[naturenews] from [nature.com]
[naturenews]
Published online 29 September 2009 | Nature | doi:10.1038/news.2009.959
News
Climate sizzle could come soon
UK researchers predict 4 °C rise within decades.
By Anna Barnett
{{If global temperatures rise by 4 °C many countries could see rainfall drop by a fifth.}
Jodie Coston / Getty}}
The planet could warm by 4 °C as early as 2060 if greenhouse-gas emissions are not curbed quickly and dramatically, according to a UK government-backed study.
The research, commissioned by the UK Department of Energy and Climate Change in London from the Met Office Hadley Centre in Exeter, looks in detail at the future high-emissions scenario that was considered the worst case in the 2007 report from the Intergovernmental Panel on Climate Change (IPCC).
Much analysis and policy debate has focused on avoiding global warming of more than 2 °C above pre-industrial temperatures — widely considered to be the threshold for dangerous climate change. But emissions have continued to rise rapidly and the latest findings on the carbon cycle have strengthened the view that in future, less of our CO2 emissions will be absorbed by natural sinks. So a much greater temperature rise is increasingly plausible, says Richard Betts, who presented the study at the conference 4 Degrees and Beyond in Oxford, UK, on 28 September.
"Now we know that emissions are at the upper end of what the IPCC projected a decade ago, it justifies taking the higher-emissions scenario more seriously," says Betts. Moreover, he says, evidence is accumulating that warming will weaken natural carbon sinks that so far have been taking up 50% of the greenhouse gases produced from the burning of fossil fuels, speeding up warming even further.
Extreme scenario?
Betts's group applied a complex climate model to the IPCC's highest-emissions scenario that incorporated the effects of weakening sinks. Depending on how much the sinks weaken — a key source of uncertainty — they found that temperatures of 4 °C higher than pre-industrial levels would probably be reached in the 2070s, and perhaps by 2060.
In climate simulations where average global temperature rises 4 °C or more, oceans warm less than that average and land areas more — by 7 °C in many areas, Betts reports. Temperatures could shoot up by up to 10 °C in western and southern Africa and by that much or more in the Arctic, and decreases in rainfall of 20% or more would be widespread in parts of Africa, Australia, the Mediterranean and Central America.
"It's an extreme scenario, but one that is plausible," says Betts. "When millions of people's lives are at stake, it's worthwhile thinking about extreme, plausible scenarios."
To avoid a rise of 4 °C, emissions must peak and then steeply decline within the next 30 years, says Betts. To stay under 2 °C, that needs to happen in a decade. But even if ambitious action is agreed at this year's United Nations climate conference in Copenhagen, he says, it will take years to implement. This puts policy-makers between a rock and a hard place, says Kevin Anderson of the Tyndall Centre for Climate Change Research in Norwich, UK. "Mitigating for 2 °C is much more challenging than was previously thought, but adapting to 4 °C is also extremely challenging," Anderson says. "There is no easy way out."
[naturenews]
Published online 29 September 2009 | Nature | doi:10.1038/461578b
News
Experts draw up ocean-drilling wish list
Researchers seek deeper understanding of crust formation.
By Quirin Schiermeier
BREMEN
{{The United States' research vessel the JOIDES Resolution is equipped to drill down 2 kilometres into the seabed.}
J. Beck/IODP}}
Earth scientists have laid the groundwork for the future of ocean drilling. More than 500 scientists — almost twice as many as organizers had initially expected — gathered last week in Bremen, Germany, to discuss priorities and research goals for the second phase of the Integrated Ocean Drilling Program (IODP), which is expected to begin in late 2013.
Since ocean drilling began in the 1960s, sediment and rock cores retrieved from the seabed have provided information about everything from plate tectonics to Earth's climate history. Much more remains to be discovered, scientists said at the meeting.
"We're not done," says Alan Mix, a marine geologist at Oregon State University in Corvallis. "Actually, we ain't seen nothing yet."
Researchers have generated a detailed wish list for new ocean-drilling projects, which will be boiled down into a science plan for the 2013–23 period by a group yet to be appointed. The finalized science plan will then be forwarded to funding agencies in Japan, Europe and North America, which currently support the IODP to the tune of around US$200 million per year.
Mix says that targets might include the role of greenhouse gases in transitions between cold and warm climates, and the magnitude, speed and locations of resulting sea-level changes. A more ambitious project would be to relaunch the effort to drill through Earth's crust and into its mantle. A 1960s attempt to drill through the sea floor into this boundary, known as the Mohorovičić discontinuity, or 'Moho', failed.
The Japanese IODP vessel, the Chikyu, is already outfitted with technology to drill down some 7,000 metres into the crust, and there are plans to refit the vessel over the next three years with drilling and core-recovery technology to allow it to drill even deeper.
"Japan will lead the Moho project," says Asahiko Taira, the Yokohama-based executive director of the Japan Agency for Marine–Earth Science and Technology, which oversees Japan's ocean-drilling operations. "It's a classic geological quest, and definitely one of our prime targets."
"The journey down is equally important to the things we may find at the bottom," adds Benoît Ildefonse, a geologist at France's National Centre for Scientific Research (CNRS) based in Montpellier, France. "Recovering rocks from near Moho will, for the first time, allow us to test our ideas and models about how the crust forms."
The deepest sea-floor holes drilled so far include a 2,111-metre-deep hole drilled during the 1970s and 1980s off Nicaragua, and a 1,500-metre-deep hole drilled in 2005 in the Cocos plate in the eastern Pacific Ocean. The latter, performed by the US vessel JOIDES Resolution, was the first continuous retrieval of core from Earth's upper crust. Following a $130-million refurbishment, the 30-year-old ship is now capable of drilling 2,000 metres into the sea floor in waters as deep as 7,000 metres.
IODP leaders say they are increasingly aware of the need to explain the societal relevance of their work. "We need to explain very well why what we are doing matters," says Catherine Mével, director of the European Consortium for Ocean Research Drilling, which coordinates the activities of 16 European IODP members and Canada. "We haven't always been able to make this clear enough in the past."
Meanwhile, China — an associate IODP member alongside South Korea, Taiwan, India, Australia and New Zealand — has announced plans to build a deep-sea drilling vessel of its own.
"The small Chinese deep-sea research community is rapidly growing in numbers, and our formerly reluctant government is increasingly convinced about the significance of ocean drilling," says Wang Pinxian, a marine geologist at Tongji University in Shanghai and vice-chair of the Chinese IODP science committee.
As an associate member with limited ship time and managerial rights, China pays the reduced IODP membership of US$1 million. The Chinese government and the Chinese Academy of Sciences are currently discussing whether China should apply for full membership beyond 2013, for which it would need to pay around $6 million per year, says Wang.
IODP rules and overall programme architecture are unlikely to undergo any substantial changes after 2013, says Rodey Batiza, section head of marine geosciences at the US National Science Foundation in Arlington, Virgina. New members will be welcome to join, but membership will not be linked to specific national drilling preferences, he says.
"We'd like to seamlessly continue drilling after 2013 with a programme designed to deliver the best science at the lowest cost," he says. "We do already have some very exciting questions that we can ask, and perhaps answer, in the next ten years."
[naturenews]
Published online 29 September 2009 | Nature | doi:10.1038/news.2009.959
News
Climate sizzle could come soon
UK researchers predict 4 °C rise within decades.
By Anna Barnett
{{If global temperatures rise by 4 °C many countries could see rainfall drop by a fifth.}
Jodie Coston / Getty}}
The planet could warm by 4 °C as early as 2060 if greenhouse-gas emissions are not curbed quickly and dramatically, according to a UK government-backed study.
The research, commissioned by the UK Department of Energy and Climate Change in London from the Met Office Hadley Centre in Exeter, looks in detail at the future high-emissions scenario that was considered the worst case in the 2007 report from the Intergovernmental Panel on Climate Change (IPCC).
Much analysis and policy debate has focused on avoiding global warming of more than 2 °C above pre-industrial temperatures — widely considered to be the threshold for dangerous climate change. But emissions have continued to rise rapidly and the latest findings on the carbon cycle have strengthened the view that in future, less of our CO2 emissions will be absorbed by natural sinks. So a much greater temperature rise is increasingly plausible, says Richard Betts, who presented the study at the conference 4 Degrees and Beyond in Oxford, UK, on 28 September.
"Now we know that emissions are at the upper end of what the IPCC projected a decade ago, it justifies taking the higher-emissions scenario more seriously," says Betts. Moreover, he says, evidence is accumulating that warming will weaken natural carbon sinks that so far have been taking up 50% of the greenhouse gases produced from the burning of fossil fuels, speeding up warming even further.
Extreme scenario?
Betts's group applied a complex climate model to the IPCC's highest-emissions scenario that incorporated the effects of weakening sinks. Depending on how much the sinks weaken — a key source of uncertainty — they found that temperatures of 4 °C higher than pre-industrial levels would probably be reached in the 2070s, and perhaps by 2060.
In climate simulations where average global temperature rises 4 °C or more, oceans warm less than that average and land areas more — by 7 °C in many areas, Betts reports. Temperatures could shoot up by up to 10 °C in western and southern Africa and by that much or more in the Arctic, and decreases in rainfall of 20% or more would be widespread in parts of Africa, Australia, the Mediterranean and Central America.
"It's an extreme scenario, but one that is plausible," says Betts. "When millions of people's lives are at stake, it's worthwhile thinking about extreme, plausible scenarios."
To avoid a rise of 4 °C, emissions must peak and then steeply decline within the next 30 years, says Betts. To stay under 2 °C, that needs to happen in a decade. But even if ambitious action is agreed at this year's United Nations climate conference in Copenhagen, he says, it will take years to implement. This puts policy-makers between a rock and a hard place, says Kevin Anderson of the Tyndall Centre for Climate Change Research in Norwich, UK. "Mitigating for 2 °C is much more challenging than was previously thought, but adapting to 4 °C is also extremely challenging," Anderson says. "There is no easy way out."
[naturenews]
Published online 29 September 2009 | Nature | doi:10.1038/461578b
News
Experts draw up ocean-drilling wish list
Researchers seek deeper understanding of crust formation.
By Quirin Schiermeier
BREMEN
{{The United States' research vessel the JOIDES Resolution is equipped to drill down 2 kilometres into the seabed.}
J. Beck/IODP}}
Earth scientists have laid the groundwork for the future of ocean drilling. More than 500 scientists — almost twice as many as organizers had initially expected — gathered last week in Bremen, Germany, to discuss priorities and research goals for the second phase of the Integrated Ocean Drilling Program (IODP), which is expected to begin in late 2013.
Since ocean drilling began in the 1960s, sediment and rock cores retrieved from the seabed have provided information about everything from plate tectonics to Earth's climate history. Much more remains to be discovered, scientists said at the meeting.
"We're not done," says Alan Mix, a marine geologist at Oregon State University in Corvallis. "Actually, we ain't seen nothing yet."
Researchers have generated a detailed wish list for new ocean-drilling projects, which will be boiled down into a science plan for the 2013–23 period by a group yet to be appointed. The finalized science plan will then be forwarded to funding agencies in Japan, Europe and North America, which currently support the IODP to the tune of around US$200 million per year.
Mix says that targets might include the role of greenhouse gases in transitions between cold and warm climates, and the magnitude, speed and locations of resulting sea-level changes. A more ambitious project would be to relaunch the effort to drill through Earth's crust and into its mantle. A 1960s attempt to drill through the sea floor into this boundary, known as the Mohorovičić discontinuity, or 'Moho', failed.
The Japanese IODP vessel, the Chikyu, is already outfitted with technology to drill down some 7,000 metres into the crust, and there are plans to refit the vessel over the next three years with drilling and core-recovery technology to allow it to drill even deeper.
"Japan will lead the Moho project," says Asahiko Taira, the Yokohama-based executive director of the Japan Agency for Marine–Earth Science and Technology, which oversees Japan's ocean-drilling operations. "It's a classic geological quest, and definitely one of our prime targets."
"The journey down is equally important to the things we may find at the bottom," adds Benoît Ildefonse, a geologist at France's National Centre for Scientific Research (CNRS) based in Montpellier, France. "Recovering rocks from near Moho will, for the first time, allow us to test our ideas and models about how the crust forms."
The deepest sea-floor holes drilled so far include a 2,111-metre-deep hole drilled during the 1970s and 1980s off Nicaragua, and a 1,500-metre-deep hole drilled in 2005 in the Cocos plate in the eastern Pacific Ocean. The latter, performed by the US vessel JOIDES Resolution, was the first continuous retrieval of core from Earth's upper crust. Following a $130-million refurbishment, the 30-year-old ship is now capable of drilling 2,000 metres into the sea floor in waters as deep as 7,000 metres.
IODP leaders say they are increasingly aware of the need to explain the societal relevance of their work. "We need to explain very well why what we are doing matters," says Catherine Mével, director of the European Consortium for Ocean Research Drilling, which coordinates the activities of 16 European IODP members and Canada. "We haven't always been able to make this clear enough in the past."
Meanwhile, China — an associate IODP member alongside South Korea, Taiwan, India, Australia and New Zealand — has announced plans to build a deep-sea drilling vessel of its own.
"The small Chinese deep-sea research community is rapidly growing in numbers, and our formerly reluctant government is increasingly convinced about the significance of ocean drilling," says Wang Pinxian, a marine geologist at Tongji University in Shanghai and vice-chair of the Chinese IODP science committee.
As an associate member with limited ship time and managerial rights, China pays the reduced IODP membership of US$1 million. The Chinese government and the Chinese Academy of Sciences are currently discussing whether China should apply for full membership beyond 2013, for which it would need to pay around $6 million per year, says Wang.
IODP rules and overall programme architecture are unlikely to undergo any substantial changes after 2013, says Rodey Batiza, section head of marine geosciences at the US National Science Foundation in Arlington, Virgina. New members will be welcome to join, but membership will not be linked to specific national drilling preferences, he says.
"We'd like to seamlessly continue drilling after 2013 with a programme designed to deliver the best science at the lowest cost," he says. "We do already have some very exciting questions that we can ask, and perhaps answer, in the next ten years."
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