Climate Feedback

"We're slogging ahead...I'm not going to kid anybody; I don't think it's easy. But I do think that we will get there."
After two days of high-level talks in Washington, US climate envoy Todd Stern predicts an American-Chinese climate agreement will be forged before Copenhagen.

Jellyfish study raises "bizarre ancillary questions" for climate modellers
If swimming jellyfish significantly affect ocean mixing, as a new study suggests, "the modelling community is going to have to pay attention", comments MIT's Carl Wunsch.

"To claim that global temperatures have cooled since 1998 and therefore that man-made climate change isn't happening is a bit like saying spring has gone away when you have a mild week after a scorching Easter."
Bob Henson of NCAR says this perennial skeptics' argument is refuted in a forthcoming paper by US Navy and NASA scientists (Geophysical Research Letters subscription required).

"If employees are on the road 20 percent less, and office buildings are only powered four days a week, the energy savings ... would be enormous."
John Langmaid is organizing the Connecticut Law Review's upcoming symposium on the benefits of taking Friday off. The state of Utah has estimated it could save 12,000 tonnes of CO2 emissions per year by putting its employees on the 4-day, 40-hour workweek.

Posted by Olive Heffernan on July 31, 2009
Categories: In the News | Permalink | Comments (0) | TrackBacks (0)

Sure, accidentally heating the planet has been pretty easy. But try intentionally heating a plot of forest, and you get a whole other story.

In this week’s Nature, we take a brief look at a series of new experiments to test how warmer temperatures will change the composition of forests in different regions of the United States. Will forests begin to sprout above the tree line in the Colorado Rocky Mountains? Will oaks sweep northwards, deeper into the boreal forests of the northern United States and Canada?

Unfortunately, reliably and evenly heating a stand of grown trees to a set number of degrees above ambient temperature turns out to be pretty difficult to do. For now, these projects are limited to seedlings which will outgrow their heaters within a few years. Such studies are valuable in their own right – seedlings lack the extensive root networks that could help them survive a hot, dry summer, and are therefore a weak link in the chain of forest succession. Still, wouldn’t it be great if we could see the effects of climate change on the grown-ups, too?

Continue reading "How to heat a forest… or at least, a part of one" »

Posted by Anna Barnett on July 30, 2009
Categories: Biodiversity and Ecology, Heidi Ledford | Permalink | Comments (1) | TrackBacks (0)

Northern peatlands, typical for subarctic Scandinavia and Russia, contain one third of the world’s soil organic carbon. How much extra carbon these soils will release to the atmosphere, through accelerated respiration in a warmer climate, has been pretty much guesswork. Data from an eight-year in situ experiment carried out in Sweden now suggest that even modest warming will release enough extra carbon to effectively equalize the European Union’s emissions reductions achieved under the Kyoto Protocol.

Ellen Dorrepaal and her colleagues studied ecosystem response to climate warming at a test site near the Swedish Abisko scientific research station, some 200 kilometres inside the Arctic Circle. In a paper in Nature today (subscription required) they report that warming accelerated the respiration of carbon in peat overlaying the permafrost by almost 70 % - much more than previously thought. Here's an editor's summary.

Extrapolated to the total northern peatland area, the results suggest that climate warming of 1 degree Celsius over the next decade might lead to a global increase in respiration of 38-100 million tonnes of carbon per year. For comparison: The EU’s Kyoto target is to reduce emissions by 92 million tonnes of carbon per year.

The researchers stress that the effect is likely to last: “In contrast to long-term studies in forest, meadow and tundra ecosystems, the warming effect did not decline towards the eighth year of the study,” they write.

The net effect of warming on northern carbon reservoirs includes possible gains from increased plant growth. But in Arctic ecosystems dominated by peat and moss, there are too few productive woody shrubs growing to offset the warming effect on soils.

Quirin Schiermeier

Image: Subarctic peatland in Abisko, North Sweden where the consequences for CO2-respiration rates were investigated. Credit: Ellen Dorrepaal

Posted by Quirin Schiermeier on July 30, 2009
Categories: Categories, Biosphere feedbacks, Climate Science, GHG emissions, Quirin Schiermeier, Topics, Uncertainty | Permalink | Comments (3) | TrackBacks (0)

In the latest salvo of the scientific debate over future sea level rise, a new report counters claims that rapidly swelling seas will soak estimates published by the UN climate planel in 2007.

A major “it’s worse than we thought” story out of March’s Copenhagen Climate Congress, for example, was that sea level could climb more than a metre by 2100 - seemingly far worse than the rise of up to 59 centimetres indicated in the 2007 report from the Intergivernmental Panel on Climate Change (IPCC). This was in fact something of a straw-man comparison, since the IPCC total explicitly excluded the impacts of accelerated glacier melt, and the new studies were attempting to add these impacts in.

But the latest study suggests that even considering glacier effects, the 2100 rise is likely to be well under a metre. A trio of researchers - Mark Siddall of Columbia University in New York, Thomas Stocker of the University of Bern (current co-chair of IPCC Working Group I) and Peter Clark of Oregon State University - used a new method that looks to the past to inform this future projection.

Continue reading "Sea level rise: not so fast" »

Posted by Anna Barnett on July 28, 2009
Categories: Climate prediction, In the News, Ocean science, Palaeoclimate | Permalink | Comments (2) | TrackBacks (0)

"Science has its limitation. You cannot substitute the knowledge that has been gained by the people living in cold deserts through everyday experience.”
Indian environment minister Jairam Ramesh says the developed world has needlessly raised the alarm over melting Himalayan glaciers.

Scientists find that not only is climate change shrinking sheep, it is making them lighter in colour.
Headlines such as 'Bye bye black sheep' draw attention to the increasing frequency of light-coated sheep in the Outer Hebrides.

"It would be a tiny step financially to keep this factory open, but it would be a huge statement about the government's commitment to the green economy."
Worker at wind turbine factory due to close this month accuses the UK of having incongruent policies.

"This is a dangerous thing, and I think people in Congress must understand this. Please don't use this weapon."
IPCC chair Rajendra Pachauri warns that trade tariffs in the US Waxman-Markey climate bill could dissuade developing countries from signing up to a new global deal.

Posted by Olive Heffernan on July 24, 2009
Categories: In the News | Permalink | Comments (1) | TrackBacks (0)

Blankets of low clouds shield and cool the Earth’s surface - but in a warming climate, will this safety blanket thicken, or will it deteriorate? That question has bugged climatologists for decades. A paper published in Science today (subscription) now offers convincing evidence that warming leads to fewer clouds, and thus exposure to more warming.

The positive feedback effect was observed in the northeast Pacific Ocean, where the relationship between short-term local meteorological conditions and cloud cover is fairly well understood. In contrast, scientists hadn’t previously said much about how this relationship plays out on a decadal scale - in part because any long-term data set would be viewed askance. Satellite cloud records go back only 25 years, and their accuracy can be wrecked by instrument drift and data gaps. Another type of cloud data, eyeball observations made from ships, is considered suspiciously subjective.

But in the new study, Amy Clement of the University of Miami and colleagues looked at both types of measurements from the northeast Pacific and found they were remarkably consistent. Clement says in a press release,

"The agreement we found between the surface-based observations and the satellite data was almost shocking. These are subtle changes that take place over decades. It is extremely encouraging that a satellite passing miles above the earth would document the same thing as sailors looking up at a cloudy sky from the deck of a ship."

The data showed that over the climatic ups and downs since the 1950s, periods of warming have dispersed the clouds. The authors then compared 18 global climate models to see if they could match the observations. Of these, just two showed the correct relationship between temperature, circulation and clouds - and only one of the pair, from the UK’s Hadley Centre, also responds to greenhouse gas forcing in a manner that matches the average response of the 18 models.

The Hadley model also happens to be one with highly sophisticated methods for simulating clouds, so it may point the way to incorporating the group’s discovery into future models.

Anna Barnett

Image: Jason Pratt, Creative Commons License

Posted by Anna Barnett on July 23, 2009
Categories: Anna Barnett, Atmospheric Science, Ocean science | Permalink | Comments (0) | TrackBacks (0)

As even the staunchest advocates will tell you, climate insurance is by no means a magic bullet. But clearly the tools of modern finance could certainly help make poor nations prepare for and respond to all manner of natural disasters big and small.

We explore some of these ideas in this week's issue of Nature, taking a quick look at how the insurance debate is playing out in the ongoing United Nations climate talks. The upshot is that some kind of insurance mechanism is likely to make it into whatever climate deal is struck in Copenhagen and beyond.

One commonly cited option is index insurance, which is tied to things like rainfall that can be measured objectively. This cuts down on costs by eliminating the need for audits and investigations. In the case of something like crop insurance, moreover, it could put money in the hands of farmers immediately after the rains fail - and before the hunger sets in.

Today these programs are being paid for largely by the farmers and nations buying the insurance, but industrialized nations would likely subsidize any insurance program deployed as part of an international climate agreement. The logic is that extreme weather variations - including droughts and heavy storms - are likely to increase in a warmer world, which means that both costs and premiums will rise as well.

A key challenge moving forward is how to scale up programs that benefit the world's poorest farmers and communities. Dan Osgood, a researcher at Columbia University's International Research Institute for Climate and Society, points out the pilot programs that are under way today have generally been deployed in areas where information - regarding weather, crops and the like - is available. This means it will only get more difficult moving forward.

In the case of the Ethiopian project discussed in our story, Osgood only had 15 years of satellite data on rainfall. The team has installed a rain gauge in the village of Adi Ha, which they hope to use in future years, but the team had no choice but to base their rainfall metrics on satellite data this year.

Osgood says the insurance question could also increase pressure on scientists and insurance companies to tease out the long-term impacts of global warming at very local scales. He was forced to grapple with the problem when he analyzed the satellite data and found a slight decline in precipitation around Adi Ha. Scientists can perhaps write that kind of trend off as an uncertainty and wait for more data. Insurance contracts, however, can't ignore such trends, because they are, by their very nature, priced according to uncertainty. The bigger the risk, the more uncertainty, the higher the price.

“It could be a climate trend, it could be just noise and uncertainty, or it could be a decadal process,” he says. "What’s cool about it is we don’t need to know in order to write the contract this year."

Posted by Jeff Tollefson on July 22, 2009
Categories: Jeff Tollefson | Permalink | Comments (1) | TrackBacks (0)

There’s an update over at Nature News on efforts to get a regulatory handle on carbon dioxide emissions from the shipping industry. I noted last month, when the International Maritime Organization was taking criticism for not moving faster on the issue, that an IMO official had said a July meeting might come up with ideas.

No such luck. The meeting wrapped up last week, and though progress was made on regulating pollutants that harm air quality, the issue of climate went unresolved. Although ships emit a variety of greenhouse gases, CO2 is the main culprit, outweighing other sources by almost ten-thousand-fold.

The accusation in June was that the IMO should have taken control of ships’ carbon footprints - a duty assigned to them by the Kyoto protocol - well before the Copenhagen conference. Coming to the IMO’s defense, an industry representative says they’ll find it easier to do it after December:

"The fact that the IMO cannot come to such agreement this year doesn't mean in any way that it's somehow hopeless," says Bryan Wood-Thomas, vice-president for environmental policy at the World Shipping Council, a trade group that represents about 90% of the cargo-container shipping industry. "Quite to the contrary, I think it will arrive at an agreement in the next year and a half," he says — once countries assess whether the results of the Copenhagen meeting change the context of the IMO's climate negotiations.

But if the IMO doesn't make this switch from crawl to sprint, the European Commission has said it will impose regulations on its own. The full article has more details.

Anna Barnett

Image: Flickr user "helmuts", Creative Commons license

Posted by Anna Barnett on July 20, 2009
Categories: Anna Barnett, Climate Policy, In the News | Permalink | Comments (0) | TrackBacks (0)

In the runup to Copenhagen, policymakers have been addressing China as the reigning developing-world heavyweight. But economist Nicholas Stern argued in a lecture last night that the moment is ripe for India to seize a leadership role.

"India, in my view, too often waits to hear the proposals of others and then puts its very fine minds to batting them back and explaining the myriad of reasons why they are inadequate," Stern said. "What I'm arguing for is... going out there and explaining to the rest of the world what needs to be done." In addition to his work on climate change, Stern also directs the India Observatory at the London School of Economics; he delivered the talk, at Chatham House in London, as the 30th Jawaharlal Nehru Memorial Lecture.

In contrast to the ever-diplomatic Stern, Indian prime minister Manmohan Singh has recently been blunt about the country's stance. Speaking after the G8 conference, when developing countries shied from signing on to a target of cutting global emissions 50% by 2050, Singh told the Economic Times of India, “There is a lot of pressure on India and China on the issue of climate change. We have to resist it.”

Continue reading "Stern urges India to lead on climate" »

Posted by Anna Barnett on July 16, 2009
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Shrug-worthy, disappointing, too slow, reactionary, lacking ambition, could-do-better: the scientist’s attitude to most UK politicians’ policy statements on reducing carbon emissions.

Today’s “low-carbon transition plan” looks different – although we could have done with it a lot earlier.

In a collection of four strategy documents which together proclaim themselves “the most systematic response to climate change of any major developed country”, the UK government plots out exactly how it plans to meet its legally binding targets for cutting carbon dioxide emissions.

Energy secretary Ed Miliband says that by 2020 he wants 40% of electricity to come from low-carbon sources: over 30% from renewables – overwhelmingly wind power, but also biomass, and tidal energy – and the rest from nuclear and carbon capture and storage. Heat and transport will also see vastly-boosted renewables contributions. By 2020, there will be 3,000 offshore wind turbines across the country and every home will have a smart meter. Every government department has been given its own carbon budget to follow. Thousands of ‘green jobs’ (undefined) will be created.

The ambition on paper is praiseworthy. It leaves only sizeable doubts about whether the government can match deeds to fine-sounding words – and whether they can persuade households and firms that they must pay increased costs on energy bills.

“Eventually the Government must move from analysis paralysis to doing and building," says Stuart Haszeldine, a geologist at the University of Edinburgh. “All the right plans are there, but it’s hard to believe that this is actually going to happen.”

Continue reading 'UK low carbon drive: at last the right sounds; now let's see it happen' at Nature's The Great Beyond blog

Posted by Anna Barnett on July 16, 2009
Categories: Climate Policy, In the News, Richard Van Noorden | Permalink | Comments (1) | TrackBacks (0)

Some glacial periods in the Earth’s more recent geological past have been cooler and more severe than others, despite very similar greenhouse gas concentrations and orbital parameters. What is it that decouples global temperature from carbon dioxide levels and the solar heat?

Changes in ocean circulation, particularly in the climatically crucial North Atlantic region, are the most likely candidate. A paper in Nature (subscription required) now suggests that some of these changes originate more than 10,000 kilometres away in the subtropical Indian Ocean.

Edouard Bard and Rosalind Rickaby analysed an 800,000-year record of sea surface temperature and ocean productivity from an ocean sediment core retrieved off the southeastern coast of South Africa (Editor's summary). This is the region where a portion of the warm and salty water carried southwards by the Agulhas current, the Indian Ocean equivalent to the Gulf Stream, leaks into the South Atlantic. The inflow compensates for the export of cold Atlantic deep water to other ocean basins. More importantly, it fuels the Atlantic overturning circulation which carries warm tropical surface water towards the poles, and cold deep water back towards the equator.

The strength of this heat conveyor depends on the position of ocean fronts, boundaries between water masses of different temperature and salinity, which are known to intermittently shift northwards and southwards.

Bard and Rickaby suggest that the Agulhas current between Madagascar and the African coast has almost come to a halt during times when the subtropical front in the Indian Ocean migrated northwards by up to 1,000 kilometres. Isotopic data from the sediment record suggest this has happened at least twice, namely during glacial stadials around 340,000 and 420,000 years ago. The closure of the Agulhas ‘valve’ might explain why these glacial periods have been severely colder than most others before and thereafter.

Continue reading "Indian Ocean: Gatekeeper to climate extremes?" »

Posted by Anna Barnett on July 15, 2009
Categories: Ocean science, Palaeoclimate, Quirin Schiermeier | Permalink | Comments (0) | TrackBacks (0)

The G8 meeting last week – the last get-together of the leaders of the world’s major industrialized nations before the United Nations climate summit in December - was loaded with expectations as to what Obama & Co might give climate negotiators to take with them to Copenhagen.

The answer, in a nutshell, is two degrees.

Is that enough? The Nature news story here has the context and offers two opposite expert views.

“The G8 announcement is depressing,” says economist Gwyn Prins, a co-author of the pointed anti-Kyoto polemic ‘How to get climate policy back on course’ (pdf file), whom I interviewed last week for the article.

“Politicians are mistaking making statements for actually doing something. We really need to try something different,” he says. He believes the prospect is “vanishingly small” for developed and developing nations to agree on a meaningful deal in Copenhagen.

Others are not so pessimistic. Hans Joachim Schellnhuber, director of the German PIK and something of an elder statesman of science-led global change diplomacy, is actually quite enthusiastic about the G8’s two degrees target, which he believes will breathe new life into international climate politics.

“Now we can calculate precisely how much greenhouse gas we can still afford to emit if we don’t want to exceed a given probability of getting into dangerous territory,” he says.

Continue reading "What the G8 target means" »

Posted by Quirin Schiermeier on July 15, 2009
Categories: Categories, Climate Policy, GHG emissions, Major Economies Meeting, Politics, Quirin Schiermeier, Topics, UN Conference on Climate Change, Copenhagen | Permalink | Comments (0) | TrackBacks (0)

A reconstruction of the Earth’s climatic history during a key hot period 55 million years ago has highlighted a yawning gap in our understanding: this period’s rise in carbon dioxide accounts for just half of its warming. Some as-yet-unidentified climate feedbacks could be at work, the scientists behind the research conclude.

The era under scrutiny is the Palaeocene-Eocene Thermal Maximum (PETM). Paleoclimatologists believe that the PETM could mimic our own future climate, because it’s thought to have kicked off with a pulse of carbon dioxide roughly equivalent to what humans are currently pumping out by burning fossil fuels. In a study published in Nature Geoscience (subscription), Richard Zeeb of the Universtiy of Hawaii and colleagues make a new, more precise estimate of the PETM’s carbon dioxide release based on ocean sediment records.

The increasing carbon levels caused ocean acidification that dissolved deep-sea carbonate compounds. By using measurements of this process along with a carbon-cycle model, the team inferred that during the period’s initial CO2 spike, no more than 3 billion tonnes of the gas was released over 5,000 years. Even before then, the planet looked like a greenhouse – it had a much warmer climate than today and about 1,000 parts per million CO2 in the atmosphere. Over the main phase of the PETM, the group estimates the CO2 level rose to 1,700 parts per million.

But according to the IPCC’s best guess at climate sensitivity, that 70% rise should have pushed up global temperatures 3.5 degrees Celsius at most. Other proxy records indicate, though, that temperatures soared by 5 to 9 degrees. In other words, the consensus climate sensitivity - the value, devilishly hard to pin down, for how much warming will result from a given greenhouse gas increase - doesn’t seem to be holding.

Continue reading "Unknown climate culprit for Palaeocene-Eocene warming" »

Posted by Anna Barnett on July 14, 2009
Categories: Anna Barnett, Climate prediction, Palaeoclimate | Permalink | Comments (0) | TrackBacks (0)

"My garage won't hold them. They've got to go someplace."
After scrapping plans for a gigantic 2,700-turbine wind farm because of technical problems, Texas entrepreneur T. Boone Pickens will put the 687 turbines he's already bought on four smaller sites.

"It's a perfect commentary on the potential problems of this approach. Plus, it's a sasquatch paper."
Jeff Lozier of the University of Illinois at Urbana-Champaign has projected climate-induced range shifts for Bigfoot to make the point that ecological models are only as good as the data that go into them.

"We'll be in until Christmas, so I'm not worried about it."
US Senator Barbara Boxer remains confident that climate legislation will pass through the Senate this year, despite the decision to delay it until Fall.

Posted by Olive Heffernan on July 12, 2009
Categories: In the News | Permalink | Comments (0) | TrackBacks (0)

Cross-posted from the Great Beyond

The world's biggest greenhouse gas polluters are poised to adjourn a series of meetings in Italy without any significant breakthroughs between developed and developing nations. Though hardly surprising, the news certainly reaffirms fears that it could be a long slog to Copenhagen.

In this week's issue of Nature, we take a look at some of the positions and ideas being put on the table by developing nations. The upshot is that many developing countries, recognizing the threats posed by climate change, are doing quite a bit to clean up their economies. Nonetheless, they remain understandably wary of binding requirements that might restrict their ability to lift themselves out of poverty.

Countries like India, China, Brazil and others are focusing on per-capita emissions within a historical context. From this perspective, industrialized nations have pumped far more than their fair share of pollution into the atmosphere, which provides a limited cushion for development powered by fossil fuels. The way China runs the numbers, industrialized nations would have had to stop emitting all together two years ago. Recognizing that it will be virtually impossible to achieve parity under such terms, Bolivia has proposed the concept of a "climate debt," illustrated in this graph, which is basically the difference between what industrialized nations should be allowed to emit on a cumulative, per-capita basis and what they actually emit.

In other words, industrialized nations can use up more than their fair share of the allowable emissions, but they must pay for it. This transfer of wealth is likely to be the crux of any deal that might be struck this year; developed countries know they are going to have to write checks, but they want assurances that those checks will be put to good use. One solution is to start out with sectoral approaches that guarantee certain types of policy and technology changes, which can reliably be counted on to reduce emissions.

As it happens, a PNAS paper out this week takes a different approach to climate equity by targeting wealthy individuals rather than wealthy nations. Although the end result is similar, their proposal does not cover historic emissions, which are at the heart of the proposals outlined above.

One thing is sure: No agreement can be struck unless the gulf between developed and developing nations is bridged. Barack Obama's ascension to the White House makes political progress possible in the United States, but politicians in the US and Europe know that slashing emissions in developed countries alone simply cannot solve the problem. Indeed, this is one of the principle arguments being raised against climate legislation that is poised to be taken up in the US Senate. And from this perspective, it's possible that progress on the international front is just as critical for striking a deal within the US as US participation is at the international level.

Posted by Jeff Tollefson on July 09, 2009
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Cross-posted from Jeff Tollefson on The Great Beyond

An international crew of academics this week boldly declared that the world is headed down the wrong track in trying to put a lid on global greenhouse gas emissions. But with global leaders pressing the issue in Italy this week, it's not clear that anybody is listening.

The team includes Gwyn Prins of the London School of Economics and Steve Rayner of Oxford University, who made a splash with their 2007 indictment of the Kyoto Protocol, dubbed The Wrong Trousers (Nature also published a summary of the article). Their latest paper, which includes additional authors, including Roger Pielke, Jr. at the University of Colorado in Boulder, maintains a hard line and advocates policies that directly promote energy efficiency and decarbonization in place of a messy global carbon market that might or might not do the work it is intended to do. The researchers see a model in Japan, long a leader on energy efficiency thanks in part to a dearth of domestic resources.

Although the BBC posted a story and the New York Times' Andrew Revkin included a blurb in his blog, the paper hasn't garnered much traction. To be sure, Japan has lessons to teach the world, and carbon markets are unlikely to solve all of the world's problems. But like it or not, given the amount of time and political capital that has been invested in the current negotiations, there's little appetite for radical new ideas.

This perspective was nicely summed up in the BBC's coverage by Tom Burke of Imperial College. He acknowledged that many of the authors' criticisms are valid but suggested that "nothing could be more harmful" than the solution they propose, which is to reverse course.

So far, however, that doesn't appear to be a danger. On Wednesday, G8 leaders backed the establishment of a global carbon market as part of a commitment to curb their emissions by some 80 percent by 2050. They also signed on to a goal, long held by the European Union, to limit global warming to 2 degrees Celsius. The question facing the Major Economies Forum, to be convened Thursday by US president Barack Obama, is whether major developing countries such as China and India will agree to the 2-degree goal and commit themselves to halving global emissions by 2050 in order to make it happen.

Posted by Olive Heffernan on July 09, 2009
Categories: Climate Policy, In the News, Jeff Tollefson, Politics | Permalink | Comments (0) | TrackBacks (0)

At the AGU Chapman Conference last month I met up with Lonnie Thompson, the alpine glaciologist who has spent more time above 20,000 feet than any other human. Despite being interrupted by last-minute demands from Peruvian customs officials - he was squeezing me in before taking off for a new expedition in the Andes - an unphased Thompson carefully laid out the past and present-day climate change that his work has uncovered. Here's an extract:

What information can you garner from glaciers?

Glaciers are like sentinels, and they're telling us that the system is changing. The first thing we look for in the ice is radioactivity from thermonuclear bomb tests in 1962–1963 and 1951–1952. Back in 2006, we drilled three cores in the southwestern Himalayas. At 6,050 metres, where those glaciers reach their highest elevation, we found that neither of these radioactive layers was preserved. The glaciers are being decapitated. Not only are they retreating up the mountain slopes, but they are thinning from the top down.

This same scenario is playing out on Mount Kilimanjaro in Africa. When we drilled there in 2000 we found the 1951 test preserved, but not the 1962 test. We've since continued to monitor those glaciers and we know that we've lost three metres of ice since 2000. If we had waited until this year to drill, we would not have found the 1951 bomb horizon, because that has now been lost.

What does that mean for climate science?

Once a glacier melts, the history it contained is gone forever, so there's an urgency in trying to collect the records before they are lost.

The loss of tropical glaciers is very telling because they're in such sensitive places. Half of the surface of the planet lies between 30° N and 30° S. That's where the heat that drives the climate system is received. It's also where 70 per cent of the 6.7 billion people on the planet live.

What's the effect on people as these glaciers disappear?

After this meeting, we're headed to Peru to drill new ice cores at two sites. That country contains 75 per cent of the world's glaciers. Eighty per cent of its population is in the desert on the west coast, and 76 per cent of the electricity comes from hydropower, from streams that are fed by glaciers in the Andes, all of which are retreating. Those changes are impacting the ability to produce hydropower, to irrigate crops in the desert and to provide municipal water supplies.

Read the full interview here.

Anna Barnett

Image: © Thomas Nash 2000. All rights reserved.

Posted by Anna Barnett on July 09, 2009
Categories: Anna Barnett, Cryosphere, Palaeoclimate | Permalink | Comments (0) | TrackBacks (0)

It's one of the biggest problems in the Earth's history: What prompted the Cambrian explosion of multi-cellular animal life? (Though calling it the 'Cambrian explosion' is a misnomer at this point; most geologists agree that life took off a bit earlier than the Cambrian 540 million years ago -- probably 50 million years or so before that boundary.)

Now, a new study in Nature [subscription] presents an intriguing explanation: It was photosynthetic life on land, beginning 850 million years ago, that allowed oxygen levels to rise in the atmsophere. Higher oxygen levels, in turn, allowed respiratory animals to get bigger. As I explain in an accompanying news story, the land life wasn't plants -- it was more likely a dense, mossy, worldwide matting.

The evidence is indirect: isotope records trapped in carbonate rocks formed in shallow seas. Some researchers are skeptical since fossil evidence is virtually non-existent. Moreover, the study will be controversial in geochemistry circles because the authors' interpretations of the isotope data is very different from another popular line of thinking, which sees radical changes in ocean chemistry closer to the Cambrian boundary as being the impetus for the animal explosion.
Image: Diego Cupolo

Eric Hand is a staff reporter in Nature's Washington Bureau.

Posted by Eric Hand on July 08, 2009
Categories: Palaeoclimate | Permalink | Comments (0) | TrackBacks (0)

Cross-posted from Geoff Brumfiel on The Great Beyond

I got to hear Al Gore speak today at the close of the World Forum on Enterprise and the Environment in Oxford, and I was amazed to be treated to a pop neuroscience lecture.

Rather than climate, Gore opened by talking about human psychology and physiology. Climate change, he said, is "ultimately a problem of consciousness". He went on: "What is being tested is the proposition of whether or not the combination of an opposable thumb and a neocortex is a viable construct on this planet".

That's pretty deep, but Gore got deeper. Evolution, he said, had trained us to to respond quickly and viscerally to threats. But when humans are confronted with "a threat to the existence of civilization that can only be perceived in the abstract", we don't do so well. Citing functional magnetic resonance imaging, he said that the connecting line between amygdalae, which he described as the urgency centre of the brain, with the neocortex is a one way street: emotional emergencies can spark reasoning, but not the other way around.

Gore went on to speak about lots of other stuff: how better management of soil would be critical to solving the climate crisis. How geothermal energy had the potential for enormous development, and how existing technologies, such as coal-fired power plants had to become more efficient.

But in the end, he brought it back to human consciousness. Until the majority of citizens perceive climate change as a true crisis, he said, politicians will be sluggish to act. That's the bad news. The good news, though, is that when we do decide to act, we will be able to do so more rapidly than anyone currently thinks is possible. "Just remember, when we become aware of what we have to do, and when we have the tools available to us to get the job done, it can change", he said. "We ought to approach this challenge with a sense of joy."

I'm not sure what it says about human consciousness, but it certainly is an interesting insight into Mr. Gore's psychology. I'm curious to hear what neuroscientists make of his analysis.

If you want to hear the whole speech, have a listen here (audio quality isn't brilliant, sorry about that).

Geoff Brumfiel is a senior reporter for Nature

Posted by Olive Heffernan on July 07, 2009
Categories: Geoff Brumfiel, Society | Permalink | Comments (1) | TrackBacks (0)

Our last day in Lindau was largely taken over by recording the remainder of our interviews for the climate change film. So much so, that I’m just getting to blog it now.

On Friday, all 600 students, the Nobel laureates, and several media-types were shipped to Mainau island, home of the late Count Lennart Bernadotte, who instigated the Lindau meeting of Nobel Laureates some 57 years ago. There, we were greeted by his daughter Countess Bettina Bernadotte, ahead of a panel discussion on climate change, chaired by Geoffrey Carr, science editor at the Economist.

The panel discussion covered a lot of ground, albeit superficially, on what we need to reduce emissions, what technologies we can employ, and who needs to take the lead. It included Rajendra Pachauri and Thomas Stocker from the IPCC, Danish political scientist Bjorn Lomborg, laureates Mario Molina and Richard Shrock, and Cornelia Quennet-Thielen, State Secretary at the German Federal Ministry of Education and Research.

The panel potentially would have covered more detailed ground if Lomborg hadn’t been busy having it out with the other panellists on how much attention, and money, we should be dedicating to climate change.

Historically, there has been disagreement between climate scientists and Lomborg, partly owing to the fact that Lomborg simply doesn’t view climate change as a high priority on the list of global problems. More specifically, he has riled climatologists in the past with his disdain for what he sees as scientific alarmism, rather than consensus.

Continue reading "Lindau09: It’s a wrap" »

Posted by Olive Heffernan on July 07, 2009
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For the better part of two decades, international climate policy has held industrialized countries responsible for the world’s carbon habit. But today developing-country emissions make up more than half the world’s total and are climbing faster than emissions in the wealthy North. A paper just out in PNAS offers a new argument that aims to bring these troubling emissions into the fold of a global climate deal - while preserving a sense of equity and the right of the planet's poorest to seek prosperity.

The work comes from Princeton’s Shoibal Chakravarty and a team of colleagues including Stephen Pacala and Robert Socolow, who previously brought us the handy concept of stabilization wedges. The principle: instead of asking the wealthiest nations to shoulder the burden of greenhouse gas cuts, ask the wealthiest individuals in both developed and developing countries to do so.

They aren’t suggesting that the UN hand out carbon ration cards or ground private jets. Instead, nations would be given emissions targets based on how many high-earning, high-emitting citizens they have. That means that although developed countries would still have to cut their emissions most quickly, developing countries with a growing middle class, such as China, would also be required to veer away from business as usual.

While Reuters headlined their story “New climate strategy: track the world's wealthiest”, Scientific American hits the real bottom line with “Who's to Blame? Making Poor Nations Share the Cost of Fighting Climate Change”. Socolow says, “I think the world understands that ... the size of the job required and the speed at which we have to proceed is incompatible with a further granting of a free pass to the developing world.”

But for those countries to relinquish their free pass, they would have to see the burden sharing as fair. That’s where the paper’s economic formula comes in.

Take a country at any point in the future, say the authors, and you can estimate how its projected greenhouse gas emissions are distributed among its citizens by assuming that people with higher incomes emit more. You then put all these high and low emitters of the world into a single distribution and chop off the top of the curve (see right) - taking out a bigger or smaller section depending on how much gas you want to exclude from the atmosphere. This yields a recommended ceiling on individual emissions - in this example, about 10.8 tons CO2 per person per year - that applies equally to all countries. To then come up with a national target, follow the cartoon below.

The authors also try a scenario with an added twist: an emissions floor as well as a ceiling. The idea here is to alleviate extreme poverty by letting people who are now using less than, say, a ton of CO2 per year come up to that low level. The group at first had doubts about this complication, says Socolow, “but we found that if we allow fossil fuels where they’re useful, the extra work that the rest of us have to do is very small.”

Continue reading "Climate equity with an economic twist" »

Posted by Anna Barnett on July 07, 2009
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Sir David Attenborough joined scientists at the Royal Society in London today to warn that saving coral reefs from mass bleaching in a warmer ocean would take more than just limiting carbon dioxide emissions. We’ll have to start actively removing the gas from the atmosphere - perhaps through geoengineering, said the scientists. As the reefs go, so goes the ocean, warned Attenborough, who said that reefs act as "a barometer of the malaise that is afflicting the ocean at large.”

The one-day meeting, put on by the Royal Society, the London Zoo and the International Programme on the State of the Ocean (IPSO), brought together about two dozen coral reef and climate experts to draft a statement on the reefs’ sensitivity. The group's statement concludes that stabilizing atmospheric carbon dioxide concentrations at 450 parts per million would still allow for climate change and ocean acidification leading to catastrophic losses. “To ensure the long-term viability of coral reefs,” they say, the level has to be brought down from today’s 387 parts per million to “significantly below 350 ppm”. Geoengineering is one option that could be considered for soaking up existing carbon, said Alex David Rogers of IPSO at a press briefing on the new document.

Continue reading "Rewind emissions to save reefs" »

Posted by Anna Barnett on July 06, 2009
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Why carbon dioxide concentrations over the past 24 million years or so have never dropped below 200 parts per million, despite environmental conditions that have been favourable for CO2 drawdown by rock weathering and sedimentation, has always been a bit of a mystery.

Now scientists suggest an almost provocatively simple mechanism that might have kept the planet from cooling more severely than it actually did during past glacial climates: Changes in terrestrial vegetation stopped the weathering-driven decline in atmospheric CO2 concentrations which else would have turned Earth into a lifeless freezer.

Weathering is known to be largely controlled by vegetation. So the team, led by Mark Pagani of Yale University, describes in a paper in Nature today a negative feedback whereby limited plant growth during cold conditions slows down the rate of weathering and sedimentation, thus preventing carbon dioxide levels from dropping even further. An editor's summary of the paper is here.

This “bold and provocative” hypothesis provides an “elegant twist” on existing ideas about climate-vegetation interactions, Yves Goddéris and Yannick Donnadieu write in an accompanying News and Views article (subscription required).

But the proposed feedback mechanism raises contentious issues as well. For example, Goddéris and Donnadieu argue that in the tropics the role of vegetation cover in the climate system might not be as significant as proposed.

Quirin Schiermeier

Posted by Quirin Schiermeier on July 02, 2009
Categories: Categories, Biosphere feedbacks, Climate Science, GHG emissions, Palaeoclimate, Quirin Schiermeier, Topics | Permalink | Comments (0) | TrackBacks (0)

Jane Qiu has an interesting interview on Nature News with aquatic ecologist Breck Bowden of the University of Vermont, who is heading up new research looking at what happens when thawing ground in the Arctic begins to fall apart. Here's an excerpt:

Last week marked the start of a US$5 million project to study the effects of thawing permafrost on ecosystems in the Arctic. Based at the Toolik Field Station in northern Alaska and sponsored by the US National Science Foundation, the project will look at the impact of thermokarsts — the scars and pits left behind as melt water from permanently frozen ground leaks away, and soil and rock collapses in its wake.

The project was inspired by a serendipitous discovery in 2003, says Bowden:

My colleagues and I were flying over the high Arctic in search of research sites. We noted that the Toolik River was brown and muddy, which was odd as it hadn't rained recently. As we went further upstream, we came to a tiny stream that was washing tons of thermokarst sediments into the river. We were astounded how this tiny feature was influencing the river 40 kilometres downstream. The volume that had been displaced was enough to smother the bottom of the entire river. The sediments would release a lot of nutrients normally locked up in permafrost into freshwater cycles. That's got to have a significant impact on the ecosystem.

Read the full interview here.

Anna Barnett

Posted by Anna Barnett on July 01, 2009
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It’s Wednesday in Lindau and I’ve spent a chunk of the past 24 hours recording sections of the film about climate change that we’re making here.

Yesterday afternoon, I had the pleasure of talking with Mario Molina and Sherry Rowland about their work on ozone and their views on science informing policy. We were joined by three young, enthusiastic scientists who are working on various aspects of climate research – solar technology, biofuels and ocean health – and are here at Lindau to interact with the laureates.

Molina and Rowland have a lot to say on the issues of ozone and policy, of course. When they called for a worldwide ban on CFCs, following their discovery that CFCs were destroying the ozone layer, they were, in many respects, pioneers. But though their efforts ultimately led to the phasing out of CFCs, their results – and outspoken views – were initially greeted with caution from the scientific community. I asked them what the young scientists working on climate change can learn from their experience.

Rowland was adamant that young scientists should not be afraid to speak up on the implications of their research. I queried them on how far researchers should go in speaking up. Would they, for example, now call for a worldwide ban on the use of coal, given that coal is such a significant contributor to the problem of climate change? They both responded that a worldwide ban would be appropriate, if carbon capture and storage (CCS) was available. Molina added that we should be cautious of building new power plants that will tie us into using coal for the next 30-50 years, unless we have developed CCS technology.

I met the young researchers – Brandy and Brian from the US, and Faroha from Pakistan – again this morning at 730am to catch up on their experiences at Lindau so far. They all got a lot out the session with Rowland and Molina, who were both thoroughly engaging. Of course, I can tell you all of this on the blog, but it will be much more convincing to see the film once it is on nature.com. Out of an hour of filming, I’m guessing that five minutes, at most, of yesterday’s session will make it into the final cut.

After hearing talks on sustainability and energy from Harry Kroto and Walter Kohn, this afternoon, I recorded some of the narrative links for the film. The face-to-camera pieces are by far the trickiest!

The next piece will be recorded Friday as we make our way by boat to Mainau island – home of Countess Bettina Bernadotte – where a panel on climate change is being convened. I’ll be back with an update from that on Friday.

Olive Heffernan

Posted by Olive Heffernan on July 01, 2009
Categories: Lindau Nobel Laureate Meeting, 2009, Olive Heffernan, Politics, Society | Permalink | Comments (2) | TrackBacks (0)