The Associated Press

WASHINGTON — Have you heard that the world is now cooling instead of warming? You may have seen some news reports on the Internet or heard about it from a provocative new book. 

Only one problem: It’s not true, according to an analysis of the numbers done by several independent statisticians for The Associated Press 

The case that the Earth might be cooling partly stems from recent weather. Last year was cooler than previous years. It’s been a while since the super-hot years of 1998 and 2005. So is this a longer climate trend or just weather’s normal ups and downs?

In a blind test, the AP gave temperature data to four independent statisticians and asked them to look for trends, without telling them what the numbers represented. The experts found no true temperature declines over time.

“If you look at the data and sort of cherry-pick a micro-trend within a bigger trend, that technique is particularly suspect,” said John Grego, a professor of statistics at the University of South Carolina.

Yet the idea that things are cooling has been repeated in opinion columns, a BBC news story posted on the Drudge Report and in a new book by the authors of the best-seller “Freakonomics.” Last week, a poll by the Pew Research Center found that only 57 percent of Americans now believe there is strong scientific evidence for global warming, down from 77 percent in 2006.

Global warming skeptics base their claims on an unusually hot year in 1998. Since then, they say, temperatures have dropped — thus, a cooling trend. But it’s not that simple.

Since 1998, temperatures have dipped, soared, fallen again and are now rising once more. Records kept by the British meteorological office and satellite data used by climate skeptics still show 1998 as the hottest year. However, data from the National Oceanic and Atmospheric Administration and NASA show 2005 has topped 1998. Published peer-reviewed scientific research generally cites temperatures measured by ground sensors, which are from NOAA, NASA and the British, more than the satellite data.

The recent Internet chatter about cooling led NOAA’s climate data center to re-examine its temperature data. It found no cooling trend.

“The last 10 years are the warmest 10-year period of the modern record,” said NOAA climate monitoring chief Deke Arndt. “Even if you analyze the trend during that 10 years, the trend is actually positive, which means warming.”

The AP sent expert statisticians NOAA’s year-to-year ground temperature changes over 130 years and the 30 years of satellite-measured temperatures preferred by skeptics and gathered by scientists at the University of Alabama in Huntsville.

Statisticians who analyzed the data found a distinct decades-long upward trend in the numbers, but could not find a significant drop in the past 10 years in either data set. The ups and downs during the last decade repeat random variability in data as far back as 1880.

Saying there’s a downward trend since 1998 is not scientifically legitimate, said David Peterson, a retired Duke University statistics professor and one of those analyzing the numbers.

Identifying a downward trend is a case of “people coming at the data with preconceived notions,” said Peterson, author of the book “Why Did They Do That? An Introduction to Forensic Decision Analysis.”

One prominent skeptic said that to find the cooling trend, the 30 years of satellite temperatures must be used. The satellite data tends to be cooler than the ground data. And key is making sure 1998 is part of the trend, he added.

It’s what happens within the past 10 years or so, not the overall average, that counts, contends Don Easterbrook, a Western Washington University geology professor and global warming skeptic.

“I don’t argue with you that the 10-year average for the past 10 years is higher than the previous 10 years,” said Easterbrook, who has self-published some of his research. “We started the cooling trend after 1998. You’re going to get a different line depending on which year you choose.

“Should not the actual temperature be higher now than it was in 1998?” Easterbrook asked. “We can play the numbers games.”

That’s the problem, some of the statisticians said.

Grego produced three charts to show how choosing a starting date can alter perceptions. Using the skeptics’ satellite data beginning in 1998, there is a “mild downward trend,” he said. But doing that is “deceptive.”

The trend disappears if the analysis starts in 1997. And it trends upward if you begin in 1999, he said.

Apart from the conflicting data analyses is the eyebrow-raising new book title from Steven D. Levitt and Stephen J. Dubner, “Super Freakonomics: Global Cooling, Patriotic Prostitutes and Why Suicide Bombers Should Buy Life Insurance.”

A line in the book says: “Then there’s this little-discussed fact about global warming: While the drumbeat of doom has grown louder over the past several years, the average global temperature during that time has in fact decreased.”

That led to a sharp rebuke from the Union of Concerned Scientists, which said the book mischaracterizes climate science with “distorted statistics.”

Levitt, a University of Chicago economist, said he does not believe there is a cooling trend. He said the line was just an attempt to note the irony of a cool couple of years at a time of intense discussion of global warming. Levitt said he did not do any statistical analysis of temperatures, but “eyeballed” the numbers and noticed 2005 was hotter than the last couple of years. Levitt said the “cooling” reference in the book title refers more to ideas about trying to cool the Earth artificially.

Statisticians say that in sizing up climate change, it’s important to look at moving averages of about 10 years. They compare the average of 1999-2008 to the average of 2000-2009. In all data sets, 10-year moving averages have been higher in the last five years than in any previous years.

“To talk about global cooling at the end of the hottest decade the planet has experienced in many thousands of years is ridiculous,” said Ken Caldeira, a climate scientist at the Carnegie Institution at Stanford.

Ben Santer, a climate scientist at the Department of Energy’s Lawrence Livermore National Lab, called it “a concerted strategy to obfuscate and generate confusion in the minds of the public and policymakers” ahead of international climate talks in December in Copenhagen.

President Barack Obama weighed in on the topic Friday at MIT. He said some opponents “make cynical claims that contradict the overwhelming scientific evidence when it comes to climate change — claims whose only purpose is to defeat or delay the change that we know is necessary.”

Earlier this year, climate scientists in two peer-reviewed publications statistically analyzed recent years’ temperatures against claims of cooling and found them not valid.

Not all skeptical scientists make the flat-out cooling argument.

“It pretty much depends on when you start,” wrote John Christy, the Alabama atmospheric scientist who collects the satellite data that skeptics use. He said in an e-mail that looking back 31 years, temperatures have gone up nearly three-quarters of a degree Fahrenheit (four-tenths of a degree Celsius). The last dozen years have been flat, and temperatures over the last eight years have declined a bit, he wrote.

Oceans, which take longer to heat up and longer to cool, greatly influence short-term weather, causing temperatures to rise and fall temporarily on top ofthe overall steady warming trend, scientists say. The biggest example of that is El Nino.

El Nino, a temporary warming of part of the Pacific Ocean, usually spikes global temperatures, scientists say. The two recent warm years, both 1998 and 2005, were El Nino years. The flip side of El Nino is La Nina, which lowers temperatures. A La Nina bloomed last year and temperatures slipped a bit, but 2008 was still the ninth hottest in 130 years of NOAA records.

Of the 10 hottest years recorded by NOAA, eight have occurred since 2000, and after this year it will be nine because this year is on track to be the sixth-warmest on record.

The current El Nino is forecast to get stronger, probably pushing global temperatures even higher next year, scientists say. NASA climate scientist Gavin Schmidt predicts 2010 may break a record, so a cooling trend “will be never talked about again.”

Reprinted from The Atlanta Journal-Constitution.

Rivers in some of the world’s most populous regions are losing water, according to a comprehensive study of global stream flows.

The research, led by scientists at the National Center for Atmospheric Research (NCAR) in Boulder, Colo., suggests that the reduced flows in many cases are associated with climate change, and could potentially threaten future supplies of food and water.

The results will be published May 15 in the American Meteorological Society’s Journal of Climate. The research was supported by the National Science Foundation (NSF), NCAR’s sponsor.

“The distribution of the world’s fresh water, already an important topic,” says Cliff Jacobs of NSF’s Division of Atmospheric Sciences, “will occupy front and center stage for years to come in developing adaptation strategies to a changing climate.”

The scientists, who examined stream flows from 1948 to 2004, found significant changes in about one-third of the world’s largest rivers. Of those, rivers with decreased flow outnumbered those with increased flow by a ratio of about 2.5 to 1.

Several of the rivers channeling less water serve large populations, including the Yellow River in northern China, the Ganges in India, the Niger in West Africa and the Colorado in the southwestern United States.

In contrast, the scientists reported greater stream flows over sparsely populated areas near the Arctic Ocean, where snow and ice are rapidly melting.

“Reduced runoff is increasing the pressure on freshwater resources in much of the world, especially with more demand for water as population increases,” says NCAR scientist Aiguo Dai, the lead author of the journal paper. “Freshwater being a vital resource, the downward trends are a great concern.”

Many factors may affect river discharge, including dams and the diversion of water for agriculture and industry.

The researchers found, however, that the reduced flows in many cases appear to be related to global climate change, which is altering precipitation patterns and increasing the rate of evaporation.

The results are consistent with previous research by Dai and others showing widespread drying and increased drought over many land areas.

The study raises wider ecological and climate concerns.

Discharge from the world’s great rivers results in deposits of dissolved nutrients and minerals into the oceans. The freshwater flow also affects global ocean circulation patterns, which are driven by changes in salinity and temperature, and which play a vital role in regulating the world’s climate.

Although the recent changes in freshwater discharge are relatively small and may only have impacts around major river mouths, Dai said the freshwater balance in the global oceans and over land needs to be monitored for long-term changes.

Scientists have been uncertain about the impacts of global warming on the world’s major rivers. Studies with computer models show that many of the rivers outside the Arctic could lose water because of decreased precipitation in the mid- and lower latitudes, and an increase in evaporation caused by higher temperatures.

Earlier, less comprehensive analyses of major rivers had indicated, however, that global stream flow was increasing.

Dai and his co-authors analyzed the flows of 925 of the planet’s largest rivers, combining actual measurements with computer-based stream flow models to fill in data gaps.

The rivers in the study drain water from every major landmass except Antarctica and Greenland and account for 73 percent of the world’s total stream flow.

Overall, the study found that, from 1948 to 2004, annual freshwater discharge into the Pacific Ocean fell by about 6 percent, or 526 cubic kilometers–approximately the same volume of water that flows out of the Mississippi River each year.

The annual flow into the Indian Ocean dropped by about 3 percent, or 140 cubic kilometers. In contrast, annual river discharge into the Arctic Ocean rose about 10 percent, or 460 cubic kilometers.

In the United States, the Columbia River’s flow declined by about 14 percent during the 1948-2004 study period, largely because of reduced precipitation and higher water usage in the West.

The Mississippi River, however, has increased by 22 percent over the same period because of greater precipitation across the Midwest since 1948.

Some rivers, such as the Brahmaputra in South Asia and the Yangtze in China, have shown stable or increasing flows. But they could lose volume in future decades with the gradual disappearance of the Himalayan glaciers feeding them, the scientists say.

“As climate change inevitably continues in coming decades, we are likely to see greater impacts on many rivers and the water resources that society has come to rely on,” says NCAR scientist Kevin Trenberth, a co-author of the paper.

Reposted from the National Science Foundation.

23/03/2009 2:01:00 PM

Quietly in public, loudly in private, climate scientists everywhere are saying the same thing: it’s over.

The years in which more than 2degrees of global warming could have been prevented have passed, the opportunities squandered by denial and delay.

On current trajectories we’ll be lucky to get away with 4degrees.

Mitigation (limiting greenhouse gas pollution) has failed, now we must adapt to what nature sends our way. If we can.

This was the repeated whisper at the climate change conference in Copenhagen earlier this month.

It is more or less what Bob Watson, the environment department’s chief scientific adviser, has been telling the British government.

It is the obvious, if unspoken, conclusion of scores of scientific papers.

Recent work by scientists at the Tyndall Centre for Climate Change Research, for instance, suggests that even global cuts of 3per cent a year, starting in 2020, could leave us with 4 degrees of warming by the end of the century.

At the moment, emissions are heading in the opposite direction at roughly the same rate.

If this continues, what does it mean? Six? Eight? Ten degrees? Who knows?

Faced with such figures, I can’t blame anyone for throwing up their hands. But before you succumb to this fatalism, let me talk you through the options.

Yes, it is true mitigation has so far failed. Sabotaged by Bill Clinton, abandoned by George W. Bush, attended halfheartedly by the other rich nations, the global climate talks have so far been a total failure.

The targets they have set bear no relation to the science and are negated anyway by loopholes and false accounting.

Nations such as Britain, which is meeting its obligations under the Kyoto protocol, have succeeded only by outsourcing it’s pollution to other countries.

And nations such as Canada, which is flouting its obligations, face no meaningful sanctions.

Lord Stern made it too easy, he appears to have underestimated the costs of mitigation.

As the professor of energy policy Dieter Helm has shown, Stern’s assumption that our consumption can continue to grow while our emissions fall is implausible. To have any hope of making substantial cuts we have to reduce our consumption and transfer resources to countries such as China to pay for the switch to low carbon technologies.

As professor Helm says, ”there is not much in the study of human nature and indeed human biology to give support to the optimist”.

But we cannot abandon mitigation unless we have a better option, but we don’t.

If you think our attempts to prevent emissions are futile, take a look at our efforts to adapt.

Germany is spending $US600million ($A871million) on a new sea wall for Hamburg and this money was committed before the news came through that sea-level rises this century could be two or three times as great as the Intergovernmental Panel on Climate Change has predicted.

The Netherlands will spend $3.19billion on dykes between now and 2015 and again, they are likely to be inadequate.

The UN suggests rich countries should be transferring between $72billion and $109billion per year to poor countries now, to help them cope with climate change.

But nothing like this is happening.

Rich nations have promised $26billion to help the poor nations adapt to climate change during the past seven years, but they have disbursed only 5per cent.

Oxfam has made a compelling case for how adaptation should be funded. Nations should pay according to the amount of carbon they produce per capita, coupled with their position on the human development index.

On this basis, the US should supply more than 40per cent of the money and the European Union over 30per cent, with Japan, Canada, Australia and Korea making up the balance. But what are the chances of getting them to cough up? There’s a limit to what this money could buy anyway.

The Intergovernmental Panel on Climate Change says that ”global mean temperature changes greater than 4degrees above 1990-2000 levels” would ”exceed … the adaptive capacity of many systems”.

At this point there’s nothing you can do, for instance, to prevent the loss of ecosystems, the melting of glaciers and the disintegration of major ice sheets.

Elsewhere it spells out the consequences more starkly. Global food production, it says, is ”very likely to decrease above about 3degrees”. Buy your way out of that.

And it doesn’t stop there. The IPCC also finds that, above 3degrees of warming, the world’s vegetation will become ”a net source of carbon”.

This is just one of the climate feedbacks triggered by a high level of warming. Four degrees might take us inexorably to 5degrees or 6degrees, the end for humans of just about everything.

Until recently, scientists spoke of carbon concentrations and temperatures peaking and then falling back.

But a recent paper in the Proceedings of the National Academy of Sciences shows that ”climate change … is largely irreversible for 1000 years after emissions stop”.

Even if we were to cut carbon emissions to zero today, by the year 3000 our contribution to atmospheric concentrations would decline by just 40per cent. High temperatures would remain more or less constant until then. If we produce it, we’re stuck with it.

In the rich nations we will muddle through, for a few generations, and spend nearly everything we have on coping. But where the money is needed most there will be nothing.

The ecological debt the rich world owes to the poor will never be discharged, just as it has never accepted that it should offer reparations for the slave trade and for the pillage of gold, silver, rubber, sugar and all the other commodities taken without due payment.

Finding the political will for crash cuts in carbon production is improbable. But finding the political will when the disasters have already begun to spend adaptation money on poor nations rather than on ourselves will be impossible.

The world won’t adapt and can’t adapt, the only adaptive response to a global shortage of food is starvation.

Of the strategies it is mitigation, not adaptation, which turns out to be the most feasible option.

Yes, it might already be too late even if we reduced emissions to zero tomorrow to prevent more than 2degreesC of warming. But we cannot behave as if it is, for in doing so we make the prediction come true.

Tough as this fight may be, improbable as success might seem, we cannot afford to surrender. Guardian

Reprinted From: 

http://www.canberratimes.com.au/news/opinion/editorial/general/opportunity-for-2-degrees-lost/1466204.aspx?storypage=0

“The vastness of our oceans may have engendered a sense of complacency about potential impacts from global climate change,” said Jane Lubchenco, the Wayne and Gladys Valley Chair of Marine Biology at Oregon State University, who moderated the panel. “The world’s oceans are undergoing profound physical, chemical and biological changes whose impacts are just beginning to be felt.”

Panelist Gretchen Hofmann, a molecular physiologist at the University of California, Santa Barbara, describes the situation as “multiple jeopardy.”

“Ocean ecosystems are facing new stresses and new combinations of stress,” Hofmann said. “The water is warmer, circulation patterns are changing in unpredictable ways, and oceans are becoming acidic.”

Rising greenhouse gas emissions are warming the world’s oceans and providing yet a new threat to coral reefs, which already are among the most threatened of all marine ecosystems, the panelists say. Even modest warming of a degree or two above normal maximum temperatures can cause a breakdown in the relationship between corals and their symbiotic algae, zooxanthellae, said Nancy Knowlton, a marine biologist with the Smithsonian Institution.

Without zooxanthellae corals appear white, or “bleached,” and grow more slowly. They also are more susceptible to disease and may not reproduce. In 1998 there were worldwide mass bleaching events, Knowlton pointed out, affecting 80 percent of the corals in the Indian Ocean, 20 percent of which died. In 2005, severe bleaching occurred over much of the Caribbean as a result of overly warm water temperatures.

“We have already lost some 80 percent of the reef corals in the Caribbean over the last three decades, and losses in the Pacific Ocean also are widespread and severe,” Knowlton said. “Reefs are like cities, with some parts growing and some parts being destroyed, and only when net growth is positive can reefs persist. These reefs already are under threat to overfishing and local pollution and unless drastic action to reduce greenhouse gas emissions is taken soon, these reefs will cease to exist as we know them.”

These same greenhouse gas emissions also are creating dramatic buildup of atmospheric carbon dioxide, which is rapidly making the world’s oceans more acidic, said panelist Scott Doney of the Woods Hole Oceanographic Institution. Current CO2 levels of 380 parts per million already are 30 percent higher than pre-industrial values and many scientific models predict that those rates will triple by the end of the century under “business as usual” scenarios.

While much of the scientific attention on ocean acidification has looked at the impact of coral reefs, the potential danger to other marine ecosystems is equally severe, Doney said.

“Ocean acidification harms plants and animals that form shells from calcium carbonate,” he said. “Calcifying organisms include not just corals, but many plankton, pteropods (marine snails), clams and oysters, and lobsters. Many of these organisms provide critical food sources or habitats for other organisms and the impact of acidification on food webs and higher trophic levels is not well understood.

“Newly emerging evidence suggests that larval and juvenile fish may also be susceptible to changes in ocean pH levels,” Doney added. “Ocean acidification is rapidly becoming a real problem.”

Michael Behrenfeld, an oceanographer from Oregon State University, is studying relationships between climate and the global activity of ocean plants called phytoplankton.

“Phytoplankton are of tremendous human importance because their photosynthesis yields oxygen for us to breathe and they are the base of the ocean food webs that support our global fisheries,” Behrenfeld said. “Using NASA satellites, we can track changes in phytoplankton on a global basis and what we find is that warming ocean temperatures are linked to decreasing photosynthesis. Satellites are one of the most important tools we have for understanding the link between climate and ocean biology because they provide measurements of the whole planet on a daily basis, which could never be accomplished by ship.

“Unfortunately,” he added, “it is at this very time when we need satellites most that we are facing the end of NASA ocean biology satellites because of budget cutbacks or new priorities. This is a serious issue that needs to be addressed.

“Instead of facing the end of these critical missions and becoming blind to the changes occurring in our oceans,” Behrenfeld said, “we should be building even better ones to see more clearly than we have in the past, and to gauge the potential consequences of climate change on ocean productivity.”

The panelists also called for greater investment in ocean observing systems that would allow scientists to better measure changing in the ocean ecosystem, including large-scale circulation and coastal upwelling systems around the world. Klaus Keller of Penn State University reported on the economic costs and benefits of effective ocean observing systems to detect changes in the north Atlantic Meridional Overturning Circulation.

Jack Barth, an oceanographer at Oregon State University, reported on the hypoxia events that have plagued the Pacific Northwest coast since 2000. These low-oxygen zones in the near-shore are unprecedented over the last five decades of scientific observation and likely linked to stronger, more persistent winds that are expected to occur with global warming. The California Current System provides a case study for similar changes in coastal upwelling zones off South America, southern Africa and northern Africa, Barth said.

“One of the things we’ve observed is how wind patterns have changed and greatly affected upwelling,” Barth said. “Two decades ago, the winds would last for three or four days, and then subside. Now they persist for 20 to 40 days before settling down. This creates significant impacts on upwelling and biological productivity, but these impacts can swing wildly from one extreme to another and have been difficult to predict.”

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The AAAS symposium was organized by the Partnership for Interdisciplinary Studies of Coastal Oceans, a multi-university research effort headquartered at Oregon State University and funded by the David and Lucile Packard Foundation, the Gordon and Betty Moore Foundation, the National Science Foundation and other sources.