The paper's authors, Keenlyside et al., have yet to accept or reject the bet, and it's not available to any other cooling proponent who may be feeling lucky. But if your opinion on global warming is burning a hole in your pocket, you have some options. Brian Schmidt's Backseat Driving, for example, lists several standing offers to all takers.

Those like Schmidt who back the scientific consensus that the Earth is warming, however, have had a hard time convincing anyone to gamble large sums on cooling. A few bookmaker's highlights:

This could have a dramatic affect on the Amazon rainforest. A team led by Peter Cox of the University of Exeter, UK, reports in a paper in this week’s Nature that reductions in aerosol pollution will tremendously increase the risk of severe drought in the Amazon region. Here is an editor’s summary of the paper.

Although it accounts for nearly a quarter of the world's fresh water, drought is not unknown in Amazonia.

In the dry season, from July to October, rainfall in the region is linked to sea surface temperatures (SST) in the tropical Atlantic. In years with a pronounced temperature gradient - warming of the tropical Atlantic north of the equator relative to the south – the normal’ position of high and low atmospheric pressure systems can shift, delaying or suppressing the onset of the South American monsoon.

The effect has been observed in 2005, when large parts of the Amazon region were hit by the worst drought in decades. See a Nature news story by Mike Hopkin here (subscription required) and a New York Times story here about the devastating event.

Cox thinks that the 2005 drought was a harbinger of things to come. Their “simulations for the 21st century show a strong tendency for the SST conditions associated with the 2005 drought to become much more common, owing to continuing reductions in reflective aerosol pollution in the Northern Hemisphere.”

Droughts like in 2005 will happen every two years by 2025, and in nine out of ten years by 2060, the model suggests.

How robust is this dire prediction? The Amazonian climate, for reasons not quite understood, is notoriously difficult to simulate. But the Hadley Centre’s climate model which was used for this study has previously reproduced features of the regional climate with greater accuracy than other models.

In Mike Hopkin's words, “the ultimate fear is that the Amazon forest - often touted as an invaluable piece of armour against climate change - could become part of the problem rather than a key element of the solution. Droughts make it more likely that it will become a net source of greenhouse gases to the atmosphere, rather than mopping them up.”

Quirin Schiermeier

You can vote or comment on the importance of the new paper in the Journal Club of Nature Reports Climate Change.

Keenlyside and colleagues’ model uses a very simple ocean initialization method in which they add heat to or remove it from the ocean surface until sea surface temperatures across the globe are close to observed values. They use their model to produce a set of retrospective ‘forecasts’ starting from earlier states, which they test against what actually happened. Their system produces refined temperature predictions a decade ahead for large parts of Europe and North America.

Whether their prediction of a plateau for warming for a decade in North America and Europe is correct or not, their research may signal a shift that many climate researchers have been calling for for awhile now — toward service-oriented climate science ...

I am sure that this is an excellent paper by world class scientists. But when I look at the broader significance of the paper what I see is that there is in fact nothing that can be observed in the climate system that would be inconsistent with climate model predictions. If global cooling over the next few decades is consistent with model predictions, then so too is pretty much anything and everything under the sun.

Cross posted by Daniel Cressey on The Great Beyond

With an uninterrupted 17-million year sediment record of Antarctic’s climatic past now available, scientists are hoping for unique new insights into the continent’s climatic past.

A few initial results of the Antarctic Geological Drilling programme (ANDRILL) were announced last week at the general assembly of the European Geosciences Union in Vienna. There is an online news story here.

Antarctica’s ice sheets, so it seems, respond more sensitively to climate fluctuations than has been assumed. During warmer periods, the West Antarctic Ice Sheet and its floating extension, the western Ross Ice Shelf, have shrunk substantially. Some 3.5 million years ago the ice seems to have disappeared completely for around 200,000 years. There were snow-capped mountains, alpine trees, gushing rivers, quiet lakes – the frozen continent was a place where you would love to go fishing or hiking, were it not for the midges.

The world was warmer then than it is today, but not substantially so. If temperatures continue to rise, glaciers in Antarctic’s warmer western part might begin to retreat again before long. A few million years ago, Antarctic melting probably raised sea levels globally by 10 metres or so. If history repeats itself, we’re headed for trouble.

Quirin Schiermeier

Whereas 20 years ago the discovery that the stratospheric ozone layer was thinning led to international prohibitions on ozone-eating chemicals, this new study reflects concerns about excess ozone produced nearer to the ground, in the troposphere, by reacting pollutants. Tropospheric ozone is a greenhouse gas - and although carbon dioxide still gets the most column inches, other greenhouse gases such as ozone (see also methane) are drawing more and more scientific attention.

Previously, the best estimates of the radiative forcing from ozone - its planet-warming power - came from simulations. The latest IPCC report used several such models to assess forcing from anthropogenic ozone alone, excluding ozone from natural sources, and came up with a range of values from 0.25 to 0.65 watts per square metre (in comparison, forcing by all anthropogenic greenhouse gases together was estimated at 1.6 watts per square metre). Now, NASA's Aura satellite has collected enough measurements of infrared radiation and ozone thickness in cloudless patches of sky to pin down the combined effects of natural and human-produced ozone. According to these data, the global average forcing in the year 2006 was 0.48 (+/- 0.14) watts per square metre. No surprises, but a palpable step forward in the hardworking and sometimes underappreciated field of Earth observation.

Anna Barnett

Image: Artist's rendering of Aura satellite, NASA

The current issue of Nature has a feature about the state of the Greenland ice sheet (See also the related editorial dealing with the state of polar research funding).

I got started on this story at the American Geophysical Union meeting last December, in which session after session presented new data about the extent of summer melt in Greenland. Information from the GRACE satellites shows that the overall mass balance of the ice sheet is dropping steadily, and although surface melt varies quite a bit from summer to summer, two of the last three years have seen record levels of melt.

“2007 was a shocking year,” Scott Luthcke, who works with GRACE at NASA’s Goddard Space Flight Center in Maryland, told me later.

One record melt season does not spell the end of Greenland, of course, and journalists must always be wary about sounding too alarmist based on short-term records. But overall, the outlook for Greenland is simply not good: Changes in speeds of the island’s outlet glaciers show that, no matter whether they are advancing or retreating, they are far faster at changing their behavior than anyone had thought before.

As the article was going to press, we learned that another pair of key Greenland papers would appear the next day online in Science. Such is the peril of scheduling features far in advance while knowing your competitor journal has interesting papers under review.

The basic point of the two new papers -- that vast quantities of meltwater can form and then drain away atop the ice sheet each summer – made it into my feature anyway. But if you want more details, check out the original papers at the Science Express website. One paper, with lead author Sarah Das of the Woods Hole Oceanographic Institution, reports on a 4-kilometre-long melt lake that vanished into the ice sheet within the space of two hours. The other, with lead author Ian Joughin of the University of Washington’s Applied Physics Laboratory, describes seasonal speed-up in ice flow along Greenland’s western flank – though not so much in the outlet glaciers. Together, the papers confirm how meltwater likely helps lubricate the slippage of the ice sheet towards the ocean.

If you’re still looking for more things Greenland, check out the recent posting on RealClimate that again suggests the details of how Greenland melts are more complicated than we thought.

And if you just need a fix of gorgeous Greenland pictures, click on over to the Extreme Ice Survey project of photographer James Balog and others. We used only one of Balog’s iceberg images in my Nature feature, but his time-lapse work of melting glaciers is stunning.

Alexandra Witze

Image credit: NASA/GSFC VISUALISATION STUDIO; SOURCE: S. LUTHCKE

The ability to measure greenhouse gases from space, soon to become a reality, could answer this question.

Currently, it’s virtually impossible to identify the exact source – and destination - of greenhouse gases, a prominent theme at this year’s European Geosciences Union conference in Vienna.

But, according to scientists speaking today at the conference, this is all set to change within the coming year when two major satellites designed to monitor greenhouse gases will be launched into space.

Due to leave Earth on December 15, the first of these is the Orbiting Carbon Observatory (OCO), a US$300 million-or-so innovation of scientists and engineers at NASA’s Jet Propulsion Laboratory in California. The Japanese version, known as the Greenhouse Gases Observing Satellite, or GOSAT, has an anticipated launch date in January or February 2009.

For a detailed low-down on the satellites and how they will work, see Amanda Haag’s news feature in Nature (subscription) last December. Since then, the scientists have mostly been testing and calibrating the instruments to make sure they work once they’re orbiting the Earth.

Within a year or two, if not sooner, they will enable scientists to identify major sources and sinks or carbon, says Charles Miller, one of the Principal Co-ordinators of the OCO mission. The greenhouse gas measurements taken by the instrument, which will orbit the planet 14.5 times per day, will be three times more precise than any trace gas measurements ever taken from space.

All-in-all, the missions represent an unprecedented effort to collect global climate data from space. While this is fascinating from a scientific perspective, it should also have some interesting political implications by enabling the easy identification of climate culprits.

“If one were to imagine a way to monitor or verify [emissions], then this would be the way to go”, says Miller. For instance, it should quash (or raise, depending on who you’re talking to) fears that nations claiming credits for avoiding deforestation under the Kyoto Protocol will be able to divert the problem elsewhere.

Miller says they often joke that the instrument could detect the greenhouse gas emissions of serious carbon heaveyweights from space. But while the new satellites won’t realistically help reporting on individual carbon crimes, it could act as a ‘big brother’ to keep countries in line with their Kyoto commitments. Personally, I’m curious to know the OCO’s own carbon footprint!

That’s all from me from this year’s European Geosciences Union conference in Vienna. Over and out….

Olive Heffernan

Following evidence published last year showing that both the Southern Ocean and North Atlantic Ocean have weakened as carbon sinks in the past two decades, the new results suggest that the trend has recently reversed in the North Atlantic.

Scientists have feared that the weakening trend could be a long-term impact of global warming and that it could be typical of the ocean as a whole, which absorbs an estimated 25 per cent of anthropogenic carbon dioxide emissions yearly. If the ocean switches from a storehouse to a source of the greenhouse gas, this would jeopardise efforts to stabilise atmospheric greenhouse gas levels.

Speaking at a press conference at the EGU assembly yesterday, Ute Schuster from the University of East Anglia in Norwich, UK and Christoph Heinze at the University of Bergen, Norway, presented the results of a yearly analysis of carbon dioxide fluxes across the North Atlantic Ocean.

Previously, Schuster and colleagues showed that carbon uptake by the North Atlantic had halved between the mid-1990s and the early 21st century. But further analysis of the data on a year-by-year basis has shown that the uptake of carbon dioxide in the region has been increasing since 2002 and showed an even greater increase, relative to the early 2000s, in 2005.

The researchers caution that the results are preliminary and are not yet published. The coverage was poor in 2006 and they have not yet finished the analyses for 2007, but they say that the results so far indicate that the trend in weakening of the North Atlantic carbon sink is not linear.

The reasons for this variation are unclear. “I personally think we can’t say with confidence that the trend [in weakening sinks] is attributable to [anthropogenic] climate change”, says Schuster. Surface circulation in the North Atlantic has changed in recent years, she says, but these changes could be due to natural climate variability. Specifically, the North Atlantic Oscillation, a large-scale atmospheric pattern that has important impacts on European climate, could be influencing the rate of carbon dioxide uptake.

It's called the Climate Collaboratorium. Here's what it might look like, in part:
(click for larger version, or download the original PDF)

What you see is the heart of the idea, a discussion structure known as an 'argument tree'. Mason Inman*, writing about the project for Nature Network recently, summarized it well:

The structure requires people to present their comments in one of four categories: issues to be addressed, options for resolving those issues, the pros in favor of various options, and the cons against them. In this way, the debate could become self-organized, making it easier for people to see what’s been said, and whether points have been supported or rebutted.

Succinct, logical debate threads instead of arguments spread over dozens of sites... ideas neatly aggregated rather than forgotten with the next news cycle... pardon my nerd-drool.

But will it work? Last December, Klein and two researchers at the University of Naples tried out a prototype on 220 Italian engineering students, asking them to create an argument tree on the question "What is the future of biofuels?" The students seemed to love the forum - their steady 24/7 stream of posts totaled over 5,000 after two weeks - but they weren't particularly good at keeping the discussion on track. The argument trees needed continuous pruning and rearranging by a dedicated group of moderators, who would have to make up 5-10% of the user population in a larger-scale Collaboratorium, the researchers estimated.

Klein is now starting more tests with Swiss and Italian students that will evaluate whether the Collaboratorium produces superior content and better-informed participants compared with ordinary wikis and forums. How to arrange for quality control in the project's next phase, however, is still something of an open question. Climate modeller and RealClimate blogger Gavin Schmidt (who's recently defended climate blogging in Nature Geoscience (subscription) and on RealClimate) told Inman* that generating respect for an open forum on climate "is by far the most challenging aspect of this proposal". Doubtless, many top climate scientists - who may at times volunteer half their workload toward the IPCC reports already - wouldn't get around to participating in the fledgling project. Fortunately, they do have grad students.

The fully realized Collaboratorium, as outlined in this paper by Klein and collaborator Thomas Malone, would be even more ambitious. Their vision relies heavily, for example, on users building their own climate models that are integrally linked to the speculation and debate going on in the argument tree. Above all, though, Malone and Klein stress the need for a more powerful tool to help us get our collective heads around climate change:

Today's on-line discussion forums, blogs, and chat rooms do a good job of encouraging lots of people to express their opinions and share them widely. But these systems are not very good at supporting evidence-based, logical deliberation: the quality of contributions can vary enormously.

Andrew Leonard at Salon has aptly compared this to "saying nuclear bombs do a good job when employed for purposes of mass destruction, but are not so great for handcrafting quality woodwork."

What do you think, climate debaters? Could a more sophisticated approach force out a high-quality product?

Anna Barnett

[UPDATE: Klein also pointed me to this 10-minute video summarizing the Collaboratorium structure and its differences from traditional forums]

Either the word on the street that geoscientists have a great fondness for beer is not simply an urban legend, or the research community is very interested in how we're extending our reach further into the earth sciences. I suspect it's a combination of both.

Most of those I spoke with asked one or more of the following:

Should I submit my paper to Nature or Nature Geoscience?

What are the chances of getting my manuscript published in Nature Geoscience?

If my paper is rejected from Nature, can I resubmit to Nature Geoscience?

When will Nature Geoscience have an impact factor?

Why did you cover such and such a story in Nature or on Nature Reports Climate Change? (geoengineering was a big one here; I guess readers were curious about why we might cover something that's still quite conceptual, such as the Lovelock and Rapley proposal). Personally, I think such topics are worthy of discussion within the scientific community especially at the conceptual stage. I for one, am interested in whether our readers think that research efforts and funding should be directed towards such big potential solutions with high risk of failure).

Others were curious as to why Nature, recognised for its rigorous editorial control, has so firmly embraced blogging, which again raises the split opinions on whether web 2.0 is a worthwhile means of communicating science, as discussed recently here and on RealClimate.

The discussions took place in the first ever geoengineering session at an EGU annual assembly, held in recognition of the fact that it just may be time to start considering the need for a climate emergency response system, should our mitigation efforts fail to work...or indeed, fail to kick off.

Although the concept of manually interfering with the Earth’s climate on a large scale has been the subject of much controversy, not least in the pages of Nature, less attention has been given to such bespoke geoengineering to tackle specific potential impacts.

One such idea, put forward by Oliver Wingenter at the New Mexico Institute of Mining and Technology, involved enhancing the ocean with sulphur to prevent or reverse sea level rise.

In a proof-of-concept trial in the Southern Ocean, Wingenter and colleagues showed that fertilizing just 2% of the Southern Ocean could prevent net ice loss and reduce thermal expansion in the region enough to slow sea level rise.

Such drastic interventions might by just what’s needed, given research presented here in seperate press conference this morning by Svetlana Jevrejeva of the Proudman Oceanographic Laboratory, which further adds weight to the body of evidence that sea level rise is happening more rapidly than predicted in the IPCC’s latest report. The estimate released today says that it could be as as much as 1.5 metres (4.9 feet) by the end of this century.

I'm in sunny Vienna this week for the European Geosciences Union general assembly, a yearly gathering where several thousand scientists abandon their field and lab studies for an entire week to get together and talk earth, planets and space.

With over 8,000 participants, this year's meeting, held at the Austria Vienna Centre on the banks of the Danube, will be the society's largest yet.

Climate change and energy occupy sizeable slots on this year's programme; hence my schlep across to Austria to meet with some of the authors behind the 12,000 abstracts.

Following from a spate of recent coverage in Nature and on NRCC, the threat of a warming world on global water resources emerged here today as one of the issues du jour. This time, the question was whether the world's water supplies from mountains and highlands, known as the world's natural "water towers", will still be able to quench our thirst in fifty years.

Speaking at a press conference here this afternoon, hydrologist Daniel Viviroli of the University of Bern in Switzerland explained that these "water towers" supply on average three to five times more runoff to rivers than do lowland areas and are a primary water source for most of the world's major rivers.

This is especially important in dry regions where water is in short supply and in mountainous regions with glaciers that supply runoff from snowmelt in spring.

On a global level, 7% of mountain regions have a key role in supplying water to lowlands and their dependant populations. From the Rocky Mountains supplying the Colorado River Basin to the Lesotho highlands supplying South Africa, the water runoff from such "hotspots" is likely to diminish in the future, the scientists warned.

A further 37% play a crucial supporting role, said Viviroli, and may also be under threat, though he added that the timescale and nature of such changes are, as of yet, highly uncertain.

One of the issues, highlighted by Bruce Molnia of the US Geological Survey, is that in some regions such as North America and Afghanistan, the period of runoff is now shorter because snow arrives later and melts earlier.

Given that 70% of the world's population is based in lowland regions with natural "water towers" providing both drinking water and faciliatating food production, many millions could be affected.

Carmen de Jong, a research scientist who works on the Europena Alps, said that in some areas where glaciers are small, the water supply from high elevations could be gone in 30 years time unless there is enough precipitation in summer time to compensate for the loss.

Philip Mote, research scientist at the University of Washington, warned that we need to be careful about specifically attributing all such changes to anthropogenic warming, adding that the most serious human impacts in fifty years time will likely be south of 50 degrees latitude.

I'll be blogging throughout the week until the conference ends on Friday, so tune in here daily for the highlights on climate change and energy from EGU 2008. My colleague Quirin Schiermeier will also be blogging over on the Nature's In the Field blog with coverage from the climate and energy streams and more.

Olive Heffernan

Photo: Snowmelt runoff fills a reservoir in the Rocky Mountains near Dillon, Colorado. Credit: Scott Bauer, US Agricultural Research Service.

James Hansen and Michael McCracken - two extremely prominent and vocal climate scientists - have rallied behind a US high-school senior who questioned statements in his civics textbook that play up scientific uncertainty on global warming. Now the book's publisher, Houghton Mifflin, is promising to reassess its accuracy (AP, Dot Earth, Grist, Treehugger). From the AP:

Legal scholars and top scientists say the teen's criticism is well-founded. They say "American Government" by conservatives James Wilson and John Dilulio presents a skewed view of topics from global warming to separation of church and state. The publisher now says it will review the book, as will the College Board, which oversees college-level Advanced Placement courses used in high schools.

The student, Matthew LaClair, was already an experienced secondary-ed whistleblower, having taped and exposed religious comments his history teacher made in class last year. He contacted the Center for Inquiry, a pro-science think tank, to point out passages like:

"Science doesn't know whether we are experiencing a dangerous level of global warming or how bad the greenhouse effect is, if it exists at all."

"The earth has become warmer, but is this mostly the result of natural climate changes, or is it heavily influenced by humans putting greenhouse gases into the air?"

Some wording that LaClair highlighted from the 2005 textbook used in his class was toned down in a more recent edition. For example, "Science doesn't know whether we are experiencing a dangerous level of global warming or how bad the greenhouse effect is, if it exists at all," was changed to simply "Science doesn't know how bad the greenhouse effect is." Andrew Revkin at Dot Earth parses this:

As we’ve written many times, the climate system’s response to rapidly rising greenhouse gas concentrations remains laden with uncertainty. A doubling of concentrations from the long-term ceiling of 280 parts per million for carbon dioxide before the industrial revolution would most likely raise global temperatures 3.6 to 8.1 degrees Fahrenheit, by the latest I.P.C.C. analysis. So in that legalistic sense, it’s true that science hasn’t defined “how bad” climate change will be.

And that's about the best you can say of these passages, as Revkin, Hansen, McCracken and the Center for Inquiry all make clear in their point-by-point critiques. A response from Houghton Mifflin posted by Revkin falls well short of addressing the problem: the book's authors are describing a climate debate that sounds almost nothing like the IPCC's painstakingly agreed reports. Instead, as Hansen wrote, "these statements are aimed at giving students the mistaken impression that the scientific evidence of global warming is doubtful and uncertain" - a strategy that's familiar to Hansen.

Anna Barnett

Photo: dcJohn

The BBC is facing allegations that it altered a news story about climate at the behest of an activist. A series of emails from BBC reporter Roger Harrabin and activist Jo Abbess were posted on the Campaign Against Climate Change website on April 4th. After a series of back and forths Harrabin writes “Have a look in 10 minutes and tell me you are happier. ... We have changed headline and more”. The original headline - Global Warming ‘dips this year’ – changed to the current Global Temperatures ‘to decrease’. Needless to say as soon as these emails were noticed they were picked up by unhappy sceptic bloggers (here, here and here for example). The BBC told us:

A minor change was made to the "Global temperatures 'to decrease'" piece on our website to better reflect the science. A few people including the report's authors, the world meteorlogical organisation, pointed out to us that the earlier version had been ambiguous.

Cross-posted from Daniel Cressey on The Great Beyond

It’s been one of the most challenging articles I’ve had to write, as I had to leave out so much, but at the same time one of the most satisfying. This is a hugely important topic. Buildings account for up to half of all energy consumption, and are the biggest single contributor to greenhouse gas emissions. Much attention is given to exotic future remedies, such as carbon sequestration and clean coal. But a way to slash emissions using existing technologies is sitting under our noses: simply rethinking how we design the buildings we live and work in, to use much less energy.

The arguments for building with energy needs met largely by marrying with the local environment and passive strategies are so compelling that the research for this article is persuading me to switch my own plans to buy a place in French Touraine, where I live, to instead build a zero-energy home — no small challenge, though, given that French builders are far behind their German, Swiss, and Austrian neighbours here.

Image: Low-income “passive” terrace houses in Lindas, Sweden; M. Wall