Tuesday, February 27, 2007
Five Governors Agree to Work on Climate Change
Tuesday, December 12, 2006
UN downgrades man's impact on the climate
UN downgrades man's impact on the climate
Richard Gray, Science Correspondent, Sunday Telegraph
Mankind has had less effect on global warming than previously supposed, a United Nations report on climate change will claim next year. The UN Intergovernmental Panel on Climate Change says there can be little doubt that humans are responsible for warming the planet, but the organisation has reduced its overall estimate of this effect by 25 per cent. In a final draft of its fourth assessment report, to be published in February, the panel reports that the level of carbon dioxide in the atmosphere has accelerated in the past five years. It also predicts that temperatures will rise by up to 4.5 C during the next 100 years, bringing more frequent heat waves and storms. The panel, however, has lowered predictions of how much sea levels will rise in comparison with its last report in 2001. Climate change sceptics are expected to seize on the revised figures as evidence that action to combat global warming is less urgent. Scientists insist that the lower estimates for sea levels and the human impact on global warming are simply a refinement due to better data on how climate works rather than a reduction in the risk posed by global warming. One leading UK climate scientist, who asked not to be named due to the sensitivity surrounding the report before it is published, said: "The bottom line is that the climate is still warming while our greenhouse gas emissions have accelerated, so we are storing up problems for ourselves in the future." The IPCC report, seen by The Sunday Telegraph, has been handed to the Government for review before publication. It warns that carbon dioxide emissions have risen during the past five years by three per cent, well above the 0.4 per cent a year average of the previous two decades. The authors also state that the climate is almost certain to warm by at least 1.5 C during the next 100 years. Such a rise would be enough to take average summer temperatures in Britain to those seen during the 2003 heatwave, when August temperatures reached a record-breaking 38 C. Unseasonable warmth this year has left many Alpine resorts without snow by the time the ski season started. Britain can expect more storms of similar ferocity to those that wreaked havoc across the country last week, even bringing a tornado to north-west London. The IPCC has been forced to halve its predictions for sea-level rise by 2100, one of the key threats from climate change. It says improved data have reduced the upper estimate from 34 in to 17 in. It also says that the overall human effect on global warming since the industrial revolution is less than had been thought, due to the unexpected levels of cooling caused by aerosol sprays, which reflect heat from the sun. Large amounts of heat have been absorbed by the oceans, masking the warming effect. Prof Rick Battarbee, the director of the Environmental Change Research Centre at University College London, warned these masking effects had helped to delay global warming but would lead to larger changes in the future. He said: "The oceans have been acting like giant storage heaters by trapping heat and carbon dioxide. They might be bit of a time-bomb as they have been masking the real effects of the carbon dioxide we have been releasing into the atmosphere. "People are very worried about what will happen in 2030 to 2050, as we think that at that point the oceans will no longer be able to absorb the carbon dioxide being emitted. It will be a tipping point and that is why it is now critical to act to counter any acceleration that will occur when this happens." The report paints a bleak picture for future generations unless greenhouse gas emissions are reduced. It predicts that the climate will warm by 0.2 C a decade for the next two decades if emissions continue at current levels. The report states that snow cover in mountainous regions will contract and permafrost in polar regions will decline. However, Julian Morris, executive director of the International Policy Network, urged governments to be cautious. "There needs to be better data before billions of pounds are spent on policy measures that may have little impact," he said. |
Thursday, December 7, 2006
Ignoring Feedback in Global Warming
The PR machine that is the Chicken Little Industry got Reuters to do a story on research by several U.S. university scientists, who issued a report that says, according to Reuters, "Global warming will stifle life-giving microscopic plants that live in the surface layer of the oceans, cutting marine food production and accelerating climate change." Emphasis is mine, because I used to think scientific predictions were made based on statistical probabilities and confidence intervals. But Reuters managed to get "will" from the report. I hope the scientists themselves were a little more nuanced.
According to these latest scientists, man-made global warming is causing the oceans to lose phytoplankton, which absorb some 50% of atmospheric carbon dioxide, the primary global warming culprit according to those deriving their living from proclaiming from the rooftops that the world is ending.
Researchers at the Scripps Center for Oceanography agree that the amount of phytoplankton in the oceans is key to global warming. According to their report published in the Journal of Geophysical Research, the "radiation absorbed by phytoplankton raises global average temperatures by 0.1 to 0.6 degrees Fahrenheit." The report concluded that climate models need to take into account this global warming effect of phytoplankton. In fact, the Scripps scientists warn against any attempts to increase populations of phytoplankton in the hope they will absorb more CO2 from the atmosphere because of the concurrent radiation absorption warming effect.
So, scientists have found:
1. A positive correlation between increased amounts of oceanic phytoplankton and global temperature; and
2. A negative correlation between increased amounts of oceanic phytoplankton and global temperature.
Consider, also a further study that says that phytoplankton release dimethyl sulfide when eating CO2 and absorbing heat. This dimethyl sulfide causes greater cloud formation, thereby causing reflective cooling of the surface. Yet another feedback mechanism.
Yet, oddly, Reuters doesn't uncover the Scripps Center report or the dimethyl sulfide issue or ask questions about contradictions with the latest scare screed. Clearly, that would undercut the attempt to frighten the public into abandoning capitalism and voting for Al Gore.
Dr Sam Iacobellis explains what the media and Al Gore don't understand:
This just shows how intricate the climate system is. It's like a ball of yarn all pushed together. It's difficult to unpiece the climate or put together what might happen in the future when all these things act together. One by itself may not be that important, but when thousands of these small things act together, what then?As Mr. Gore has concluded, " Ceteris paribus, the sky's falling."
But complex systems effected by chemistry, biology, geology, astronomy, particle physics and other things can never be reduced to ceteris paribus and still provide an explanation for observable climate data or a reliable prediction of future weather.
But you are asked to abandon your economy while those asking jet around in their private planes and ask nothing of the most populous nations in the world.
Southern Ocean Could Slow Global Warming
Southern Ocean Could Slow Global Warming
The Southern Hemisphere westerly winds have moved southward in the last 30 years. A new climate model predicts that as the winds shift south, they can do a better job of transferring heat and carbon dioxide from the surface waters surrounding Antarctica into the deeper, colder waters.
The new finding surprised the scientists, said lead researcher Joellen L. Russell. "We think it will slow global warming. It won't reverse or stop it, but it will slow the rate of increase."
The new model Russell and her colleagues developed provides a realistic simulation of the Southern Hemisphere westerlies and Southern Ocean circulation.
Previous climate models did not have the winds properly located. In simulations of present-day climate, those models distorted the ocean's response to future increases in greenhouse gases.
"Because these winds have moved poleward, the Southern Ocean around Antarctica is likely to take up 20 percent more carbon dioxide than in a model where the winds are poorly located," said Russell, an assistant professor of geosciences at The University of Arizona in Tucson.
"More heat stored in the ocean means less heat stored in the atmosphere. That's also true for carbon dioxide, the major greenhouse gas."
"But there are consequences," Russell said. "This isn't an unqualified good, even if more carbon dioxide and heat goes into the ocean."
As the atmosphere warms, storing more heat in the ocean will cause sea levels to rise even faster as the warmed water expands, she said. Adding more CO2 to the oceans will change their chemistry, making the water more acidic and less habitable for some marine organisms.
Russell and her colleagues conducted the study while she was a researcher at Princeton University and the National Oceanic and Atmospheric Administration's Geophysical Fluid Dynamics Laboratory in Princeton, N.J.
Her co-authors on the article, "The Southern Hemisphere Westerlies in a Warming World: Propping open the Door to the Deep Ocean," are GFDL researchers Keith W. Dixon, Anand Gnanadesikan, Ronald J. Stouffer and J.R . Toggweiler. The article will be published in the December 15 issue of the Journal of Climate.
The current set of computer models that scientists use to predict future climate differ in the degree to which heat is sequestered by the Southern Ocean. The models vary in how they represent the behavior of the Southern Hemisphere Westerlies and the Antarctic Circumpolar Current, the largest current on the planet.
The team's model does a better job of depicting the location and observed southward shift of the Southern Hemisphere atmospheric winds than do previous global climate circulation models. The new model developed at GFDL shows that the poleward shift of the westerlies intensifies the strength of the winds as they whip past the tip of South America and circumnavigate Antarctica.
"It's like a huge blender," Russell said as she held up a globe and demonstrated how the winds whirl around the southernmost continent. Those winds, she said, propel the Antarctic Circumpolar Current. The current drives the upwelling of cold water from more than two miles deep. The heavy, cold water comes to the surface and then sinks back down, carrying the carbon dioxide and heat with it.
The new model forecasts this shift in the winds will continue into the future as greenhouse gases increase.
Stouffer said, "The poleward intensification of the westerlies will allow the ocean to remove additional heat and anthropogenic carbon dioxide from the atmosphere. Thus, the deep ocean has the potential to slow the atmospheric warming through the increased storage of heat and carbon."
The team's next step will be figuring out how warming, ice-melt and ongoing shifts in the Southern Hemisphere westerlies will affect the biogeochemistry of the Southern Ocean and the global budgets for heat and carbon dioxide.
Source: University of Arizona
Global warming will reduce ocean productivity, marine life
A 10-year, satellite-based analysis has shown for the first time that primary biological productivity in the oceans - the growth of phytoplankton that forms the basis for the rest of the marine food chain - is tightly linked to climate change, and would be reduced by global warming.
The study, published this week in the journal Nature by researchers from Oregon State University and five other institutions, found that on a global scale, a warmer climate could cause a rapid, overall reduction in marine life.
This clearly showed that overall ocean productivity decreases when the climate warms, said lead author Michael Behrenfeld, an OSU professor of botany and expert on remote sensing of marine biology.
There is significant regional variability, with some areas showing enhanced production and some area losses, Behrenfeld said. But on a global basis there is an inverse relationship increased temperatures cause decreased marine phytoplankton production.
This climate response can be traced to increased stratification in the oceans, the study showed. When the ocean surface warms, it essentially becomes lighter than the cold, dense water below, which is loaded with nutrients. This process effectively separates phytoplankton in the surface layer - which need light for photosynthesis - from the nutrients below them, which they also need for growth.
The satellite data used in the study were from NASA's SeaWiFS satellite, or Sea-viewing Wide-Field-of-view Sensor. Since its launch in 1997, SeaWiFS has measured changes in the color of the ocean - as more and more phytoplankton are added, the color shifts from blue toward green. By studying these color changes from space, scientists can calculate how much phytoplankton pigment is in the water, relate this to photosynthetic rate, and correlate these changes to simultaneous changes in climate.
The first climate-driven change in ocean production measured in this study occurred between 1997 and 1999, when the oceans were recovering from one of the strongest El Nino events on record. With the end of the El Nino, global climate began to cool and there was a surge in ocean phytoplankton productivity that peaked in late 1999.
The second climate event was a long-term warming trend that started in 2000 and continues today. Over this period, the ocean sea surface became overall warmer and more stratified, and phytoplankton productivity went down almost in lockstep at a rate of about 190 million tons of carbon a year. On a regional scale, the decreases in production often exceeded 30 percent.
Despite their microscopic size, ocean phytoplankton are responsible for about half of the photosynthesis on Earth, a process that removes carbon dioxide from the atmosphere and converts it into organic carbon to fuel nearly every ocean ecosystem.
Compared to terrestrial land plants, however, phytoplankton use a very small amount of biomass to convert large amounts of carbon, because they are eaten by predators about as quickly as they grow. The entire global phytoplankton biomass is consumed every two to six days, in contrast to land plants that might have turnover rates of a year to hundreds of years.
This very fast turnover, along with the fact that phytoplankton are limited to just a thin veneer of the ocean surface where there is enough sunlight to sustain photosynthesis, makes them very responsive to changes in climate, Behrenfeld said. This was why we could relate productivity changes to climate variability in only a 10-year record. Such connections would be much harder to detect from space for terrestrial plant biomass.
Results of the study may provide important insight into how ocean biology might respond to sustained global warming, the researchers said. ⌠A common prediction among global climate models is that warming will cause ocean production to decrease at mid-latitudes and low latitudes, due to intensified stratification, Behrenfeld said, This is precisely the response we observed.
Climate models also predict long term global warming will cause enhanced phytoplankton production near the poles, because of longer growing seasons, and shifts in the organisms dominating different ecosystems across the globe. These predictions have not yet been confirmed by satellite ocean measurements, and detection of them may require a longer record or advances in satellite technology.
Climate not only influences ocean biology, but ocean biology influences climate.
Rising levels of carbon dioxide in the atmosphere are a key part of global warming, Behrenfeld said. This study shows that as the climate warms, phytoplankton production goes down, but this also means that carbon dioxide uptake by ocean plants will decrease. That would allow carbon dioxide to accumulate more rapidly in the atmosphere, making the problem worse.
Better understanding this feedback mechanism which compounds global warming is a top priority for study, the researchers say.
By Oregon State University
Warmer climate means less plankton, big problems for ocean populations
Wednesday, December 6, 2006 03 12 PM
When the climate warms, there is a drop in the abundance of the ocean's phytoplankton, the tiny plants that feed krill, fish and whales, according to scientists who say the just-released research offers new clues to future life under global warming.
Ocean temperatures bounce up and down, but over the past century they have been warming along with the atmosphere. Nine years of NASA satellite data released today in the journal Nature show that the growth of phytoplankton drops in warm ocean years and increases in cooler ocean years.
Over the past decades, scientists have linked declining plankton numbers to warm-water El Nino years, which set off a domino effect of fewer krill and young fish, leading to failed reproduction of seabirds and even deaths of seals and sea lions.
"We've seen it on a regional scale. What's amazing is this is the first time we see it on a global scale. Now we have an inkling what will now happen to the ocean's biology in future climates,'' said Dave Siegel, a professor of marine science at UC Santa Barbara and a study author.
The scientists report that the association between warmer ocean waters and fewer plankton was born out in three-quarters of the ocean.
When the climate warms, the ocean's upper layer where the phytoplankton proliferate becomes separated from the colder ocean water below. The ocean waters then can't mix as well, and nutrients in the deeper, colder waters don't get up to the phytoplankton that uses them as a sort of fertilizer.
The lack of phytoplankton means less food for fish and other ocean life, but it also means less phytoplankton to absorb carbon dioxide, a greenhouse gas.
The research is the result of years of collaboration among UC Santa Barbara, Oregon State University, Princeton University, Rutgers University, University of Maine and NASA's Goddard Space Flight Center in Greenbelt, Md.
E-mail Jane Kay at jkay@sfchronicle.com.