

Calcifying organisms incorporate carbon directly from the seawater into their skeletons in the form of inorganic minerals such as calcium carbonate. This means that their bodies contain a substantial amount of inorganic carbon. When they die and sink, some of the inorganic carbon is remineralised, and much of it becomes buried in sediments, where it remains locked up indefinitely.

Lebrato and his colleagues provide the first estimation of the contributions of starfish, sea urchins, brittle stars, sea cucumbers and sea lilies – all kinds of echinoderm – to the calcium carbonate budget at the seabed. They estimate that the global production from all echinoderms is over a tenth (0.1) of a gigatonne of carbon per year – that is, more than a hundred thousand million kilograms.

This is less than the total biological production in the main water column, or pelagic zone, which scientists believe to be between around 0.6 and 1.8 gigatonnes of carbon per year. But echinoderms apparently deliver more carbon to the sediments than do forams, for example. These microscopic animals live in vast numbers in the oceans and are traditionally regarded along with coccolithophores (single-celled marine plants surrounded by calcium carbonate plates) as one of the biggest contributors to the flux of calcium carbonate from the sunlit surface waters to the ocean's interior – the so-called 'biological carbon pump'.

"Our research highlights the poor understanding of large-scale carbon processes associated with calcifying animals such as echinoderms and tackles some of the uncertainties in the oceanic calcium carbonate budget," says Lebrato: "The realisation that these creatures represent such a significant part of the ocean carbon sink needs to be taken into account in computer models of the biological pump and its effect on global climate."

There is a worry that ocean acidification due to increased carbon dioxide emissions from the burning of fossil fuels could reduce the amount of calcium carbonate incorporated into the skeletons of echinoderms and other calcifying organisms.

However, different echinoderm species respond to ocean acidification in different ways, and the effects of rising temperatures can be as significant as those of rising carbon dioxide. How this will affect the global carbon sink remains to be established.

Lebrato concludes: "The scientific community needs to reconsider the role of benthic processes in the marine calcium carbonate cycle. This is a crucial but understudied compartment of the global marine carbon cycle, which has been of key importance throughout Earth history and it is still at present."

How plants 'feel' the temperature rise

2010-01-10T03:45:00.000+05:30

Plants are incredibly temperature sensitive and can perceive changes of as little as one degree Celsius. A report in the January 8th issue of the journal Cell shows how they not only 'feel' the temperature rise, but also coordinate an appropriate response - activating hundreds of genes and deactivating others; it turns out it's all about the way that their DNA is packaged.

The findings may help to explain how plants will respond in the face of climate change and offer scientists new leads in the quest to create crop plants better able to withstand high temperature stress, the researchers say.

"We've uncovered a master regulator of the entire temperature transcriptome," said Philip Wigge of John Innes Centre in the United Kingdom in reference to the thousands of genes that are differentially activated under warmer versus cooler conditions.

Using the model plant Arabidopsis thaliana the researchers show that a key ingredient for plants' temperature sensing ability is a specialized histone protein, dubbed H2A.Z, that wraps DNA into a more tightly packed structure known as a nucleosome. Wigge likens nucleosomes to compact balls of string. As temperatures rise, H2A.Z histones allow DNA to progressively unwrap, leading nucleosomes to loosen up, they show.

"When it gets warmer, the DNA unwraps," he said, which allows some genes to switch on and others to switch off. They aren't yet sure exactly how all that happens, but Wigge suspects the altered nucleosome structure gives access to sites on the DNA where activators of some genes can bind along with repressors of other genes.

"In addition to H2A.Z containing nucleosomes having more tightly wrapped DNA, our results suggest that the degree of unwrapping may also be responsive to temperature," the researchers wrote. "This result suggests a direct mechanism by which temperature may influence gene expression, since it has been shown that RNA Pol II [the enzyme responsible for transcribing DNA into messenger RNA] does not actively invade nucleosomes, but waits for local unwrapping of DNA from nucleosomes before extending transcription. In this way, genes with a paused RNA Pol II will show increased transcription with greater temperature as local unwrapping is increased." The basic discovery could ultimately prove to have important implications for world food security, the researchers said.

As the number of people and affluence around the world continues to grow, "it is projected that world agriculture will have to increase yields by 70 to 100 percent in the next 100 years," Wigge said. "Under climate change it will be challenging simply to maintain present yields, let alone increase them." Crops such as wheat are particularly vulnerable to very hot and dry summers, he added, as evidenced by the fact that wheat reserves recently fell to their lowest level in 30 years.

He says the new understanding of plants' temperature sensitivity may prove to be critical for breeding more temperature-resistant crops. His team plans to explore this possibility by studying the role of these H2A.Z histones in a model plant that is more closely related to crops.

"We'd like to engineer a plant where we can control the histones in particular tissues such that it is selectively 'blind' to different temperatures," Wigge said. "Obviously you can't make a completely temperature-proof plant, but there is a lot of scope to develop crops that are more resilient to the high temperatures we are increasingly going to experience."

Arctic could face warmer and ice-free conditions

2009-12-30T23:28:00.002+05:30

There is increased evidence that the Arctic could face seasonally ice-free conditions and much warmer temperatures in the future.

Scientists documented evidence that the Arctic Ocean and Nordic Seas were too warm to support summer sea ice during the mid-Pliocene warm period (3.3 to 3 million years ago). This period is characterized by warm temperatures similar to those projected for the end of this century, and is used as an analogue to understand future conditions.

The U.S. Geological Survey found that summer sea-surface temperatures in the Arctic were between 10 to 18^°C during the mid-Pliocene, while current temperatures are around or below 0^°C.

Examining past climate conditions allows for a true understanding of how Earth's climate system really functions. USGS research on the mid-Pliocene is the most comprehensive global reconstruction for any warm period. This will help refine climate models, which currently underestimate the rate of sea ice loss in the Arctic.

Loss of sea ice could have varied and extensive consequences, such as contributions to continued Arctic warming, accelerated coastal erosion due to increased wave activity, impacts to large predators (polar bears and seals) that depend on sea ice cover, intensified mid-latitude storm tracks and increased winter precipitation in western and southern Europe, and less rainfall in the American west.

"In looking back 3 million years, we see a very different pattern of heat distribution than today with much warmer waters in the high latitudes," said USGS scientist Marci Robinson. "The lack of summer sea ice during the mid-Pliocene suggests that the record-setting melting of Arctic sea ice over the past few years could be an early warning of more significant changes to come."

Global average surface temperatures during the mid-Pliocene were about 3^°C greater than today and within the range projected for the 21st century by the Intergovernmental Panel on Climate Change.

Scientists studied conditions during the mid-Pliocene by analysing fossils dated back to this time period. The USGS led this research through the Pliocene Research, Interpretation and Synoptic Mapping group. The primary collaborators in PRISM are Columbia University, Brown University, University of Leeds, University of Bristol, the British Geological Survey and the British Antarctic Survey.

African leaf-eating primates are ‘likely to be wiped out’ by climate change

2009-12-29T13:18:00.000+05:30

Monkey species will become ‘increasingly at risk of extinction’ because of global warming, according to new research, published this week. It reveals that populations of monkeys and apes in Africa that depend largely on a diet of leaves may be wiped out by a rise in annual temperatures of two degrees Celsius. The study by researchers from Bournemouth, Roehampton and Oxford Universities suggests that the species most at risk are the already endangered gorillas and colobine monkeys.

The paper, published online by Animal Behaviour, pinpoints which species are most threatened by climate change in a series of new global maps. They show current and predicted distribution patterns of primates, comparing the populations according to their diet and the amount of enforced rest they are predicted to need.

They warn that Old World monkey populations in Africa will be hardest hit even by a very modest two degrees Celsius increase in global mean temperature, especially those whose diets are mainly leaf-based such as the beautiful colobine monkeys. In contrast, New World monkeys in South America will be virtually unaffected by a rise of two degrees in mean temperatures. However, even the South American species will begin to suffer if temperatures rise as much as four degrees Celsius (the currently predicted most extreme value) because suitable habitats will then become increasingly fragmented and small fragmented populations are more liable to chance risks of extinction.

These predictions are based on analyses of the ecological constraints that determine how much time animals are forced to rest. The researchers found that animals that have forced rest have less time to forage for food or engage in other biologically essential activities, such as forming friendships. Although most primates have adaptations that help them cope with the heat, they head for shelter and rest when the sun gets too hot. The researchers show that resting time is influenced by three main factors, the percentage of leaves in the animals’ diet, temperature variation and mean annual temperature. When these three effects come together, susceptible species will be unable to cope and populations will go extinct.

The researchers used climate models coupled with an analysis of quantitative data on the behaviour, diet and group size of different primate species across the world. African monkeys and apes that have a high percentage of leaves in their diet are geographically more restricted even now, being confined to a relatively narrow region around the equator. However, fruit-eating species like the baboons and guenon monkeys of Africa typically have a much wider latitudinal range and can cope with a wider range of climatic conditions. This ecological separation between fruit- and leaf-eating species is much less obvious in the Americas, and so these species will be much less badly affected by climate warming. The contrast between the continents may be due to the fact that African fruit-eating species may have developed a particular ecological adaptation to more challenging habitats than those encountered by species in South America.

Lead author Dr Amanda Korstjens, from Bournemouth University, said, "The possibility that enforced resting time might have so strong an effect on where on the map a major mammal group is likely to survive has not previously been appreciated. This study suggests that the amount of time available for monkeys and apes to gather food and socialise may be a key factor when looking at possible effects of climate change on animal distribution patterns in the past and in the future."

Professor Robin Dunbar, from the Institute of Cognitive and Evolutionary Anthropology at the University of Oxford, said, ‘We often worry about deforestation and hunting as the two main factors threatening the extinction of primate populations, but these results suggest that even if we find ways to solve these problems, it may not save some species of monkeys and apes from extinction. Instead, we perhaps should worry about ensuring that we provide these species with habitats that are more in tune with their capacities to cope with climate change.’

Dr Julia Lehmann, from Roehampton University, said, "At overall temperature increases of two and four degrees Celsius, the distribution of habitat suitable for species that eat a lot of leaves will be greatly reduced. The distribution of suitable habitat would become progressively restricted and increasingly fragmented. The scale of the effect is sufficiently large that the implications for the survival of the dietetically more specialised primates are worrying."