Global warming 'confirmed' by independent study

Richard Black BBC News 20 Oct 11;

The Earth's surface really is getting warmer, a new analysis by a US scientific group set up in the wake of the "Climategate" affair has concluded.

The Berkeley Earth Project has used new methods and some new data, but finds the same warming trend seen by groups such as the UK Met Office and Nasa.

The project received funds from sources that back organisations lobbying against action on climate change. "Climategate", in 2009, involved claims global warming had been exaggerated.

Emails of University of East Anglia (UEA) climate scientists were hacked, posted online and used by critics to allege manipulation of climate change data.
Fresh start

The Berkeley group says it has also found evidence that changing sea temperatures in the north Atlantic may be a major reason why the Earth's average temperature varies globally from year to year.

The project was established by University of California physics professor Richard Muller, who was concerned by claims that established teams of climate researchers had not been entirely open with their data.

He gathered a team of 10 scientists, mostly physicists, including such luminaries as Saul Perlmutter, winner of this year's Nobel Physics Prize for research showing the Universe's expansion is accelerating.

Funding came from a number of sources, including charitable foundations maintained by the Koch brothers, the billionaire US industrialists, who have also donated large sums to organisations lobbying against acceptance of man-made global warming.
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Our biggest surprise was that the new results agreed so closely with the warming values published previously”

Richard Muller Berkeley group founder

"We were concerned that the climate scientists were not putting all their data into the public domain, whether using Freedom of Information rules or anything else," he told BBC News.

"Science should be open, and data should be open, as a matter of principle."

The group's work also examined claims from "sceptical" bloggers that temperature data from weather stations did not show a true global warming trend.

The claim was that many stations have registered warming because they are located in or near cities, and those cities have been growing - the urban heat island effect.

The Berkeley group found about 40,000 weather stations around the world whose output has been recorded and stored in digital form.

It developed a new way of analysing the data to plot the global temperature trend over land since 1800.

What came out was a graph remarkably similar to those produced by the world's three most important and established groups, whose work had been decried as unreliable and shoddy in climate sceptic circles.

Two of those three records are maintained in the US, by the National Oceanic and Atmospheric Administration (Noaa) and National Aeronautics and Space Administration (Nasa).

The third is a collaboration between the UK Met Office and UEA's Climatic Research Unit (CRU), from which the e-mails that formed the basis of the "Climategate" furore were hacked two years ago.

"Our biggest surprise was that the new results agreed so closely with the warming values published previously by other teams in the US and the UK," said Professor Muller.

"This confirms that these studies were done carefully and that potential biases identified by climate change sceptics did not seriously affect their conclusions."

Since the 1950s, the average temperature over land has increased by 1C, the group found.

They also report that although the urban heat island effect is real - which is well-established - it is not behind the warming registered by the majority of weather stations around the world.

They also showed that in the US, weather stations rated as "high quality" by Noaa showed the same warming trend as those rated as "low quality".
'Time for apology'

Professor Phil Jones, the CRU scientist who came in for the most personal criticism during "Climategate", was cautious about interpreting the Berkeley results because they have not been published in a peer-reviewed journal.

"I look forward to reading the finalised paper once it has been reviewed and published," he said.

"These initial findings are very encouraging, and echo our own results and our conclusion that the impact of urban heat islands on the overall global temperature is minimal."

The Berkeley team has chosen to release the findings initially on its own website.

They are asking for comments and feedback before preparing the manuscripts for formal scientific publication.

In part, this counters the accusation made during "Climategate" that climate scientists formed a tight clique who peer-reviewed each others' papers and made sure their own global warming narrative was the only one making it into print.

But for Richard Muller, this free circulation also marks a return to how science should be done.

"That is the way I practised science for decades; it was the way everyone practised it until some magazines - particularly Science and Nature - forbade it," he said.

"That was not a good change, and still many fields such as string theory practice the traditional method wholeheartedly."

This open "wiki" method of review is regularly employed in physics, the home field for seven of the 10 Berkeley team.

Bob Ward, policy and communications director for the Grantham Institute for Climate Change and the Environment in London, said the warming of the Earth's surface was unequivocal.

"So-called 'sceptics' should now drop their thoroughly discredited claims that the increase in global average temperature could be attributed to the impact of growing cities," he said.

"More broadly, this study also proves once again how false it was for 'sceptics' to allege that the e-mails hacked from UEA proved that the CRU land temperature record had been doctored.

"It is now time for an apology from all those, including US presidential hopeful Rick Perry, who have made false claims that the evidence for global warming has been faked by climate scientists."
Ocean currents

The Berkeley group does depart from the "orthodox" picture of climate science in its depiction of short-term variability in the global temperature.

The El Nino Southern Oscillation (ENSO) is generally thought to be the main reason for inter-annual warming or cooling.

But by the Berkeley team's analysis, the global temperature correlates more closely with the state of the Atlantic Multidecadal Oscillation (AMO) index - a measure of sea surface temperature in the north Atlantic.

There are theories suggesting that the AMO index is in turn driven by fluctuations in the north Atlantic current commonly called the Gulf Stream.

The team suggests it is worth investigating whether the long-term AMO cycles, which are thought to last 65-70 years, may play a part in the temperature rise, fall and rise again seen during the 20th Century.

But they emphasise that anthropogenic global warming (AGW) driven by greenhouse gas emissions is very much in their picture.

"Had we found no global warming, then that would have ruled out AGW," said Professor Muller.

"Had we found half as much, it would have suggested that prior estimates [of AGW] were too large; if we had found more warming, it would have raised the question of whether prior estimates were too low.

"But we didn't; we found that the prior rise was confirmed. That means that we do not directly affect prior estimates."

The team next plans to look at ocean temperatures, in order to construct a truly global dataset.

Global warming study finds no grounds for climate sceptics' concerns
Independent investigation of the key issues sceptics claim can skew global warming figures reports that they have no real effect
Ian Sample guardian.co.uk 20 Oct 11;

The world is getting warmer, countering the doubts of climate change sceptics about the validity of some of the scientific evidence, according to the most comprehensive independent review of historical temperature records to date.

Scientists at the University of California, Berkeley, found several key issues that sceptics claim can skew global warming figures had no meaningful effect.

The Berkeley Earth project compiled more than a billion temperature records dating back to the 1800s from 15 sources around the world and found that the average global land temperature has risen by around 1C since the mid-1950s.

This figure agrees with the estimate arrived at by major groups that maintain official records on the world's climate, including Nasa's Goddard Institute for Space Studies in New York, the US National Oceanic and Atmospheric Administration (Noaa), and the Met Office's Hadley Centre, with the University of East Anglia, in the UK.

"My hope is that this will win over those people who are properly sceptical," Richard Muller, a physicist and head of the project, said.

"Some people lump the properly sceptical in with the deniers and that makes it easy to dismiss them, because the deniers pay no attention to science. But there have been people out there who have raised legitimate issues."

Muller sought to cool the debate over climate change by creating the largest open database of temperature records, with the aim of producing a transparent and independent assessment of global warming.

The initial reluctance of government groups to release all their methods and data, and the fiasco over emails from the University of East Anglia's Climatic Research Unit in 2009, gave the project added impetus.

The team, which includes Saul Perlmutter, joint winner of this year's Nobel Prize in Physics for the discovery that the universe is expanding at an increasing rate, has submitted four papers to the journal Geophysical Research Letters that describe their work to date.

Going public with results before they are peer-reviewed is not standard practice, but Muller said the decision to circulate the papers before publication was part a long-standing academic tradition of sanity-checking results with colleagues.

"We will get much more feedback from making these papers public before publication," he said.

Climate sceptics have criticised official global warming figures on the grounds that many temperature stations are poor quality and that data are tweaked by hand.

However, the Berkeley study found that the so-called urban heat island effect, which makes cities warmer than surrounding rural areas, is locally large and real, but does not contribute significantly to average land temperature rises. This is because urban regions make up less than 1% of the Earth's land area. And while stations considered "poor" might be less accurate, they recorded the same average warming trend.

"We have looked at these issues in a straightforward, transparent way, and based on that, I would expect legitimate sceptics to feel their issues have been addressed," Muller said.

Nevertheless, one prominent US climate sceptic, Anthony Watts, claimed to have identified a "basic procedural error" concerning time periods used in the research, and urged the authors to revise the paper.

Jim Hansen, head of Nasa's Goddard Institute for Space Studies, said he had not read the research papers but was glad Muller was looking at the issue, describing him as "a top-notch physicist". "It should help inform those who have honest scepticism about global warming.

"Of course, presuming that he basically confirms what we have been reporting, the deniers will then decide that he is a crook or has some ulterior motive.

"As I have discussed in the past, the deniers, or contrarians, if you will, do not act as scientists, but rather as lawyers."

"As soon as they see evidence against their client (the fossil fuel industry and those people making money off business-as-usual), they trash that evidence and bring forth whatever tidbits they can find to confuse the judge and jury."

Peter Thorne at the Cooperative Institute for Climate and Satellites in North Carolina and chair of the International Surface Temperature Initiative, said: "This takes a very distinct approach to the problem and comes up with the same answer, and that builds confidence that pre-existing estimates are in the right ballpark. There is very substantial value in having multiple groups looking at the same problem in different ways.

"Openness and transparency is a must, particularly now with climate change being so politicised, but more to the point, with the huge socioeconomic decisions that rest on it."

Phil Jones, the director of the Climatic Research Unit at UEA who was at the centre of the Climategate incident, said: "I look forward to reading the finalised paper once it has been reviewed and published. These initial findings are very encouraging and echo our own results and our conclusion that the impact of urban heat islands on the overall global temperature is minimal."

The Berkeley Earth project has been attacked by some climate bloggers, who point out that one of the funders runs Koch Industries, a company Greenpeace called a "financial kingpin of climate science denial".

Muller points out the project is organised under the auspices of Novim, a Santa Barbara-based nonprofit organisation that uses science to find answers to the most pressing issues facing society and to publish them "without advocacy or agenda".

Other donors include the Fund for Innovative Climate and Energy Research (funded by Bill Gates), and the Department of Energy's Lawrence Berkeley Lab. The next phase of the project will focus on warming trends in the oceans.

Some scientists were critical of the project and Muller's decision to release the papers before they had been peer reviewed.

Peter Cox, professor of climate system dynamics at Exeter University said: "These studies seem to confirm the global warming estimated from the existing datasets, which is pleasing but not exactly a surprise to those of us who know how carefully the existing datasets are put together.

"It is surprising, however, that the authors believe that this news is so significant that they can't wait for peer review, especially when their conclusions aren't exactly revolutionary."