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"Estimates of Earth's climate sensitivity are uncertain, largely because of uncertainty in the long-term cloud feedback. I estimated the magnitude of the cloud feedback in response to short-term climate variations by analyzing the top-of-atmosphere radiation budget from March 2000 to February 2010. Over this period, the short-term cloud feedback had a magnitude of 0.54 ± 0.74 (2σ) watts per square meter per kelvin, meaning that it is likely positive. A small negative feedback is possible, but one large enough to cancel the climate's positive feedbacks is not supported by these observations. Both long- and short-wave components of short-term cloud feedback are also likely positive. Calculations of short-term cloud feedback in climate models yield a similar feedback. I find no correlation in the models between the short- and long-term cloud feedbacks. "

"Recognising ocean acidification in deep time: An evaluation of the evidence for acidification across the Triassic-Jurassic boundary Sarah E. GreeneCorresponding author contact information, 1, E-mail the corresponding author, Rowan C. Martindale1, E-mail the corresponding author, Kathleen A. Ritterbush E-mail the corresponding author, David J. Bottjer E-mail the corresponding author, Frank A. Corsetti E-mail the corresponding author, William M. Berelson E-mail the corresponding author Department of Earth Sciences, University of Southern California, Los Angeles, California, USA 90089 Received 22 July 2011. Accepted 17 March 2012. Available online 5 April 2012. While demonstrating ocean acidification in the modern is relatively straightforward (measure increase in atmospheric CO2 and corresponding ocean chemistry change), identifying palaeo-ocean acidification is problematic. The crux of this problem is that the rock record is a constructive archive while ocean acidification is essentially a destructive (and/or inhibitory) phenomenon. This is exacerbated in deep time without the benefit of a deep ocean record. Here, we discuss the feasibility of, and potential criteria for, identifying an acidification event in deep time. Furthermore, we investigate the evidence for ocean acidification during the Triassic-Jurassic (T-J) boundary interval, an excellent test case because 1) it occurs in deep time, beyond the reach of deep sea drilling coverage; 2) a potential trigger for acidification is known; and 3) it is associated with one of the 'Big Five' mass extinctions which disproportionately affected modern-style invertebrates. Three main criteria suggest that acidification may have occurred across the T-J transition. 1) The eruption of the Central Atlantic Magmatic Province (CAMP) and the associated massive and rapid release of CO2 coincident with the end-Triassic mass extinction provide a suitable trigger for an acidification event (

"Science 25 November 2011: Vol. 334 no. 6059 pp. 1052-1053 DOI: 10.1126/science.334.6059.1052 * News Focus Adaptation to Climate Change Adaptation to Climate Change Time to Adapt to a Warming World, But Where's the Science? 1. Richard A. Kerr With dangerous global warming seemingly inevitable, users of climate information-from water utilities to international aid workers-are turning to climate scientists for guidance. But usable knowledge is in short supply. Figure View larger version: * In this page * In a new window Adapt to that. Climate will change, but decision-makers want to know how, where, and when. "CREDIT: KOOS VAN DER LENDE/NEWSCOM" DENVER, COLORADO-The people who brought us the bad news about climate change are making an effort to help us figure out what to do about it. As climate scientists have shown, continuing to spew greenhouse gases into the atmosphere will surely bring sweeping changes to the world-changes that humans will find it difficult or impossible to adapt to. But beyond general warnings, there is another sort of vital climate research to be done, speakers told 1800 attendees at a meeting here last month. And so far, they warned, researchers have delivered precious little of the essential new science. At the meeting, subtitled "Climate Research in Service to Society,"* the new buzzword was "actionable": actionable science, actionable information, actionable knowledge. "There's an urgent need for actionable climate information based on sound science," said Ghassem Asrar, director of the World Climate Research Programme, the meeting's organizer based in Geneva, Switzerland. What's needed is not simply data but processed information that an engineer sizing a storm-water pipe to serve for the next 50 years or a farmer in Uganda considering irrigating his fields can use to make better decisions in a warming world. Researchers preparing for the next international climate assessment, due in 2013, delive

"Science 25 November 2011: Vol. 334 no. 6059 p. 1040 DOI: 10.1126/science.334.6059.1040 * News & Analysis Climate Change Humans Are Driving Extreme Weather; Time to Prepare 1. Richard A. Kerr Figure View larger version: * In this page * In a new window Thai floods 2011 Hurricane Katrina 2005 Texas drought 2011 "CREDITS (LEFT TO RIGHT): PAULA BRONSTEIN/GETTY IMAGES; JEFF SCHMALTZ, MODIS RAPID RESPONSE TEAM, NASA/GSFC; NOAA" An international scientific assessment finds for the first time that human activity has indeed driven not just global warming but also increases in some extreme weather and climate events around the world in recent decades. And those and likely other weather extremes will worsen in coming decades as greenhouse gases mount, the report finds. But uncertainties are rife in the still-emerging field of extreme events. Scientists cannot attribute a particular drought or flood to global warming, and they can say little about past or future trends in the risk of high-profile hazards such as tropical cyclones. Damage from weather disasters has been climbing, but the report can attribute that trend only to the increasing exposure of life and property to weather risks. Climate change may be involved, but a case cannot yet be made. Despite the uncertainties, the special report from the Intergovernmental Panel on Climate Change (IPCC) released 18 November stresses that there is still reason for taking action now. The panel recommends "low-regrets measures," such as improvements in everything from drainage systems to early warning systems. Such measures would benefit society in dealing with the current climate as well as with almost any range of possible future climates. The report takes a cautious, consensus-based approach that draws on the published literature. Headlines and even some scientists may point to the current Texas drought or the 2003 European heat wave as the result of the strengthening greenhouse. But the report fin

A major puzzle of paleoclimatology is why, after a long interval of cooling climate, each late Quaternary ice age ended with a relatively short warming leg called a termination. We here offer a comprehensive hypothesis of how Earth emerged from the last global ice age. A prerequisite was the growth of very large Northern Hemisphere ice sheets, whose subsequent collapse created stadial conditions that disrupted global patterns of ocean and atmospheric circulation. The Southern Hemisphere westerlies shifted poleward during each northern stadial, producing pulses of ocean upwelling and warming that together accounted for much of the termination in the Southern Ocean and Antarctica. Rising atmospheric CO2 during southern upwelling pulses augmented warming during the last termination in both polar hemispheres.

Information Science Bounds and Vision Atlas of Science Visualizing What We Know by Katy Börner MIT Press, Cambridge, MA, 2010. 266 pp. $$29.95, £22.95. ISBN 9780262014458. 1. Mason A. Porter + Author Affiliations 1. The reviewer is at the Oxford Centre for Industrial and Applied Mathematics, Mathematical Institute, University of Oxford, Oxford OX1 3LB, UK, and at the CABDyN Complexity Centre and Somerville College, University of Oxford. 1. E-mail: porterm@maths.ox.ac.uk Visualization is a crucial but underappreciated part of science. As venues like the American Physical Society's Gallery of Fluid Motion and Gallery of Nonlinear Images illustrate every year, good visuals can make science more beautiful, more artistic, more tangible, and often more discernible. Katy Börner's continuing exhibition Places & Spaces: Mapping Science (1) and her book Atlas of Science: Visualizing What We Know arise from a similar spirit but are much more ambitious. Visualization is one of the most compelling aspects of science. Breathtaking visuals from sources like fractals and Disneyland's long-dead "Adventure Thru Inner Space" ride are what originally inspired me toward my personal scientific path, so I welcome any resource that promises to bring the visual joys of discovery to a wide audience. Importantly, Börner's exhibition and book are not mere artistic manifestations, although they would be impressive accomplishments even if that were her only goal. Some scientists have occasionally had great success in the visual arts; for example, physicist Eric Heller has long exhibited the gorgeous fruits of his research on quantum chaos and other topics (2). To fully appreciate Börner's efforts, however, one must be conscious that she is deeply concerned not just with visualization itself but with the science of visualization. Accordingly, her book discusses the history of the science of visualization, where it is now, and where she thinks it can go. Atlas of Scie

The bad news just got worse: A new study finds that reining in greenhouse gas emissions in time to avert serious changes to Earth's climate will be at best extremely difficult. Current goals for reducing emissions fall far short of what would be needed to keep warming below dangerous levels, the study suggests. To succeed, we would most likely have to reverse the rise in emissions immediately and follow through with steep reductions through the century. Starting later would be far more expensive and require unproven technology.

Experts Agree Global Warming Is Melting the World Rapidly Richard A. Kerr Forty-seven glaciologists have arrived at a community consensus over all the data on what the past century's warming has done to the great ice sheets: a current annual loss of 344 billion tons of glacial ice, accounting for 20% of current sea level rise. Greenland's share-about 263 billion tons-is roughly what most researchers expected, but Antarctica's represents the first agreement on a rate that had ranged from a far larger loss to an actual gain. The new analysis, published on page 1183 of this week's issue of Science, also makes it clear that losses from Greenland and West Antarctica have been accelerating, showing that some ice sheets are disconcertingly sensitive to warming.

Keeping Coral Clean Seaweed overgrowth is a major problem for coral reefs and also seems to be a consequence of excessive harvesting of herbivorous fish. Dixson and Hay (p. 804) examined this effect on Fijian reefs. Species of small herbivorous gobies and coral-associated damselfish were compared for their effect on the toxic Chlorodesmis seaweed in experiments that required caging colonies of the branching coral Acropora nasuta and the associated fish species. Only the gobies actively removed algal fronds attached to the cages and only one species (itself toxic to predators) ate them; the damselfish simply defected from the arena when toxic algae were present. The hydrophobic toxins exuded in the algal mucus lysed coral polyps releasing cell constituents that, together with the algal toxin, attract the gobies, which then eat the algal fronds. Interestingly, the toxic goby became more toxic to predators after consumption of the seaweed, which may help to drive symbiosis with a coral colony.

Warming and Melting Mass loss from the ice sheets of Greenland and Antarctica account for a large fraction of global sea-level rise. Part of this loss is because of the effects of warmer air temperatures, and another because of the rising ocean temperatures to which they are being exposed. Joughin et al. (p. 1172) review how ocean-ice interactions are impacting ice sheets and discuss the possible ways that exposure of floating ice shelves and grounded ice margins are subject to the influences of warming ocean currents. Estimates of the mass balance of the ice sheets of Greenland and Antarctica have differed greatly-in some cases, not even agreeing about whether there is a net loss or a net gain-making it more difficult to project accurately future sea-level change. Shepherd et al. (p. 1183) combined data sets produced by satellite altimetry, interferometry, and gravimetry to construct a more robust ice-sheet mass balance for the period between 1992 and 2011. All major regions of the two ice sheets appear to be losing mass, except for East Antarctica. All told, mass loss from the polar ice sheets is contributing about 0.6 millimeters per year (roughly 20% of the total) to the current rate of global sea-level rise.

Winds of Change Jane Qiu Antarctica does not respond to global warming uniformly like a giant ice cube. Changing wind patterns are an unsung force shaping Antarctica's future. Retreating sea ice and stronger winds have caused seawater to mix more deeply, a process that churns sunlight-dependent phytoplankton into the ocean's depths. As a result, phytoplankton biomass has declined by 12% over the past 30 years. Higher on the food chain, that means fewer krill and fish larvae. These creatures are also getting hammered by the loss of sea ice, which hides them from predators. The complex interplay between air, sea, and ice has emerged as a central theme underlying climate change in Antarctica. Shifting wind patterns and corresponding ocean changes can explain climate responses across the continent.

"Slowing climate change requires overcoming inertia in political, technological, and geophysical systems. Of these, only geophysical warming commitment has been quantified. We estimated the commitment to future emissions and warming represented by existing carbon dioxide-emitting devices. We calculated cumulative future emissions of 496 (282 to 701 in lower- and upper-bounding scenarios) gigatonnes of CO2 from combustion of fossil fuels by existing infrastructure between 2010 and 2060, forcing mean warming of 1.3°C (1.1° to 1.4°C) above the pre-industrial era and atmospheric concentrations of CO2 less than 430 parts per million. Because these conditions would likely avoid many key impacts of climate change, we conclude that sources of the most threatening emissions have yet to be built. However, CO2-emitting infrastructure will expand unless extraordinary efforts are undertaken to develop alternatives. "

The shallow water reefs of the Coral Triangle, which stretches across Indonesia and north through the Philippines, host the world's greatest diversity of corals, fish, crustaceans, mollusks, and marine plant species. Now preliminary results from a joint Indonesian-U.S. marine survey indicate that the biodiversity runs deep. A remotely operated vehicle has captured stunning images of massive corals, as well as unusual crustaceans and fish living at depths never before surveyed, thousands of meters below the surface. And mapping of that sea floor has turned up a huge, previously unknown volcano.