Dry regions becoming drier: Ocean salinities show an intensified. The stronger water cycle means arid regions have become drier and high rainfall regions wetter as atmospheric temperature increases. The study, co-authored by CSIRO scientists Paul Durack and Dr Susan Wijffels, shows the surface ocean beneath rainfall-dominated regions has freshened, whereas ocean regions dominated by evaporation are saltier. The paper also confirms that surface warming of the world's oceans over the past 50 years has penetrated into the oceans' interior changing deep-ocean salinity patterns.
"This is further confirmation from the global ocean that the Earth's water cycle has accelerated," says Mr Durack -- a PhD student at the joint CSIRO/University of Tasmania, Quantitative Marine Science program. "These broad-scale patterns of change are qualitatively consistent with simulations reported by the Intergovernmental Panel on Climate Change (IPCC). The ocean's average surface temperature has risen around 0.4ºC since 1950.
Global warming monitoring needs to find 'missing heat', say scie. Sea surface temperature from March this year. Illustration: MODIS/Aqua/NASA Experts need to beef up ways to measure the heat content of oceans as a way to track more reliably the course of global warming, scientists say today. Kevin Trenberth and John Fasullo, climate scientists at the National Centre for Atmospheric Research in Boulder, Colorado, say that only about half of the heat believed to have built up in the Earth in recent years can be accounted for. New instruments are needed to locate and monitor this missing heat, they say, which could be storing up trouble for the future. "The heat will come back to haunt us sooner or later," Trenberth said. Although the rise in surface temperature in recent decades is the most well-known consequence of the thickening blanket of greenhouse gases around the Earth, it represents just a tiny fraction of the extra heat trapped.
Fasullo said: "Global warming at its heart is driven by an imbalance of energy. Deadly Heat Waves Are Becoming More Frequent In California. From mid July to early August 2006, a heat wave swept through the southwestern United States. Temperature records were broken at many locations and unusually high humidity levels for this typically arid region led to the deaths of more than 600 people, 25,000 cattle and 70,000 poultry in California alone. An analysis of this extreme episode carried out by researchers at Scripps Institution of Oceanography, UC San Diego, put this heat wave in the context of six decades of observed heat waves. Their results suggest that such regional extremes are becoming more and more likely as climate change trends continue.
The team, led by climate scientist Alexander Gershunov, examined meteorological conditions that lead to this and other recorded heat waves, when temperatures rose into the hottest one percent of historical summertime daily and nightly temperatures recorded in California and Nevada since 1948. "Water vapor is the main greenhouse gas. Arctic passage open without ice breakers first time in history. This year's opening marks the fourth time in five years that the Northeast Passage has opened, and commercial shipping companies are taking note.
Two German ships recently are the first commercial voyage ever made through the Northeast Passage without the help of icebreakers. The Northeast Passage trims 4,500 miles off the 12,500-mile trip through the Suez Canal, yielding considerable savings in fuel. The voyage was not possible last year, because Russia had not yet worked out a permitting process. With Arctic sea ice expected to continue to decline in the coming decades, shipping traffic through the Northeast Passage will likely become commonplace most summers. The past decade was the warmest decade in the Arctic for the past 2,000 years, according to a study called "Recent Warming Reverses Long-Term Arctic Cooling" published in the journal Science. This cooling should have continued through the 20th and 21st centuries and beyond as the 21,000-year cycle played out. Mysterious Glaciers That Grew When Asia Heated Up. Ice, when heated, is supposed to melt. That’s why a collection of glaciers in the Southeast Himalayas stymies those who know what they did 9,000 years ago.
While most other Central Asian glaciers retreated under hotter summer temperatures, this group of glaciers advanced from one to six kilometers. A new study by BYU geologist Summer Rupper pieces together the chain of events surrounding the unexpected glacial growth. “Stronger monsoons were thought to be responsible,” said Rupper, who reports her findings in the September issue of the journal Quaternary Research. As Central Asia’s summer climate warmed as much as 6 degrees Celsius, shifting weather patterns brought more clouds to the Southeast Himalayas. Temperatures also dropped when higher winds spurred more evaporation in this typically humid area, the same process behind household swamp coolers. Gerard Roe and Alan Gillespie of the University of Washington are co-authors of the new study.
Raw Video: Locust Swarms Invade South Australia. This is just the beginning, warn scientists - Times Online. Climate Modeling With Supercomputers. Global warming: Future temperatures could exceed livable limits, Reasonable worst-case scenarios for global warming could lead to deadly temperatures for humans in coming centuries, according to research findings from Purdue University and the University of New South Wales, Australia. Researchers for the first time have calculated the highest tolerable "wet-bulb" temperature and found that this temperature could be exceeded for the first time in human history in future climate scenarios if greenhouse gas emissions continue at their current rate. Wet-bulb temperature is equivalent to what is felt when wet skin is exposed to moving air.
It includes temperature and atmospheric humidity and is measured by covering a standard thermometer bulb with a wetted cloth and fully ventilating it. "Although areas of the world regularly see temperatures above 100 degrees, really high wet-bulb temperatures are rare," Huber said. The study did not provide new evaluations of the likelihood of future climate scenarios, but explored the impacts of warming. Sensitive side. (PhysOrg.com) -- A little extra carbon dioxide in the air may, unfortunately, go further towards warming Earth than previously thought.
A team of British and U.S. researchers have uncovered evidence [1] that Earth’s climate may be up to 50 percent more sensitive to long-term increases in atmospheric carbon dioxide than current climate models predict. The reason for the underestimation, they say, may be due to long-term changes in ice sheets and vegetation that are not well represented in today’s global climate models.
Just how much will global temperature rise in response to increases in atmospheric carbon dioxide? This is one of the key questions that climate scientists need to answer. But according to a recent study by a team of researchers that includes Gavin Schmidt of NASA’s Goddard Institute for Space Studies, Earth’s climate is also influenced by other, much slower processes.
More information: [1] Daniel J. Global warming likely to be amplified by slow changes to Earth s. Researchers studying a period of high carbon dioxide levels and warm climate several million years ago have concluded that slow changes such as melting ice sheets amplified the initial warming caused by greenhouse gases. The study, published in the journal Nature Geoscience, found that a relatively small rise in atmospheric carbon dioxide levels was associated with substantial global warming about 4.5 million years ago during the early Pliocene. Coauthor Christina Ravelo, professor of ocean sciences at the University of California, Santa Cruz, said the study indicates that the sensitivity of Earth's temperature to increases in carbon dioxide in the atmosphere is greater than has been expected on the basis of climate models that only include rapid responses. Carbon dioxide and other greenhouse gases trap heat in the atmosphere, leading to increased atmospheric and sea-surface temperatures.
Relatively rapid feedbacks include changes in atmospheric water vapor, clouds, and sea ice. Ice core studies confirm accuracy of climate models. An analysis has been completed of the global carbon cycle and climate for a 70,000 year period in the most recent Ice Age, showing a remarkable correlation between carbon dioxide levels and surprisingly abrupt changes in climate. The findings, to be published this week in the online edition of the journal Science, shed further light on the fluctuations in greenhouse gases and climate in Earth's past, and appear to confirm the validity of the types of computer models that are used to project a warmer climate in the future, researchers said. "We've identified a consistent and coherent pattern of carbon dioxide fluctuations from the past and are able to observe the correlation of this to temperature in the northern and southern hemispheres," said Ed Brook, an associate professor of geosciences at Oregon State University.
"This is a global, interconnected system of ocean and atmosphere, and data like these help us better understand how it works. " Source: Oregon State University. CO2 effects on plants increases global warming. Trees and other plants help keep the planet cool, but rising levels of carbon dioxide in the atmosphere are turning down this global air conditioner. According to a new study by researchers at the Carnegie Institution for Science, in some regions more than a quarter of the warming from increased carbon dioxide is due to its direct impact on vegetation. This warming is in addition to carbon dioxide's better-known effect as a heat-trapping greenhouse gas. For scientists trying to predict global climate change in the coming century, the study underscores the importance of including plants in their climate models. "Plants have a very complex and diverse influence on the climate system," says study co-author Ken Caldeira of Carnegie's Department of Global Ecology.
"Plants take carbon dioxide out of the atmosphere, but they also have other effects, such as changing the amount of evaporation from the land surface. First-ever 'State of the Carbon Cycle Report' finds troubling im. The first “State of the Carbon Cycle Report” for North America, released online this week by the U.S. Climate Change Science Program, finds the continent’s carbon budget increasingly overwhelmed by human-caused emissions.
North American sources release nearly 2 billion tons of carbon into the atmosphere each year, mostly as carbon dioxide. Carbon “sinks” such as growing forests may remove up to half this amount, but these current sinks may turn into new sources as climate changes. “By burning fossil fuel and clearing forests human beings have significantly altered the global carbon cycle,” says Chris Field of the Carnegie Institution’s Department of Global Ecology, one of the report’s lead authors. “In effect, we have been getting a huge subsidy from these unmanaged parts of the carbon cycle,” notes Field. But these carbon sinks may be reaching their limit as forests mature and climate conditions change. Source: Carnegie Institution. Stream water study detects thawing permafrost. Among the worrisome environmental effects of global warming is the thawing of Arctic permafrost -- soil that normally remains at or below the freezing point for at least a two-year period and often much longer.
Monitoring changes in permafrost is difficult with current methods, but a study by University of Michigan researchers offers a new approach to assessing the extent of the problem. The new study approach, which relies on chemical tracers in stream water, is described in the journal Chemical Geology. Overlying permafrost is a thin "active layer" that thaws every summer, and increases in the thickness of this layer over the years indicate thawing of permafrost. Both physical measurements and modeling suggest that active layer thickness has increased in some areas over the 20th century and that if present warming trends continue, increases of up to 40 percent could occur by the end of the 21st century. Kling, who is the Robert G. Bad sign for global warming: Thawing permafrost holds vast carbo.
Permafrost blanketing the northern hemisphere contains more than twice the amount of carbon in the atmosphere, making it a potentially mammoth contributor to global climate change depending on how quickly it thaws. So concludes a group of nearly two dozen scientists in a paper appearing this week in the journal Bioscience. The lead author is Ted Schuur, an associate professor of ecology at the University of Florida. Previous studies by Schuur and his colleagues elsewhere have estimated the carbon contained in permafrost in northeast Siberia. The new research expands that estimate to the rest of the permafrost-covered northern latitudes of Russia, Europe, Greenland and North America. The estimated 1,672 billion metric tons of carbon locked up in the permafrost is more than double the 780 billion tons in the atmosphere today. "It's bigger than we thought," Schuur said. Permafrost is frozen ground that contains roots and other soil organic matter that decompose extremely slowly.
Global warming could accelerate from thawing Siberian permafrost. Permafrost soil blanketing northeastern Siberia contains about 75 times more carbon than is released by burning fossil fuels each year. That means it could become a potent, likely unstoppable contributor to global climate change if it continues to thaw.
So conclude three scientists in a paper set to appear Friday in the journal Science. “Unfortunately, it’s another large pool of carbon on the list that could move into the atmosphere with continued warming,” said co-author Ted Schuur, an assistant professor of ecology in the University of Florida botany department. “You start thawing the permafrost, microbes release carbon dioxide, that makes things warmer, more permafrost thaws and the process continues.” The permafrost soil, which covers nearly 400,000 square miles of northeast Siberia and averages 82 feet in depth, contains about 500 billion metric tons of carbon, the scientists concluded.
Scientists have long known that permafrost, short for permanently frozen earth, contains carbon. Arctic land and seas account for up to 25 percent of world's car. In a new study in the journal Ecological Monographs, ecologists estimate that Arctic lands and oceans are responsible for up to 25 percent of the global net sink of atmospheric carbon dioxide. Under current predictions of global warming, this Arctic sink could be diminished or reversed, potentially accelerating predicted rates of climate change. In their review paper, David McGuire of the U.S. Geological Survey and the University of Alaska at Fairbanks and his colleagues show that the Arctic has been a carbon sink since the end of the last Ice Age, which over time has accounted for between zero and 25 percent, or up to about 800 million metric tons, of the global carbon sink. On average, says McGuire, the Arctic accounts for 10-15 percent of the Earth's carbon sink.
Carbon generally enters the oceans and land masses of the Arctic from the atmosphere and largely accumulates in permafrost, the frozen layer of soil underneath the land's surface. Source: Ecological Society of America. Thawing permafrost likely to boost global warming. Researchers find future temperatures could exceed livable limits.