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IPCC Understates Case for Man-Made Warming: Study

Review says global warming is man-made

The Financial Times, March 4, 2010

The case for man-made global warming is even stronger than the Intergovernmental Panel on Climate Change maintained in its official assessments, according to the first scientific review published since December’s Copenhagen conference and subsequent attacks on the IPCC’s credibility.

An international research team led by the UK Met Office spent the past year analysing more than 100 recent scientific papers to update the last IPCC assessment, released in 2007.

Although the review itself preceded the sceptics’ assault on climate science over the past three months, its launch in London on Thursday marks a resumption of the campaign by mainstream scientists to show that man-made releases of greenhouse gases are causing potentially dangerous global warming.

“The fingerprint of human influence has been detected in many different aspects of observed climate changes,” said Peter Stott, head of climate monitoring at the Met Office Hadley Centre for Climate Research. “Natural variability, from the sun, volcanic eruptions or natural cycles, cannot explain recent warming.”

The review, published in the journal Wiley Interdisciplinary Reviews: Climate Change, found several “fingerprints” of warming that had not been established by the time of the last IPCC assessment but were now unambiguously present.

One is human-induced climate in the Antarctic, the last continent where regional warming has been demonstrated.

There is also new evidence of warming in the oceans, which is having several effects. The subtropical Atlantic is becoming saltier; the extra salinity could in turn alter ocean currents.

Another effect of ocean warming is increasing evaporation, leading to more humidity in the atmosphere and changing rainfall patterns.

“The whole water cycle is changing,” said Mr. Stott. “The wet regions are tending to get wetter and the dry regions are getting dryer.”

Globally, this means less rainfall in the tropics and more at higher latitudes, although Mr. Stott said there was much regional variation in the pattern, which scientists were still working to make sense of.

The review is based on a forensic comparison of the pattern of changes expected from man-made warming with those that would result from other factors such as changing solar radiation and purely natural variations.

A separate study by Russian and US scientists, published today in the journal Science, shows that methane, a powerful greenhouse gas, is escaping from the seafloor of the warming Arctic Ocean more rapidly than had been suspected.

http://www.ft.com/cms/s/0/9513bee6-27b3-11df-863d-00144feabdc0,dwp_uuid=728a07a0-53bc-11db-8a2a-0000779e2340.html

New Study: Humans Are Causing Climate Change

Redorbit.com, March 7, 2010

The UK Met office says that it is becoming clearer that human activities are causing climate change.

The office says that the evidence is stronger now than when the Intergovernmental Panel on Climate Change carried out its last assessment in 2007. The review has assessed 110 research papers on the subject.

The analysis, which was published in the Wiley Interdisciplinary Reviews Climate Change Journal, said the Earth is changing rapidly, most likely due to greenhouse gases. The IPPC's report in 2007 said there was "unequivocal" evidence that Earth was warming, most likely because of the burning of fossil fuels.

According to this new assessment by Dr. Peter Stott, along with colleagues at the U.K. Met Office, the evidence that human actives are responsible for a rise in temperatures has increased since the IPPC report.

The study has come during a time that some question the entire basis of climate change after recent controversies over the handling of research findings by the IPPC and the Climate Research Unit at the University of East Anglia. Stott denies the study was published as part of a fight back by the climate research community.

"We started writing this paper a year ago. I think it's important to communicate to people what the science is showing and that's why I'm talking about this paper."

The study found that changes in Arctic sea ice, atmospheric moisture, saltiness of parts of the Atlantic Ocean and temperature changes in the Antarctic are consistent with human influence on our climate.

"What this study shows is that the evidence has strengthened for human influence on climate and we know that because we've looked at evidence across the climate system and what this shows very clearly is a consistent picture of a warming world," said Stott.

This study brings together research from a wide variety of disciplines.

"We hadn't [until now] looked in detail at how the climate system was changing," says Stott. "[Our paper looks at] not just the temperatures but also the reducing Arctic sea ice and it includes changing rainfall patterns and it includes the fact that the atmosphere is getting more humid."

"And all these different aspects of the climate system are adding up to a picture of the effects of a human influence on our climate."

The study by the Met Office said that it was harder to decipher a definitive link between climate change and individual extreme weather conditions, although models predicted that extreme events were more likely.

The report concludes "extremes pose a particular challenge, since rare events are by definition, poorly sampled in the historical record and many challenges remain for robustly attributing regional changes in extreme events such as droughts, floods and hurricanes."

http://www.redorbit.com/news/display/?id=1832779