E.J. Rohling et al., Nature Geoscience, June 2009, Antarctic temperature and global sea level closely coupled over the past five glacial cycles

Nature Geoscience, 2 (2009) 500-504, published online 21 June 2009; doi:10.1038/ngeo557

Antarctic temperature and global sea level closely coupled over the past five glacial cycles

E. J. Rohling^*,1, K. Grant¹, M. Bolshaw¹, A. P. Roberts¹, M. Siddall^2,4, Ch. Hemleben³ and M. Kucera³

Abstract

Ice cores from Antarctica record temperature and atmospheric carbon dioxide variations over the past six glacial cycles^{1, 2}. Yet concomitant records of sea-level fluctuations—needed to reveal rates and magnitudes of ice-volume change that provide context to projections for the future^{3, 4, 5, 6, 7, 8, 9}—remain elusive. Reconstructions indicate fast rates of sea-level rise up to 5 cm yr^-1 during glacial terminations¹⁰, and 1–2 cm yr^-1 during interglacials^{11, 12} and within the past glacial cycle¹³. However, little is known about the total long-term sea-level rise in equilibration to warming. Here we present a sea-level record for the past 520,000 years based on stable oxygen isotope analyses of planktonic foraminifera and bulk sediments from the Red Sea. Our record reveals a strong correlation on multi-millennial timescales between global sea level and Antarctic temperature¹, which is related to global temperature^{6, 7}. On the basis of this correlation, we estimate sea level for the Middle Pliocene epoch (3.0–3.5 Myr ago)—a period with near-modern CO₂ levels—at 255 m above present, which is validated by independent sea-level data^{6, 14, 15, 16}. Our results imply that even stabilization at today's CO₂ levels may cause sea-level rise over several millennia that by far exceeds existing long-term projections³.

1. School of Ocean and Earth Science, National Oceanography Centre, University of Southampton, Southampton SO14 3ZH, UK
2. Lamont-Doherty Earth Observatory, 61 Route 9W—PO Box 1000, Palisades, NY 10964-8000, USA
3. Institute of Geosciences, University of Tübingen, Sigwartstrasse 10, 72076, Tübingen, Germany
4. Present address: Department of Earth Science, University of Bristol, Will's Memorial Building, Queen's Road, Bristol BS8 1RJ, UK

*Correspondence, e-mail: E.Rohling@noc.soton.ac.uk

Link to abstract: http://www.nature.com/ngeo/journal/v2/n7/abs/ngeo557.html

Julian P. Sachs et al., Nature Geoscience, June 2009: Southward movement of the Pacific intertropical convergence zone AD 1400–1850

Nature Geoscience, 2 (2009) 519-525, published online 28 June 2009; doi:10.1038/ngeo554

Southward movement of the Pacific intertropical convergence zone AD 1400–1850

Julian P. Sachs^1,*, Dirk Sachse^1,4, Rienk H. Smittenberg^1,4, Zhaohui Zhang^1,4, David S. Battisti² and Stjepko Golubic³

Abstract

Tropical rainfall patterns control the subsistence lifestyle of more than one billion people. Seasonal changes in these rainfall patterns are associated with changes in the position of the intertropical convergence zone, which is characterized by deep convection causing heavy rainfall near 10^° N in boreal summer and 3^° N in boreal winter. Dynamic controls on the position of the intertropical convergence zone are debated, but palaeoclimatic evidence from continental Asia, Africa and the Americas suggests that it has shifted substantially during the past millennium, reaching its southernmost position some time during the Little Ice Age (AD 1400–1850). However, without records from the meteorological core of the intertropical convergence zone in the Pacific Ocean, quantitative constraints on its position are lacking. Here we report microbiological, molecular and hydrogen isotopic evidence from lake sediments in the Northern Line Islands, Galápagos and Palau indicating that the Pacific intertropical convergence zone was south of its modern position for most of the past millennium, by as much as 500 km during the Little Ice Age. A colder Northern Hemisphere at that time, possibly resulting from lower solar irradiance, may have driven the intertropical convergence zone south. We conclude that small changes in Earth's radiation budget may profoundly affect tropical rainfall.

1. School of Oceanography, University of Washington, Seattle, WA 98195, USA
2. Department of Atmospheric Sciences, University of Washington, Seattle, WA 98195, USA
3. Biological Science Center, Boston University, Boston, MA 02215, USA
4. Present addresses: DFG-Leibniz Center for Surface Process and Climate Studies, Institut für Geowissenschaften, Universität Potsdam, 14476 Potsdam, Germany (D.S.); Geological Institute, ETH Zürich, 8092 Zürich, Switzerland (R.H.S.); Department of Earth Sciences, Nanjing University, Nanjing, 210093, China (Z.Z.)

*Correspondence, e-mail: jsachs@u.washington.edu

Link to abstract: http://www.nature.com/ngeo/journal/v2/n7/abs/ngeo554.html

M.D. Blum, H.H. Roberts, Nature Geoscience, June 2009: Drowning of the Mississippi Delta due to insufficient sediment supply and global sea-level rise

Nature Geoscience, 2 (2009) 488-491; published online: 28 June 2009; doi:10.1038/ngeo553

Drowning of the Mississippi Delta due to insufficient sediment supply and global sea-level rise

Michael D. Blum^*,1,3 and Harry H. Roberts²

Abstract

Over the past few centuries, 25% of the deltaic wetlands associated with the Mississippi Delta have been lost to the ocean¹. Plans to protect and restore the coast call for diversions of the Mississippi River, and its associated sediment, to sustain and build new land^{2, 3}. However, the sediment load of the Mississippi River has been reduced by 50% through dam construction in the Mississippi Basin, which could affect the effectiveness of diversion plans^{4, 5, 6}. Here we calculate the amount of sediment stored on the delta plain for the past 12,000 years, and find that mean storage rates necessary to construct the flood plain and delta over this period exceed modern Mississippi River sediment loads. We estimate that, in the absence of sediment input, an additional 10,000–13,500 km² will be submerged by the year 2100 owing to subsidence and sea-level rise. Sustaining existing delta surface area would require 18–24 billion tons of sediment, which is significantly more than can be drawn from the Mississippi River in its current state. We conclude that significant drowning is inevitable, even if sediment loads are restored, because sea level is now rising at least three times faster than during delta-plain construction.

1. Department of Geology and Geophysics, Louisiana State University, Baton Rouge, LA 70803, USA
2. Coastal Studies Institute, Department of Oceanography and Coastal Sciences, Louisiana State University, Baton Rouge, LA 70803, USA
3. Present address: 11835 Memorial Drive, Houston, TX 77024, USA

Correspondence to: Michael D. Blum^1,3 e-mail: mblum@lsu.edu

Link to abstract: http://www.nature.com/ngeo/journal/v2/n7/abs/ngeo553.html

Intertropical Convergence Zone, the Earth's most prominent rainfall feature creeping northward

Earth's most prominent rainfall feature creeping northward

ScienceDaily, July 1, 2009 — The rain band near the equator that determines the supply of freshwater to nearly a billion people throughout the tropics and subtropics has been creeping north for more than 300 years, probably because of a warmer world, according to research published in the July issue of Nature Geoscience.

If the band continues to migrate at just less than a mile (1.4 km) a year, which is the average for all the years it has been moving north, then some Pacific islands near the equator – even those that currently enjoy abundant rainfall – may be drier within decades and starved of freshwater by midcentury or sooner. The prospect of additional warming because of greenhouse gases means that situation could happen even sooner.

The findings suggest "that increasing greenhouse gases could potentially shift the primary band of precipitation in the tropics with profound implications for the societies and economies that depend on it," the article says.

"We're talking about the most prominent rainfall feature on the planet, one that many people depend on as the source of their freshwater because there is no groundwater to speak of where they live," says Julian Sachs, associate professor of oceanography at the University of Washington and lead author of the paper. "In addition many other people who live in the tropics but farther afield from the Pacific could be affected because this band of rain shapes atmospheric circulation patterns throughout the world."

The band of rainfall happens at what is called the intertropical convergence zone. There, just north of the equator, trade winds from the northern and southern hemispheres collide at the same time heat pours into the atmosphere from the tropical sun. Rain clouds 30,000 ft. thick in places proceed to dump as much as 13 ft. (4 m) of rain a year in some places. The band stretching across the Pacific is generally between 3 and 10 degrees north of the equator depending on the time of year. It has recently been hypothesized that the intertropical convergence zone does not reside in the southern hemisphere for reasons having to do with the distribution of land masses and locations of major mountain ranges in the world, particularly the Andes mountains, that have not changed for millions of years.

The new article presents surprising evidence that the intertropical convergence zone hugged the equator some 350 years ago during Earth's "Little Ice Age," which lasted from 1400 to 1850.

The authors analyzed the record of rainfall in lake and lagoon sediments from four Pacific islands at or near the equator.

One of the islands they studied, Washington Island, is about 5 degrees north of the equator. Today it is at the southern edge of the intertropical convergence zone and receives nearly 10 ft. (2.9 m) of rain a year. But cores reveal a very different Washington Island in the past: It was arid, especially during the little ice age.

Among other things, the scientists looked for evidence in sediment cores of salt-tolerant microbes. On Washington Island they found that evidence in 400- to 1,000-year-old sediment underlying what is now a freshwater lake. Such organisms could only have thrived if rainfall was much reduced from today's high levels on the island. Additional evidence for changes in rainfall were provided by ratios of hydrogen isotopes of material in the sediments that can only be explained by large changes in precipitation.

Sediment cores from Palau, which lies about 7 degrees north of the equator and in the heart of the modern convergence zone, also revealed arid conditions during the Little Ice Age.

In contrast, the researchers present evidence that the Galapagos Islands, today an arid place on the equator in the Eastern Pacific, had a wet climate during the little ice age.

They write, "The observations of dry climates on Washington Island and Palau and a wet climate in the Galapagos between about 1420-1560/1640 provide strong evidence for an intertropical convergence zone located perennially south of Washington Island (5° N) during that time and perhaps until the end of the eighteenth century."

If the zone at that time experienced seasonal variations of 7 degrees latitude, as it does today, then during some seasons it would have extended southward to at least the equator, Sachs says. This has been inferred previously from studies of the intertropical convergence zone on or near the continents, but the new data from the Pacific Ocean region is clearer because the feature is so easy to identify there.

The remarkable southward shift in the location of the intertropical convergence zone during the little ice age cannot be explained by changes in the distribution of continents and mountain ranges because they were in the same places in the little ice age as they are now. Instead, the co-authors point out that the Earth received less solar radiation during the little ice age, about 0.1% less than today, and speculate that may have caused the zone to hover closer to the equator until solar radiation picked back up.

"If the intertropical convergence zone was 550 km, or 5 degrees, south of its present position as recently as 1630, it must have migrated north at an average rate of 1.4 km – just less than a mile – a year," Sachs says. "Were that rate to continue, the intertropical convergence zone will be 126 km – or more than 75 miles – north of its current position by the latter part of this century."

Link: http://www.sciencedaily.com/releases/2009/07/090701135535.htm

Sea level rise: It's worse than we thought

by Anil Ananthaswamy, New Scientist, July 1, 2009

FOR a few minutes David Holland forgets about his work and screams like a kid on a roller coaster. The small helicopter he's riding in is slaloming between towering cliffs of ice -- the sheer sides of gigantic icebergs that had calved off Greenland's Jakobshavn glacier. "It was like in a James Bond movie," Holland says afterwards. "It's the most exciting thing I have ever done."

Jakobshavn has doubled its speed in the past 15 years, draining increasing amounts of ice from the Greenland ice sheet into the ocean, and Holland, an oceanographer at New York University, has been trying to find out why. Scientists like him are more than a little astonished at the rate at which our planet's frozen frontiers seem to be responding to global warming. The crucial question, though, is what will happen over the next few decades and centuries.

That's because the fate of the planet's ice, from relatively small ice caps in places like the Canadian Arctic, the Andes and the Himalayas, to the immense ice sheets of Greenland and Antarctica, will largely determine the speed and extent of sea level rise. At stake are the lives and livelihoods of hundreds of millions of people, not to mention millions of square kilometres of cities and coastal land, and trillions of dollars in economic terms.

In its 2007 report, the Intergovernmental Panel on Climate Change (IPCC) forecast a sea level rise of between 19 and 59 centimetres by 2100, but this excluded "future rapid dynamical changes in ice flow." Crudely speaking, these estimates assume ice sheets are a bit like vast ice cubes sitting on a flat surface, which will stay in place as they slowly melt. But what if some ice sheets are more like ice cubes sitting on an upside-down bowl, which could suddenly slide off into the sea as conditions get slippery? "Larger rises cannot be excluded but understanding of these effects is too limited to assess their likelihood," the IPCC report stated.

Even before it was released, the report was outdated. Researchers now know far more. And while we still don't understand the dynamics of ice sheets and glaciers well enough to make precise predictions, we are narrowing down the possibilities. The good news is that some of the scarier scenarios, such as a sudden collapse of the Greenland ice sheet, now appear less likely. The bad news is that there is a growing consensus that the IPCC estimates are wildly optimistic.

The oceans are already rising. Global average sea level rose about 17 cm in the 20th century, and the rate of rise is increasing. The biggest uncertainty for those trying to predict future changes is how humanity will behave. Will we start to curb our emissions of greenhouse gases sometime soon, or will we continue to pump ever more into the atmosphere?

Even if all emissions stopped today, sea level would continue to rise. "The current rate of rise would continue for centuries if temperatures are constant, and that would add about 30 cm per century to global sea level," says Stefan Rahmstorf of the Potsdam Institute for Climate Impact Research in Germany. "If we burn all fossil fuels, we are likely to end up with many metres of sea level rise in the long run, very likely more than 10 m in my view."

This might sound dramatic, but we know sea level has swung from 120 m lower than today during ice ages to more than 70 m higher during hot periods. There is no doubt at all that if the planet warms, the sea will rise. The key questions are, by how much and how soon?

To pin down the possibilities, researchers have to look at what will happen to all the different contributors to sea level under various emissions scenarios. The single biggest contributor to sea level rise over the past century has been the melting of glaciers and ice caps outside of Greenland and Antarctica, from Alaska to the Himalayas. According to one recent estimate, the continued loss of this ice will add another 10-20 cm to sea level by 2100. It cannot get much worse than this: even if all this ice melted, sea level would only rise by about 33 cm.

Expanding waters

The second biggest contributor has been thermal expansion of the oceans. Its future contribution is relatively simple to predict, as we know exactly how much water expands for a given increase in temperature. A study published earlier this year found that even if all emissions stopped once carbon dioxide levels hit 450 parts per million (ppm) -- an unrealistically optimistic scenario -- thermal expansion alone would cause sea level to rise by 20 cm by 2100, and by another 10 cm by 3000. At the other extreme, if emissions peak at 1200 ppm, thermal expansion alone would lead to a 0.5-m rise by 2100, and another 1.4 m by 3000 (see "How high, how soon?").

Then there are the great ice sheets of Greenland and Antarctica, which hold enough water to raise sea level by about 70 metres. Until recently, their contribution to sea level rise was negligible, and the IPCC predicted that Greenland would contribute 12 cm at most to sea level rise by 2100, while Antarctica would actually gain ice overall due to increased snowfall. "A lot of new results have been published since then to show that this very conservative conclusion does not hold," says Eric Rignot of the University of California, Irvine.

To study the ice sheets, Rignot and colleagues have combined satellite-based radar surveys, aircraft altimetry and gravity measurements using NASA's GRACE satellite. They found that ice loss is increasing fast. Greenland is now losing about 300 gigatonnes of ice per year, enough to raise sea level by 0.83 mm. Antarctica is losing about 200 gigatonnes per year, almost all of it from West Antarctica and the Antarctic Peninsula, raising levels by 0.55 mm. "The mass loss is increasing faster than in Greenland," Rignot says. "It'll overtake Greenland in years to come."

If this trend continues, Rignot thinks sea level rise will exceed 1 metre by 2100. So understanding why Greenland and Antarctica are already losing ice faster than predicted is crucial to improving our predictions.

The main reason for the increase is the speeding up of glaciers that drain the ice sheets into the sea. One cause is the knock-on effect of warmer air melting the surface of the ice: when the surface ice melts, the water pours down through crevasses and moulins to the base of glaciers, lubricating their descent into the sea. Fears about the impact of this phenomenon have receded somewhat, though: Antarctica is thought to be too cold for it to be a big factor, and even in Greenland it is only a summertime effect. "It's significant, but I don't think it's the primary mechanism that would be responsible for dramatic increases in sea level," says glaciologist Robert Bindschadler at the NASA Goddard Space Flight Center in Greenbelt, Maryland.

There is another way for surface melt to affect sea level, though. Meltwater fills any crevasses, widening and deepening the cracks until they reach all the way down to the base of the ice. This can have a dramatic effect on floating ice shelves. "Essentially, you are chopping up an ice shelf into a bunch of tall thin icebergs, like dominoes standing on their ends," says Bindschadler. "And they are not very stable standing that way." They fall over, and push their neighbours out to sea.

The most famous break-up in recent times -- that of the Larsen B ice shelf on the Antarctic Peninsula in 2002 -- likely happened this way. While the break-up of floating ice shelves does not raise sea level directly, the disintegration of Larsen B had consequences that models at the time failed to predict. With little to resist their advance, glaciers behind Larsen B immediately began to move up to eight times faster. Five smaller ice shelves in the rapidly warming Antarctic Peninsula have also broken up and many others are disintegrating.

What lies beneath

Surface melt poses little threat in West Antarctica, as it is so much colder. Here the danger comes from below. Take the ice shelf holding back the massive Pine Island glacier, which is thinning in a strange pattern. Radar scans have revealed giant "ripples" up to 100 m deep on its underside.

Bindschadler thinks that the currents created by winter winds raise relatively warm water from a few hundred metres down in the Amundsen Sea off West Antarctica. This melts the underside of the ice shelf and gets trapped in the space it carves out, thus continuing to melt the ice from below over a few seasons. As the ice shelf thins, the Pine Island glacier behind it is speeding up, from 3 km/year, three years ago, to over 4 km/year according to the latest unpublished measurements by Ian Joughin of the University of Washington in Seattle.

What does this have to do with global warming? Climate change, aided and abetted by the loss of ozone, has strengthened the winds that circle Antarctica. This is speeding up the Antarctic circumpolar current and pushing surface waters away from the coast, causing deeper, warmer water to well up.

Along with the Thwaites glacier and some smaller ones, Pine Island glacier drains a third of the West Antarctic ice sheet. This ice sheet is particularly vulnerable to ocean heat because much of it rests on the seabed, a kilometre or more below sea level. This submarine ice will not raise sea level if it melts, but if it goes a lot of higher-level ice will end up in the ocean. The vulnerable parts contain enough ice to raise sea level 3.3 m -- less than the 5 m that was once estimated but more than enough to have catastrophic effects.

Bindschadler has calculated that a change in ocean currents could potentially deliver up to 10¹⁹ joules of heat per year to the continental shelf off West Antarctica -- and only about 10⁹ joules per year would be required to melt the ice shelves that hold back the Pine Island and Thwaites glaciers. "The ocean has an enormous amount of heat compared to the atmosphere," he says.

Even in Greenland, where the ice sheet rests on land above sea level, ocean heat still matters. When not dodging giant icebergs, Holland has been trying to find out why Greenland's Jakobshavn glacier started moving faster in 1997, speeding up from around 6 km/year to more than 9 km/year by 2000 and 13 km/year by 2003. The glacier continues to drain ice from the Greenland ice sheet at a higher rate than before.

The increase had been attributed to lubrication by meltwater, but Holland's team recently stumbled across data from local fishing boats, which deploy thermometers in bottom-trawling nets. One fact stood out: the temperature of the subsurface waters around West Greenland jumped in 1997, prior to the massive calving of Jakobshavn.

As the team reported last year, though, the real trigger lay in what happened in 1996. That year, the winds across the North Atlantic weakened, slowing down the warm Gulf Stream. The weakened current meandered aimlessly and hit west Greenland. "A modest change in wind gives you a big bang in terms of ice sheet dynamic response," says Holland.

Findings like these suggest that predicting sea level rise is even trickier than previously thought. If relatively small changes in winds and currents could have a big impact on ice sheets, we need extremely good models of regional climate as well as of ice sheets. At the moment we have neither -- and while regional climate models are improving, ice sheet models are still too crude to make accurate predictions.

"They are coarse models that don't include mechanisms that allow glaciers to speed up," says Rignot. "And what we are seeing today is that this is not only a big missing piece, this could be the dominant piece. We can't really afford to wait 10 to 20 years to have good ice sheet models to tell people, 'Well, sea level is actually going to rise 2 metres and not 50 centimetres', because the consequences are very significant, and things will be pretty much locked in at that point."

So climate scientists are looking for other ways to predict sea level rise. Rahmstorf, for instance, is treating the Earth as one big black box. His starting point is the simple idea that the rate of sea level rise is proportional to the increase in temperature: the warmer Earth gets, the faster ice melts and the oceans expand. This held true for the last 120 years at least. "There is a very close and statistically highly significant correlation between the rate of sea level rise and the temperature increase above the pre-industrial background level," says Rahmstorf.

Extrapolating this to the future, based on IPCC emissions scenarios, suggests sea level will rise by between 0.5 and 1.4 m -- and the higher estimate is more likely because emissions have been rising faster than the IPCC's worst-case scenario. Rahmstorf's study got a mixed reception when it first appeared, but he can feel the winds of change. "I sense that now a majority of sea level experts would agree with me that the IPCC projections are much too low," he says.

Could even Rahmstorf's estimate be too low? It assumes the relation between temperature and sea level is linear, but some experts, most prominently James Hansen of NASA's Goddard Institute for Space Studies in New York, argue that because there are multiple positive feedbacks, such as the lubrication of glaciers by meltwater, higher temperatures will lead to accelerating ice loss. "Why do I think a sea level rise of metres would be a near certainty if greenhouse gas emissions keep increasing?" Hansen wrote in New Scientist (28 July 2007, p 30). "Because while the growth of great ice sheets takes millennia, the disintegration of ice sheets is a wet process that can proceed rapidly."

Hansen has made no specific prediction, however. So just how bad could it get? Tad Pfeffer of the University of Colorado in Boulder decided to work backwards from some of the worst-case scenarios: 2 m by 2100 from Greenland, and 1.5 m from West Antarctica, via the Pine Island and Thwaites glaciers. Just how fast would the glaciers have to be moving for the sea level to rise by these amounts? Pfeffer found that glaciers in Greenland would need to move at 70 km/year, and Pine Island and Thwaites glaciers at 50 km/year, from now until 2100. Since most glaciers are moving at just a few kilometres per year, to Pfeffer and many others, these numbers seem highly unrealistic.

Worst case

So what is possible? For scenarios based on conservative assumptions, such as a doubling of glacier speeds, Pfeffer found sea level will rise by around 80 cm by 2100, including thermal expansion. "For the high end, we took all of the values we could change and we pushed them forward to the largest numbers we imagined would be reasonable," says Pfeffer. The answer: 2 metres.

These estimates fit well with recent studies of comparable periods in the past, which have found that sea level rise averaged up to 1.6 m per century at times. There is a huge caveat in Pfeffer's number crunching, though. "An important assumption we made is that the rest of West Antarctica stays put. And this is the part of West Antarctica that is held behind the Ross ice shelf and the Ronne ice shelf," says Pfeffer. "Those two ice shelves are very big, and very thick, and very cold. We don't see a way to get rid of those in the next century."

Holland is not so sure. He has been studying computer models of ocean currents around Antarctica, and he doesn't like what he sees. The subsurface current of warm water near the frozen continent, known as the circumpolar deep water, branches near the coast, and one branch hits Pine Island -- which is probably why the ice there is thinning and speeding up. "Another branch of it comes ever so close to the Ross ice shelf," says Holland. "In some computer simulations of the future, the warm branch actually goes and hits Ross."

While it is impossible to predict exactly what will cause this, the lessons from Jakobshavn show that a small change in the wind patterns over Antarctica might be enough to shift the warm current towards and eventually underneath the Ross ice shelf. Then even this gigantic mass of ice -- about the size of France -- becomes vulnerable, regardless of how cold the air above it is. Pfeffer agrees that the Ross and Ronne ice shelves are the wild cards. "If we pull the plug on those two, then we create a very different world."

Is there really a danger of a collapse, which would cause a sudden jump in sea levels? Paul Blanchon's team at the National Autonomous University of Mexico in Cancun has been studying 121,000-year-old coral reefs (pictured above) in the Yucatan Peninsula, formed during the last interglacial period when sea level peaked at around 6 ms higher than today. His findings suggest that at one point the sea rose 3 m within 50-100 years.

We just don't know if this could happen again in the 21st century. What is clear, though, is that even the lowest, most conservative estimates are now higher than the IPCC's highest estimate. "Most of my community is comfortable expecting at least a metre by the end of this century," says Bindschadler.

Most glaciologists who study Greenland and Antarctica are expecting at least a metre rise by the end of the century

And it will not stop at a metre. "When we talk of sea level rising by 1 or 2 metres by 2100, remember that it is still going to be rising after 2100," Rignot warns.

All of which suggests we might want to start preparing. "People who are trying to downplay the significance say, 'Oh, the Earth has gone through changes much greater than this, you know, in the geological past'," says Pfeffer. "That's true, but it's completely irrelevant. We weren't there then."

What it all means

If a one-metre rise in sea level doesn't sound like much, consider this: about 60 million people live within one metre of mean sea level, a number expected to grow to about 130 million by 2100.

Much of this population lives in the nine major river deltas in south and southeast Asia. Parts of countries such as Bangladesh, along with some island nations like the Maldives, will simply be submerged.

According to a 2005 report, a one-metre rise in sea level will affect 13 million people in five European countries and destroy property worth $600 billion, with the Netherlands the worst affected. In the UK, existing defences are insufficient to protect parts of the east and south coast, including the cities of Hull and Portsmouth.

Besides inundation, higher seas raise the risk of severe storm surges and dangerous flooding. The entire Atlantic seaboard of North America, including New York, Boston and Washington DC, and the Gulf coast will become more vulnerable to hurricanes. Today's 100-year storm floods might occur as often as every four years -- in which case it will make more sense to abandon devastated regions and towns than to keep rebuilding them.

Anil Ananthaswamy is a contributing editor for New Scientist

Link: http://www.newscientist.com/article/mg20327151.300-sea-level-rise-its-worse-than-we-thought.html?full=true

Arctic Sea Ice Conditions, July 4, 2009 -- just getting worse, day by day

CLICK ON ANY IMAGE TO ENLARGE THE DETAILS

From the Cryosphere Today, image of July 4th, 2009:


From the Canadian Met Office, satellite image from July 5th, 2009:


From the National Snow and Ice Data Center, the Arctic sea ice extent graph (remember, even though the curve is following the curve for 2007, the ice is probably half as thick as it was in that year):

Pep Canadell: Amount of carbon stored in soils surrounding the North Pole has been hugely underestimated

Permafrost melting a growing climate threat

SINGAPORE, July 1, 2009 (Reuters) -- The amount of carbon locked away in frozen soils in the far Northern Hemisphere is double previous estimates and rapid melting could accelerate global warming, a study released on Wednesday says.

Large areas of northern Russia, Canada, Nordic countries and the U.S. state of Alaska have deep layers of frozen soil near the surface called permafrost.

Global warming has already triggered rapid melting of the permafrost in some areas, releasing powerful greenhouse gases carbon dioxide and methane.

As the world gets warmer, more of these gases are predicted to be released and could trigger a tipping point in which huge amounts of the gases flood the atmosphere, rapidly driving up temperatures, scientists say.

"Massive amounts of carbon stored in frozen soils at high latitudes are increasingly vulnerable to exposure to the atmosphere," said Pep Canadell, executive director of the Global Carbon Project at Australia's state-funded Commonwealth Scientific and Industrial Research Organisation.

"The research shows that the amount of carbon stored in soils surrounding the North Pole has been hugely underestimated."

The study is published in the latest issue of Global Biogeochemical Cycle.

Canadell said a four-year study of the latest research on permafrost, data from new drilling projects as well as the release of previously unpublished data from the Russian Academy of Sciences had led to a rethink of carbon levels.

"Projections show that almost all near-surface permafrost will disappear by the end of this century exposing large carbon stores to decomposition and release of greenhouse gases," he said in a statement.

He said if only 10% of the permafrost melted, this could lead to the release of an additional 80 ppm of carbon dioxide equivalent into the atmosphere. This would equate to about 0.7 °C of global warming.

According to the U.N. Climate Panel, average temperatures have already risen by about 0.7 °C since the late nineteenth century and are forecast to rise another 1.8-4 °C by 2100, Scientists say a rapidly warming planet will trigger more intense storms and droughts, rising seas and melting ice caps.

Canadell said that on a recent trip to northern China, the permafrost at its southern limit had all but disappeared over the past 20 years.

Locals had told him the permafrost was once 20 cm below the surface, and now it was several metres down, he told Reuters from Canberra, Australia.

In the statement, he said computer models showed global warming could trigger an irreversible process of thawing.

For example, heat generated from increased microbial activity in the soil could lead to sustained and long-term emissions of carbon dioxide and methane.

In addition, lakes formed as permafrost thaws would draw heat to deeper layers and bring methane trapped in pockets below to the surface. (Reporting by David Fogarty; editing by Jerry Norton.)
Link: http://www.reuters.com/article/africaCrisis/idUSSP458218

South Korea pays zero for leasing one-half of Madagascar's arable land for 99 years

Madagascar: South Korean Land Deal Sparks Controversy

[Hat tip to New York Times environmental journalist, Andrew Revkin, for pointing me in the direction of this article. Mr. Revkin's blog at the New York Times -- Dot Earth -- can be accessed at this link: http://dotearth.blogs.nytimes.com/]

by Lova Rakotomalala, globalvoicesonline.org, November 23, 2008

South Korea has just leased half of all the arable land in Madagascar according to the Financial Times. This has stirred quite a debate in the Malagasy blogosphere about land sovereignty and economic development. It is still unclear whether the land deal has actually been signed by both parties. Meanwhile, bloggers are arguing whether this sort of deal should be considered “neo-colonialism.”

Here is an overview of what is know so far.

On November 19, the Financial Times reported on the deal between South Korean company Daewoo Logistics and the Malagasy government.

On the Global Dashboard blog, Alex Evans summarizes the findings:

South Korea has just struck a 99 year deal with Madagascar to lease an area half the size of Belgium to grow palm oil and no less than half of South Korea’s corn demands [..] Carl Atkins, of consultants Bidwells Agribusiness, said Daewoo Logistics' investment in Madagascar was the largest it had seen. “The project does not surprise me, as countries are looking to improve food security but its size it does surprise me.”

A few hours later, a follow-up article in the Financial Times added that Daewoo Logistics would not have to pay fees for the lease, but would instead provide the means to allow exploitation and development of the land.

Alex Evans, quoting from the second article, says it's even worse news than he thought:

A few hours later, a truly astonishing new angle on the story emerged. Guess how much South Korea had paid for its 99 year lease? Answer: Zip. Zero. Nada. Not a cent. The sum total of the benefits for Madagascar, according to a Daewoo spokesman? “We will provide jobs for them by farming it, which is good for Madagascar.” This in a country where 3.5% of people are on WFP food aid…
The benefits for South Korea, on the other hand:

“We want to plant corn there to ensure our food security. Food can be a weapon in this world,” said Hong Jong-wan, a manager at Daewoo. “We can either export the harvests to other countries or ship them back to Korea in case of a food crisis.”

Photo by Foko-Madagascar

The Malagasy government has yet to release an official statement on the issue. Reuters reports that the deal is far from being finalized. Daewoo Logistics, however, has issued several statements that contest the veracity of the articles.

Robert Koelher, blogging from Seoul at The Marmot’s Hole, explains the points of contentions from the South Korean company:

In another report, the Maeil Gyeongje said experts believe the FT report, with its provocative talk of “neo-colonialism” and “pirates,” was intended as a warning against an increased Asian presence in Africa, long considered Europe’s backyard. The piece did include a quote from a Daewoo Logistics official, however, who said Madagascar was quite sensitive about this issue because when China invests, it only goes after its own profits [..]
The JoongAng Ilbo, meanwhile, released an editorial blasting the FT, asking why the paper was turning a blind eye to British Jatropha farms in Madagascar (used for biodiesel fuel) and French plantations on the island while going after a Korean company only. And besides, the land Daewoo is acquiring is undeveloped, the new farms will provide employment, and the Madagascar government will be taking a 30% cut of the farm profits in taxes.”

Reactions to news of the land deal were heated and diverse in the Malagasy blogosphere:

The Malagasy diaspora website Sobika reported on the deal (Fr) moments after the Financial Times and asked their readers to react. Over 100 comments were posted on the articles within a few days. In a follow-up article, Sokiba speculates that the outrage expressed on the internet has led the company deny the conditions of the deal [Fr].

The outrage is far from being unanimous though. Some bloggers feel that the land deal could benefit Madagascar by increasing productivity on parts of the land. Aiky on the community blog Malagasy Miray adds:

The advantages as seen from a less emotional perspective:

- The new employment prospects for the farmers which in turn would lead to additional source of revenues.
- The exploitation of lands that were thought to be of little value and that could be still exploited after the lease.
- the chain reaction from such increase in revenues [..]
- the potential improvement in the status of the national roads and other facilities in that part of the country.
- A possible incentive to stop the exodus from the rural areas

On The Cyber Observer, a lawyer and blogger in Antananarivo, Andrydago, had the the amazing foresight to raise the legal issue of the sovereignty of land and foreign investment in October, a full month before this controversy. It is striking that the laws that make this lease permissible were amended earlier this year:

Recently, the new Malagasy investment law: act 2007-036 of January 14th, 2008, has brought a very key change concerning the possibility for foreigners to own their land in Madagascar. This law provided that foreign companies or foreign investors (individuals who have been granted with investor visa), can buy Malagasy land under the following conditions:

1. the land has to be used exclusively for professional exploitation. Any personal use and exploitation which is different from the nature of exploitation he “promised” to the Malagasy government, are forbidden. If there is a breach of such condition, the government can legally withdraw its title of land ownership;

2. the foreign company or investor has to submit its business plan (investment planning in Madagascar) to a public body named EDBM (Economic Development Board Madagascar). Such plan has to describe and detail its intended business and its pertaining investment in Madagascar;

3. the foreign company or investor has to apply for a formal approval named “authorization for land acquisition” before the EDBM in order to be allowed to purchase legally a Malagasy land. Such authorization if granted, gives to the foreign company or investor the same rights as for a Malagasy entity to purchase and to own land in Madagascar.

Link to article: http://globalvoicesonline.org/2008/11/23/madagascar-south-korean-land-deal-sparks-controversy/

Andrew Revkin's article:

March 25, 2009, 2:11 pm

Madagascar’s Turmoil Spills Into Forests

By Andrew C. Revkin

A host of reports from Madagascar indicate that environmental turmoil, including raids on parks for rosewood, is rising in the wake of political upheaval in that remarkable island nation, which is home to hundreds of extraordinary animal and plant species.

Mireya Mayor, an “emerging explorer” for National Geographic, has a detailed post on the NatGeo News Watch blog providing great background on how political instability has intensified environmental problems. In an e-mail last week, she described her decade of work there, in which she focused on several severely endangered primates, including the silky sifaka, which is restricted to the Marojejy National Park and surrounding regions. That park, she said, is now being invaded by loggers and its director has been threatened.

Here’s some video showing the sifaka:

Madagascar’s president was driven from office last week after waves of protests and violence that may have been triggered by the purchase of a presidential jet and a plan for South Korea to lease huge tracts in Madagascar for agriculture.

Dr. Mayor pointed me to the excellent Web site of the Marojejy park, which includes a slide show of some of the threats to the ecosystems, ranging from poaching to illegal logging. More background is at Mongabay.com.

This seems to be a prime example of a pattern described in a recent paper on conflicts in regions rich in biological diversity.

With human populations and appetites on the rise, and as regions with untrammeled biological bounty get ever more restricted, I don’t imagine this pattern is going to fade any time soon.

Link to Andrew Revkin's column: http://dotearth.blogs.nytimes.com/2009/03/25/madagascars-turmoil-spills-into-forests/

India, China, Saudi Arabia buying up resources, arable land in poorer countries and Brazil, Russia, Ukraine

Fears for the world's poor countries as the rich grab land to grow food

• UN sounds warning after 30m hectares bought up
• G8 leaders to discuss 'neo-colonialism'

by John Vidal, The Guardian, July 3, 2009

The acquisition of farmland from the world's poor by rich countries and international corporations is accelerating at an alarming rate, with an area half the size of Europe's farmland targeted in the last six months, reports from UN officials and agriculture experts say.

New reports from the UN and analysts in India, Washington and London estimate that at least 30m hectares is being acquired to grow food for countries such as China and the Gulf states who cannot produce enough for their populations. According to the UN, the trend is accelerating and could severely impair the ability of poor countries to feed themselves.

Today it emerged that world leaders are to discuss what is being described as "land grabbing" or "neo-colonialism" at the G8 meeting next week. A spokesman for Japan's ministry of foreign affairs confirmed that it would raise the issue: "We feel there should be a code of conduct for investment in farmland that will be a win-win situation for both producing and consuming countries," he said.

Olivier De Schutter, special envoy for food at the UN Office of the High Commissioner for Human Rights, said: "[The trend] is accelerating quickly. All countries observe each other and when one sees others buying land it does the same."

The UN's food and agricultural organisation and other analysts estimate that nearly 20m hectares (50m acres) of farmland – an area roughly half the size of all arable land in Europe – has been sold or has been negotiated for sale or lease in the last six months. Around 10m hectares was bought last year. The land grab is being blamed on wealthy countries with concerns about food security.

Some of the largest deals include South Korea's acquisition of 700,000ha in Sudan, and Saudi Arabia's purchase of 500,000ha in Tanzania. The Democratic Republic of the Congo expects to shortly conclude an 8m-hectare deal with a group of South African businesses to grow maize and soya beans as well as poultry and dairy farming.

India has lent money to 80 companies to buy 350,000ha in Africa. At least six countries are known to have bought large landholdings in Sudan, one of the least food-secure countries in the world.

Other countries that have acquired land in the last year include the Gulf states, Sweden, China and Libya. Those targeted include not only fertile countries such as Brazil, Russia and Ukraine, but also poor countries like Cameroon, Ethiopia, Madagascar, and Zambia.

De Schutter said that after the food crisis of 2008, many countries found food imports hit their balance of payments, "so now they want to insure themselves."

"This is speculation, betting on future prices. What we see now is that countries have lost trust in the international market. We know volatility will increase in the next few years. Land prices will continue to rise. Many deals are even now being negotiated. Not all are complete yet."

He said that about one-fifth of the land deals were expected to grow biofuel crops. "But it is impossible to know with certainty because declarations are not made as to what crops will be grown," he said.

Some of the world's largest food, financial and car companies have invested in land.

Alpcot Agro of Sweden bought 120,000ha in Russia, South Korea's Hyundai has paid $6.5m (£4m) for a majority stake in Khorol Zerno, which owns 10,000ha in Eastern Siberia, while Morgan Stanley has bought 40,000ha in Ukraine. Last year South Korea's Daewoo signed a 99-year lease for 1.3m hectares of agricultural land in Madagascar.

Devinder Sharma, analyst with the Forum for Biotechnology and Food Security in India, predicted civil unrest.

"Outsourcing food production will ensure food security for investing countries but would leave behind a trail of hunger, starvation and food scarcities for local populations," he said. "The environmental tab of highly intensive farming – devastated soils, dry aquifer, and ruined ecology from chemical infestation – will be left for the host country to pick up."

In Madagascar, the Daewoo agreement was seen as a factor in the subsequent uprising that led to the ousting of the president, Marc Ravalomanana. His replacement, Andry Rajoelina, immediately moved to repeal the deal.

Concern is mounting because much of the land has been targeted for its good water supplies and proximity to ports. According to a report last month by the London-based International Institute for Environment and Development, the land deals "create risks and opportunities."

"Increased investment may bring benefits such as GDP growth and improved government revenues, and may create opportunities for economic development and livelihood improvement. But they may result in local people losing access to the resources on which they depend for their food security – particularly as some key recipient countries are themselves faced with food security challenges," said the authors.

According to a US-based thinktank, the International Food Policy Research Institute, nearly $20bn to $30bn a year is being spent by rich countries on land in developing countries.

Link: http://www.guardian.co.uk/environment/2009/jul/03/land-grabbing-food-environment

Why climate change deniers love to hear they are committing treason

They love to see themselves as brave victims of McCarthyism, standing up against a wave of pseudo-scientific indoctrination

by Leo Hickman, The Guardian, July 1, 2009

Strong words from Paul Krugman, the Nobel-prize winning Princeton economist, in his column for the New York Times this week. After watching the debate in the House of Representatives last week before the vote on the Waxman-Markey climate-change bill, Krugman said he was appalled by the claims made by some of the climate change deniers who reside within the Grand Old Party.

As I watched the deniers make their arguments, I couldn't help thinking that I was watching a form of treason – treason against the planet … If you watched the debate on Friday, you didn't see people who've thought hard about a crucial issue, and are trying to do the right thing. What you saw, instead, were people who show no sign of being interested in the truth. They don't like the political and policy implications of climate change, so they've decided not to believe in it – and they'll grab any argument, no matter how disreputable, that feeds their denial.

One sight in particular seemed to rile Krugman: representative Paul Broun of Georgia standing before the floor and grandly stating that the climate change "hoax" has been "perpetrated out of the scientific community." What's more, his statement generated a somewhat stilted ripple of applause, as can be seen on this YouTube clip. Broun's views on climate change have been aired before – he has renamed the Waxman-Markey bill on his Twitter feed [6] as the "Wacky-Marxist Tax and Cap Bill" – but to find this sort of crackpot denial being aired in the House ahead of a pivotal vote, as opposed to in some dark corner of the internet, left Krugman angry:

Is it fair to call climate denial a form of treason? Isn't it politics as usual? Yes, it is – and that's why it's unforgivable. Do you remember the days when Bush administration officials claimed that terrorism posed an "existential threat" to America, a threat in whose face normal rules no longer applied? That was hyperbole – but the existential threat from climate change is all too real. Yet the deniers are choosing, willfully, to ignore that threat, placing future generations of Americans in grave danger, simply because it's in their political interest to pretend that there's nothing to worry about. If that's not betrayal, I don't know what is.

Krugman is not the first person to raise the spectre of climate change denial being an actionable crime. Mark Lynas, for example, has speculated in the past about "what sentences judges might hand down at future international criminal tribunals on those who will be partially but directly responsible for millions of deaths from starvation, famine and disease in decades ahead." James Hansen has also argued that the chief executives of large fossil fuel companies that actively spread doubt about climate change should be put on trial for "crimes against humanity and nature".

The deniers love this sort of attack, of course. It steels them to hear accusations that they are committing "thought crimes," or "treason" no less. They love to see themselves as brave, "truth"-wielding Galileos standing up against a wave of pseudo-scientific indoctrination. They trot out the predictable comparisons to the Salem witch trials and McCarthyism. It all helps to feed into their grand conspiracy theory that climate change is, indeed, a big lefty hoax dreamt up solely to squeeze more taxes out of us all.

You can't help conclude that we're heading for one hell of a day of reckoning with all this. Someone's going to lose spectacularly big in this particular culture war. I certainly know where my money is, but the sad thing is the bragging rights will be irrelevant given the reality of what will be going on outside our windows. If only it were true that all that was at stake was a debating society trophy.

Link: http://www.guardian.co.uk/environment/blog/2009/jul/01/climate-change-denier-treason

Melting Arctic is releasing vast quantities of methane

The Arctic Thaw Could Make Global Warming Worse

The melting Arctic is releasing vast quantities of methane. How big is this greenhouse threat? What can be done?

by Sarah Simpson, Scientific American, June 2009
Research Pioneer: Katey Walter captures methane rising from a thawing lake bottom in Alaska. Photo by Doug Wiseman

A young scientist with curly, reddish hair tucked beneath a knit cap stepped gingerly onto the three-day-old ice of a remote lake in northeastern Siberia. Coating the black depths like cellophane, the thin film held no promise to bear her weight, but a sudden dunk in the frigid water was a risk she had to take. Searching the lake by rickety rowboat all summer had failed, and any day winter’s first big snow would engulf the region, obscuring the lake’s surface until spring. She could not afford to wait that long.

The woman shivered in her worn, blue down jacket and glanced up at the overcast sky. After one more cautious step, she spotted her quarry: a cluster of platter-size bubbles frozen into the ice. Those pockets of gas, which had risen from thawing permafrost—formerly frozen soil—at the lake’s bottom, were the aim of her doctoral research. Long elusive, they suddenly stood out like white stars against a night sky, though less serenely. With a small pick she cracked the icy skin of one of the bubbles and remained unfazed when it hissed back like a punctured gas pipe. Leaning forward, she apprehensively struck a match just above the broken bubble and flames as high as her head burst skyward. The flammable substance was methane, a greenhouse gas that could cause more global warming than carbon dioxide (CO₂).

Today, nearly seven years after igniting that first bubble, Katey Walter finds herself center stage in an environmental drama playing out across the frozen north. Now a 33-year-old assistant professor at her alma mater, the University of Alaska–Fairbanks, Walter was the first to explain the mysterious methane emissions from Arctic lakes. She isn’t shy about touting their significance as a ticking time bomb. In a complete Arctic thaw, these lakes could discharge a whopping 50 billion tons of methane: 10 times the amount already helping to heat the planet.

Whether a total or more moderate release is in store is still anyone’s guess. But pound for pound, methane in the atmosphere traps 25 times more of the sun’s heat than CO₂ does. Consequently, even a modest thaw of the perennially frozen soil that lies under these ephemeral lakes and caps the dry land around them could trigger a vicious cycle: warming releases methane and creates lakes, which thaw permafrost and liberate more gas, which intensifies warming, which creates more lakes, and so on. Some Arctic lakes are growing larger, and researchers are eyeing them suspiciously as a reason why global methane concentrations shot up in 2007 and have stayed high ever since. Other signs indicate that permafrost thawing on the Arctic seafloor may be loosening the cap on large pockets of methane stored deeper down.

Walter is sounding the alarm even louder than before because global warming is taking a special toll across the far north. The region is heating up twice as quickly as the rest of the globe, rapidly melting sea ice in the Arctic Ocean as well as the permafrost, which underlies 8.8 million square miles of the Northern Hemisphere. Leading climate models already suggest greenhouse warming as a result of most of the Arctic’s permafrost thawing by 2100—and the estimates do not yet include the potentially vast additional warming imparted by methane bubbling up out of chilly waters. Walter and others are trying to determine just how much methane could be released into the atmosphere, how soon, how aggressively that release would accelerate the earth’s warming and whether anything can be done to temper the escalating threat.

Burps and Belches
Scientists know with great certainty how much methane is in the earth’s atmosphere at any given time from sampling its concentration weekly at dozens of sites worldwide. By plugging these measurements into global climate models, they know methane is responsible for a third of the current warming trend. Exactly how much gas comes from where is harder to say, which is why the Arctic lake bubbles were so long overlooked.

Methane is emitted anywhere organic matter ferments—be that a cow’s belly or frozen soil that starts to thaw. Permafrost, which averages 80 feet thick, is chock-full of dead plant and animal matter that has been locked in cold storage for thousands of years. Conventional wisdom long held that permafrost should take thousands of years to melt away, so researchers expected it to play a negligible role in climate change. But recent findings—Walter’s lake discovery in particular—have wrecked that prediction.

Walter’s work revealed that the relatively warm lake bed was indeed thawing the frozen earth directly below it, down several dozen feet. Thawing a block of permafrost is like taking a package of frozen hamburger out of the freezer and leaving it on the kitchen counter. As the meat warms, ravenous microbes consume it, giving off a gas as a by-product. On dry land, microbes convert the dead animal and plant matter primarily into CO₂. But in the wet, oxygen-starved depths of a lake, they instead release methane. Walter’s best guess is that researchers have been underestimating methane emissions from Arctic wetlands by as much as 63 percent.

This methane alert, which Walter raised first in her doctoral thesis, captured the attention of the U.S. Council of Graduate Schools, which in 2006 granted her the nation’s most prestigious honor for doctoral dissertations. She credits her discovery to living lakeside from one season to the next. Most scientists tend to be in the field only during the summer, when the bubbling seeps of gas are hard to spot in open water, or in the winter, when the lake is buried under six feet of snow. The same camouflage deterred Walter until that overcast afternoon in October 2002, when she decided to remain lakeside during Siberia’s brief transition from summer to winter. By the spring of 2003 she knew exactly what she needed to do: place her gas traps directly over known seeps. Her results have since riveted attention on how drastically thawing permafrost could speed up global warming.

Trapping the Demon
During four years of doctoral work, Walter spent 20 months in the Siberian wilderness, often alone or with only one loyal field assistant. She hiked up to eight miles a day across sodden tundra and braved icy waters on several occasions, deliberately as well as accidentally. She knew exactly what she was getting into; as a high school exchange student to Russia nine years earlier, Walter had learned the language and was deeply touched by the harsh conditions of post-Soviet life. She jumped at the chance to return.

Headquarters for much of those four years was the so-called Northeast Science Station, a small outpost in Cherskii, about 90 miles south of the Arctic Ocean. The station’s director, legendary ecologist Sergey Zimov, who had published his suspicions about the role of lake emissions in climate change, helped to define Walter’s straightforward goal: find a way to quantify the methane release and determine what fraction could be attributed to thawing permafrost. Walter’s first challenge was to invent a way to capture the gas. She knew she would eventually need hundreds of contraptions to adequately sample the two large lakes in her study, so her design needed to be simple—and cheap. Walter and her Siberian field assistant spent weeks cobbling together traps in the station’s cramped attic, mostly from recycled trash they found at abandoned Soviet military bases and along dusty dirt roads. For each trap, they secured an inverted plastic bottle to the center of an umbrella-shaped plastic skirt, which was held open by a hoop of wire to funnel bubbles upward. They made 75 of them in all.

During her first excursions, Walter dutifully placed the traps randomly across the lakes’ unfrozen surface, according to standard scientific protocol. “We put a lot of hard work in that, and I was frustrated,” Walter says. “We could see the bubbles, but we weren’t catching much gas.” It wasn’t until she walked out onto the freshly frozen ice for the first time and saw the disparate collections of bubbles that she realized the methane was rising up at discrete points. She made an executive decision, a bit nervously and without the consent of her thesis advisers, to set the traps directly over seeps when the lakes thawed the following spring. So, in 2003, she set about anchoring many of her traps right near the lake bottom—a job that called for a snorkel and wet suit. Locating a seep and setting the necessary tripod of weights and ropes for a single trap required two and a half hours submerged in lake water still gripped by winter chill.

That same spring Walter’s colleague at Fairbanks, Vladimir Romanovsky, whose computer simulations are some of those predicting a dramatic thaw this century, made an unrelated visit to Cherskii and observed Walter swimming in the icy lakes: “She’s a tough girl,” he says simply. By summer Walter found herself in the hospital with pneumonia. “But a couple of months later, and with a good dose of Russian antibiotics, I was back in the lakes,” she recalls. When winter came again, the drill changed from snorkeling to shoveling. For hours at a time Walter dug away at the snow atop the ice, clearing paths above the seeps and marking them with flags as she went. “The Siberians were laughing their heads off at how much money we were spending to come to Siberia to shovel snow off the frozen lakes,” she says. But no one was laughing when the world learned about her hard-won findings.

Proof for a Spike
Walter’s intimate relationship with a handful of Siberian lakes initially brought lake emissions into the limelight, but it was her analysis of their global importance, which she reported in two major scientific journals in 2007, that really turned heads. The potential for emissions to increase dramatically became clear through her work with paleoecologist Mary Edwards of the University of Southampton in England, who has studied the life histories of Arctic lakes. Together they showed that methane bubbling out of Arctic lakes could have been responsible for up to 87% of the spike in methane emissions that helped the planet warm from the most recent ice age. At that time, roughly 11,400 years ago, global methane concentrations rose 50% in less than 200 years.

Many scientists are keen to determine whether such a dramatic spike might happen again. A steady march of global warming, spread out over hundreds or thousands of years, could set off the gaseous Arctic time bomb slowly. But a quicker thaw could ignite a runaway outgassing of methane.

For about a decade it has been clear that the ongoing loss of sea ice is accelerating the Arctic’s rapid warming, says climate modeler David Lawrence of the National Center for Atmospheric Research in Boulder, Colo. When summer ice retreated to a record minimum in 2007 and again last year, the outlook seemed to worsen by the month. New estimates, published in April by the National Oceanic and Atmospheric Administration, predict nearly ice-free summers by 2037—three times sooner than earlier models indicated. The prospect of more open water has nations scrambling to stake oil and gas claims to the Arctic seabed [see “Arctic Landgrab,” by Jessa Gamble; Scientific American Earth 3.0, Vol. 19, No. 1, 2009], but the backlash for climate change could be severe. Dark seawater absorbs more of the sun’s heat than white ice does, thus warming the region’s air and thereby the soil, putting permafrost at risk. Lawrence’s newest global climate simulations predict that warming associated with spells of particularly rapid loss of sea ice could lead directly to faster permafrost thaw. During such episodes, which would last five or 10 years, autumn temperatures might increase by as much as 9 °F along Arctic shorelines, and the heat penetrating inland would more than triple the average warming rates previously assumed.

Rising inland temperatures are fueling another dramatic change “potentially as profound as the loss of sea ice,” says Matthew Sturm of the U.S. Army’s Cold Regions Research and Engineering Laboratory in Fort Wainwright, Alaska. Shrubs are taking over great swaths of the tundra. During the summer, shrubs absorb more sunlight than does the mossier, grassier vegetation they replace, warming the ground further. And in the winter they create snowdrifts that help the ground hold on to summer heat. Sturm’s extensive comparison of 6,000 aerial photographs taken across northern Alaska for oil exploration during the 1940s to present-day surveys of the same locations shows significant shrub expansion, now covering 77,000 square miles.

Double the Emissions
Some Arctic scientists are quick to point out that certain environmental changes could slow warming rather than speed it up, however. Sturm has also found areas where shrubs are not expanding and soils are colder. In other regions, the conversion of mossy tundra to thin forest, not shrubland, offsets some rise in greenhouse gases by storing more carbon in trees. Still, the consensus is that warming will dominate. “The question is whether this is a weak positive or a strong positive,” Lawrence says. “It may take a long time to get the numbers right.”

Even now, though, Lawrence is willing to offer a lower bound of methane release. It is easy, he says, to envision conditions that double methane emissions from the Arctic by the end of the 21st century simply by activating more microbes in those uppermost few feet of Arctic soil that thaw every summer, the so-called active layer. But more lakes formed because of thawing would send that estimate skyrocketing. Walter’s work suggested that the lakes near Cherskii expanded significantly between 1974 and 2000 and that as they did, they ate into the permafrost along their shorelines. She found that methane rises up most vigorously at these outer edges, which fueled her 2006 estimate that an expansion of thaw lakes increased methane emissions in the region by 58%.

Going back to Siberia as a professor in 2008 made her wonder if it was time to update that estimate. The banks of the lake where she lit her first methane bubble in 2002 had advanced greatly. “The dramatic changes to my study sites really made my eyebrows go up,” she says. “I couldn’t even recognize the lake margins. Some ponds appeared to have doubled or tripled in size.” If other lakes experienced similar growth they may have contributed to the global methane spike that began two years ago.

Walter still spends four months or more each year walking the lakes in dogged pursuit of answers. Her collaborators and study sites have expanded considerably. To date, she and her colleagues have visited 60 lakes in Siberia and Alaska, but that is still only the tip of the proverbial iceberg. With no hope of visiting every Arctic thaw lake in person, her team is now working on a technique to spot methane seeps from space. One new high-resolution German satellite, TerraSAR-X, is making it possible to identify distinct patches of bubbles on the surfaces of frozen lakes—and to keep track of which patches are growing.

One More Reason to Cut Back
Once a given helping of permafrost starts to thaw and a gas leak starts, not much can be done about it. Local villages could capture the bubbling methane gas and use it to replace diesel fuel (technologies already exist for capturing methane released from landfills). But that is a “very small fix,” Walter concedes. The only real solution is to slow the thaw itself.
Those of us living at lower latitudes can make the greatest difference. The model linking permafrost thaw to loss of sea ice predicts that both processes could be slowed considerably if humanity stabilizes CO₂ emissions soon, slowing the atmospheric warming that is generating the methane. “It’s not a runaway train,” Lawrence says. Not yet, anyway, Walter and others warn. Lawrence sounds optimistic when he says, “Perhaps we have to reduce emissions by 80% rather than 70% by 2050.” But such dramatic reductions won’t be easy. Since 2000 human activities have raised CO₂ concentrations much faster than expected.

Even if humanity finds the resolve to slow warming, too much thawing in the wrong place could tap submerged caverns of methane. Just below the permafrost layer in many locations lurk large pockets of pure gas that formed millions of years ago. Some of the pockets are run-of-the-mill natural gas reserves, but others are so-called methane hydrates, massive deposits of ice that contain large amounts of gas within their crystalline structure.

Some scientists suspect that permafrost acts as a cap that protects hydrates from melting, particularly in the shallow Arctic seafloor, where the hydrates are found only a few tens of feet deep. The more that sea or lake waters thaw the permafrost below, the more likely this cap is to blow suddenly, releasing jets of methane up through the water and into the atmosphere. A team that included two of Walter’s colleagues at Fairbanks found such plumes rising up from the shallow continental shelf of Siberia in 2008. Possibly, these releases have been happening for a long time, and we are only now noticing them. But the discoverers point out that the Siberian shelf alone holds an estimated 1.4 trillion tons of methane in the form of gas hydrates—equivalent to the newest estimates of the total greenhouse gases that would be released during a complete permafrost thaw.

Many researchers note that methane hydrates exist below the permafrost on land as well. The deposits are generally assumed to be too deep to be at risk of thawing. But that assumption, like others before it, has been cast in doubt. If Walter confirms indications from a field excursion earlier this year that Arctic lakes are tapping a methane source even older and greater than permafrost, her alerts would have to be cranked up considerably. And those bubbles she lights would take on an even more sinister glow.

More beasts, less burden: Large animals could help keep permafrost frozen.
Strangely enough, one way to slow the thawing of permafrost is to reintroduce massive herds of large, plant-eating animals to the Arctic landscape to mimic the days when millions of mammoths roamed the Siberian steppes. Although the idea may sound like science fiction, it is based in sound ecology. “Snow is like a down jacket that keeps the ground warm,” University of Alaska–Fairbanks researcher Katey Walter points out. “As the activity of animals compresses the snow or removes it through their foraging, the cold winter temperatures can penetrate deeper into the ground and keep the permafrost frozen.” Indeed, ecologist Sergey Zimov, director of the Northeast Science Station in Cherskii, Siberia, has hired local villagers to fashion that solution with their own hands. They have fenced off a 625-square-mile ranch Zimov calls Pleistocene Park and stocked it with moose, reindeer and Yakutian horses. Zimov has mimicked mammoths by driving around a military tank to crush the ground, too. He argues that the climate is still optimal for grassland, which would also insulate the permafrost below, if animals can thrive to cultivate it. Hunting, not climate, he points out, is blamed for the mammoth’s demise.

Note: This article was originally printed with the title, "The Peril below the Ice."

Link: http://www.scientificamerican.com/article.cfm?id=the-peril-below-the-ice

Modiki El Niño variant of El Niño linked to more frequent hurricanes

El Niño Variant Is Linked to Hurricanes in Atlantic

by Cornelia Dean, New York Times, July 2, 2009

Scientists have known for some time that El Niño, the warm spell that turns up every four or five years in the waters of the eastern Pacific Ocean, reduces hurricane activity in the Atlantic. But in a new study, researchers at the Georgia Institute of Technology have linked a variant of that pattern — periodic warming in the central Pacific — to more frequent hurricanes in the Atlantic, particularly on the Gulf Coast and in the Caribbean.

The researchers and scientists who have reviewed their work said it was too soon to say whether the warming pattern resulted from global climate change or simply had been undetected.

Scientists can detect warming in the central Pacific earlier than they can discern the development of El Niño, the researchers said, so the new finding may help improve forecasts for hurricane seasons over all.

In an El Niño year, warming of the eastern Pacific changes air flow patterns in the troposphere, the lowest portion of Earth’s atmosphere, so that one layer moves eastward and the other westward. Wind shear then develops over the Atlantic, inhibiting the ability of storms to turn into tight, powerful gyres.

But the warming patterns that occur in the central Pacific cause the wind shear phenomenon to shift well to the west, the researchers say, allowing Atlantic hurricanes to form relatively unimpeded.

Peter J. Webster, a professor of earth sciences at Georgia Tech and an author of the report, said the variant pattern was discovered in the 1980s by Japanese and Korean researchers, who dubbed it “modiki” El Niño. (Modiki is Japanese for “similar but different.”)

Dr. Webster said it might be difficult for researchers to determine whether the warming pattern was new because their observational record was relatively short and their climate models were imperfect.

Kerry Emanuel, a climate expert at the Massachusetts Institute of Technology, said the new work was impressive. But he added that he believed that the pattern “has been there all along, but we just didn’t see it.”

Link to article: http://www.nytimes.com/2009/07/03/science/earth/03hurricane.html

Thomas Friedman: Just Do It

Just Do It

by THOMAS L. FRIEDMAN, New York Times, June 30, 2009

There is much in the House cap-and-trade energy bill that just passed that I absolutely hate. It is too weak in key areas and way too complicated in others. A simple, straightforward carbon tax would have made much more sense than this Rube Goldberg contraption. It is pathetic that we couldn’t do better. It is appalling that so much had to be given away to polluters. It stinks. It’s a mess. I detest it.

Thomas L. Friedman. Fred R. Conrad/The New York Times

• Read All Comments (113) »

Now let’s get it passed in the Senate and make it law.

Why? Because, for all its flaws, this bill is the first comprehensive attempt by America to mitigate climate change by putting a price on carbon emissions. Rejecting this bill would have been read in the world as America voting against the reality and urgency of climate change and would have undermined clean energy initiatives everywhere.

More important, my gut tells me that if the U.S. government puts a price on carbon, even a weak one, it will usher in a new mind-set among consumers, investors, farmers, innovators and entrepreneurs that in time will make a big difference — much like the first warnings that cigarettes could cause cancer. The morning after that warning no one ever looked at smoking the same again.

Ditto if this bill passes. Henceforth, every investment decision made in America — about how homes are built, products manufactured or electricity generated — will look for the least-cost low-carbon option. And weaving carbon emissions into every business decision will drive innovation and deployment of clean technologies to a whole new level and make energy efficiency much more affordable. That ain’t beanbag.

Now that the bill is heading for the Senate, though, we must, ideally, try to improve it, but, at a minimum, guard against diluting it any further. To do that we need the help of the three parties most responsible for how weak the bill already is: the Republican Party, President Barack Obama and We the People.

This bill is not weak because its framers, Representatives Henry Waxman and Ed Markey, wanted it this way. “They had to make the compromises they did,” said Dan Becker, director of the Safe Climate Campaign, “because almost every House Republican voted against the bill and did nothing to try to improve it. So to get it passed, they needed every coal-state Democrat, and that meant they had to water it down to bring them on board.”

What are Republicans thinking? It is not as if they put forward a different strategy, like a carbon tax. Does the G.O.P. want to be the party of sex scandals and polluters or does it want to be a partner in helping America dominate the next great global industry: E.T. — energy technology? How could Republicans become so anti-environment, just when the country is going green?

Historically speaking, “Republicans can claim as much credit for America’s environmental leadership as Democrats,” noted Glenn Prickett, senior vice president at Conservation International. “The two greatest environmental presidents in American history were Teddy Roosevelt, who created our national park system, and Richard Nixon, whose administration gave us the Clean Air Act and the Environmental Protection Agency.” George Bush Sr. signed the 1993 Rio Treaty, to preserve biodiversity.

Yes, this bill’s goal of reducing U.S. carbon emissions to 17 percent below 2005 levels by 2020 is nowhere near what science tells us we need to mitigate climate change. But it also contains significant provisions to prevent new buildings from becoming energy hogs, to make our appliances the most energy efficient in the world and to help preserve forests in places like the Amazon.

We need Republicans who believe in fiscal conservatism and conservation joining this legislation in the Senate. We want a bill that transforms the whole country not one that just threads a political needle. I hope they start listening to green Republicans like Dick Lugar, George Shultz and Arnold Schwarzenegger.

I also hope we will hear more from President Obama. Something feels very calculating in how he has approached this bill, as if he doesn’t quite want to get his hands dirty, as if he is ready to twist arms in private, but not so much that if the bill goes down he will get tarnished. That is no way to fight this war. He is going to have to mobilize the whole country to pressure the Senate — by educating Americans, with speech after speech, about the opportunities and necessities of a serious climate/energy bill. If he is not ready to risk failure by going all out, failure will be the most likely result.

And then there is We the People. Attention all young Americans: your climate future is being decided right now in the cloakrooms of the Capitol, where the coal lobby holds huge sway. You want to make a difference? Then get out of Facebook and into somebody’s face. Get a million people on the Washington Mall calling for a price on carbon. That will get the Senate’s attention. Play hardball or don’t play at all.

Link: http://www.nytimes.com/2009/07/01/opinion/01friedman.html

With a melting Greenland as a backdrop, Danish minister urges climate action

Posted 10:59 PM on 30 Jun 2009
by Geoffrey Lean

. The Sermeq Kujalleq glacier (also known as the Jakobshavn Glacier) near where it flows into the sea in western Greeland. The photo was taken in the summer of 2008. Scientists have recorded the glacier’s rapid melt over the past decade. Courtesy kriskaer via Flickr

Here’s a tip for the ministers who are attending the latest of the long series of meetings preparing for the make-or-break climate negotiations in Copenhagen this December.

Go visit the valley of the dogs.

Yes, that’s dogs, not dolls. Greenland sled dogs to be precise. For this week’s meeting of 30 ministers from key countries is in Ilulissat, the third biggest settlement on the immense, increasingly melting island.

They have been invited there for informal “substantive and open” discussions, far from the media, by Connie Hedegaard the impressive Danish Minister for Climate and Energy. She has been holding such ministerial dialogues in different parts of the world for the past five years, but Ilulissat is her prime location, her secret weapon.

A former journalist, she well understands that “seeing is believing.” And in this small coastal town overlooking a sea strewn with icebergs, the evidence of global warming is both unmistakable and overwhelming. She has hosted a whole series of key figures there over the last years, including House Speaker Nancy Pelosi, Sen. John McCain, and German Chancellor Angela Merkel. She wants President Obama to come too.

. With her country hosting the next major international talks on climate change, Denmark’s Connie Hedegaard has been bringing world leaders to Greenland in hopes that seeing global warming’s effects up close will spur them to action.Courtesy Denmark’s Ministry for Climate and EnergyI was there almost two years ago with Bartholomew I, the Ecumenical Patriarch of the Eastern Orthodox Church. Dubbed “the green pope” for his deep environmental concern, he has held a series of shipboard seminars on religion, science and the environment, on seas and rivers around the world, and this one started just off Ilulissat, home to 4,500 people and 2,500 sled dogs.

Ah yes, those dogs. I came across them on a trip ashore, when the whole shipload of us took a walk from the town to an ancient settlement on a nearby shore. In a valley, stretching as far as the eye could see, were countless scratching, sleeping, howling animals, tethered next to makeshift kennels. It must be the strangest settlement of the unemployed on the face of the warming Earth.

Until recently the dogs were busy and treasured, vital engines of transport in a land without roads, where the easiest routes from place to place—or to the best hunting spots—are often across the frozen ocean. But for five years before I was there the sea had failed to freeze, giving the hunters and their dogs nowhere to go.

It is much the same story hundreds of miles away at Qaanaak in the island’s far northwest. The sea still freezes there, but the ice comes one and a half months later than a few years ago, and melts one and a half months earlier. For the local Inuit, who subsist by hunting over the ice with their sleds, it is—as explained to me—“like your boss taking away three months for your pay without giving you notice.”

You can hear the howling of the idle dogs, reputedly descended from wolves, all over Ilulissat. But even this is not the most remarkable, or portentous, sound that fills the air. That sound—loud booms that sometimes rumble like approaching thunder or other times crack sharply like a gunshot—accompanies the calving of yet another iceberg from the giant Sermeq Kujalleq [see map at bottom of next page] glacier reaching the sea just beyond the canine valley.

The booms are ever more frequent these days, for the glacier is melting ever faster as Greenland warms up three times as fast as the rest of the world. Every day it now sheds enough fresh water, in the form of ice, to supply the whole of London or New York for an entire year.

The glacier, the biggest in Greenland, is racing towards the sea at a rate of nearly ten miles a year, five times as fast as a decade ago. And it can go even faster—at one point scientists were shocked to find that part of it had surged three miles in just 90 minutes.

You can see the start of the process if you fly over the glacier. Melt water on the surface is finding its way down to the rock beneath, not in gentle trickles but in giant waterfalls that have carved great caverns in the ice; some are said to be as large as the Niagara Falls.

This has created a lake 500 meters deep under the glacier, lifting the ice and lubricating the glacier’s passage. And much the same is happening all around Greenland, causing its ice-cap to melt far faster than anyone had expected, contributing to the inevitable rising of the world’s seas.

I defy any rational person to see all this and not be struck with the urgency of combatting global warming. The ministers at this week’s climate meeting will surely be shown the glacier; they have been promised “excursions to ... view first hand the consequences of climate change.”

Rational people that they are, let’s hope they get the point and act accordingly ... and fast.

Below: Video of the Ilulissat Icefjord from www.100places.com.

Link to article: http://www.grist.org/article/index/2009-06-30-greenland-hedegaard-climate/PALL/

ExxonMobil continuing to fund climate sceptic groups, records show

Dear Readers,

Excuse me, but was anyone actually so naive as to believe that ExxonMobil had actually stopped funding denialist junk science pronouncements intended to manipulate public opinion? Just let me know, I have a bridge to sell.

ExxonMobil continuing to fund climate sceptic groups, records show

Records show ExxonMobil gave hundreds of thousands of pounds to lobby groups that have published 'misleading and inaccurate information' about climate change

• David Adam, environment corresponden, guardian.co.uk, Wednesday 1 July 2009
  

The world's largest oil company is continuing to fund lobby groups that question the reality of global warming, despite a public pledge to cut support for such climate change denial, a new analysis shows.

Company records show that ExxonMobil handed over hundreds of thousands of pounds to such lobby groups in 2008. These include the National Center for Policy Analysis (NCPA) in Dallas, Texas, which received $75,000 (£45,500), and the Heritage Foundation in Washington DC, which received $50,000.

According to Bob Ward, policy and communications director at the Grantham Research Institute on Climate Change and the Environment, at the London School of Economics, both the NCPA and the Heritage Foundation have published "misleading and inaccurate information about climate change."

On its website, the NCPA says: "NCPA scholars believe that while the causes and consequences of the earth's current warming trend is [sic] still unknown, the cost of actions to substantially reduce CO2 emissions would be quite high and result in economic decline, accelerated environmental destruction, and do little or nothing to prevent global warming regardless of its cause."

The Heritage Foundation published a "web memo" in December that said: "Growing scientific evidence casts doubt on whether global warming constitutes a threat, including the fact that 2008 is about to go into the books as a cooler year than 2007". Scientists, including those at the UK Met Office say that the apparent cooling is down to natural changes and does not alter the long-term warming trend.

In its 2008 corporate citizenship report, published last year, ExxonMobil said it would cut funds to several groups that "divert attention" from the need to find new sources of clean energy.

The NCPA and Heritage Foundation are included among groups funded by ExxonMobil, according to details of its "2008 Worldwide Contributions and Community Investments" published recently.

Ward said: "ExxonMobil has been briefing journalists for three years that they were going to stop funding these groups. The reality is that they are still doing it. If the world's largest oil company wants to fund climate change denial then it should be upfront about it, and not tell people it has stopped."

In 2006, Ward, then at the Royal Society, wrote to ExxonMobil to challenge the company's funding of such lobby groups. The move, revealed in the Guardian, prompted accusations of censorship and debate about whether experts should "police" the distribution of scientific information.

In an article on the Guardian website, Ward writes: "I have now written again to ExxonMobil to point out that these organisations publish misleading information about climate change on their websites, and to seek guidance on how to reconcile this fact with the pledge made by the company. I believe that the company should keep its promise by ending its financial support for lobby groups that mislead the public about climate change."

ExxonMobil said it annually reviews and adjusts its contributions to policy research groups. A spokesman said: "Only ExxonMobil speaks for ExxonMobil, and our position on climate change is clear. We have the same concerns as people everywhere, and that is how to provide the world with the energy it needs while reducing greenhouse gas emissions. We take the issue of climate change seriously and the risks warrant action."

Link to article: http://www.guardian.co.uk/environment/2009/jul/01/exxon-mobil-climate-change-sceptics-funding