Global warming 'confirmed' by independent study

Weather station at airport Weather stations are giving a true picture of global warming, the group found

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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.

Saul Perlmutter The group includes physicist Saul Perlmutter, a Nobel Prize winner this 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.

Start Quote

Our biggest surprise was that the new results agreed so closely with the warming values published previously”

End Quote Richard Muller Berkeley group founder

"I was deeply concerned that the group [at UEA] had concealed discordant data," Prof Muller told BBC News.

"Science is best done when the problems with the analysis are candidly shared."

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.

graph The Berkeley group's record of global land temperature mirrors existing ones closely

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 Prof 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'

Prof 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.

Professor Phil Jones The findings so far provide validation for Phil Jones, targeted during the "Climategate" affair

"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 other's 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 Research 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 Prof 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.

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  • rate this

    Comment number 17.

    @ Charlie,

    Quite right - we could go to an Eocene climate (which we will if we burn all the fossil fuels on Earth) and the antis would still be up to the same antics. The best thing the public and policymakers alike can do is move on along, ignoring them!

    @ Episkopian,

    So you will not accept AGW until EVERYONE does? How about the Moon landings while we're at it???

    Cheers - John

  • rate this

    Comment number 16.

    So, the team hired by the Koch brothers concludes that UEA is conservative in its science, since UEA's temperature graph is higher in the 1800s and lower in modern times than theirs. Yet again the Climate scientists are vindicated and we need to take global warming seriously. For example, we could start by prohibiting (extremely carbon-intensive) Shale Oil extraction in the UK :-) !

  • rate this

    Comment number 15.

    Perhaps next time use a picture of a weather station that isn't parked behind a jumbo jet. Can you imagine why that particular station shows its hotter at that site than 100 years ago?

    What I find amusing about 'climate change' is that it implies the earths climate should be constant. Hardly. We cycle from hot spell to ice age and back again. In 1948 the North Sea froze off Skegness.

  • rate this

    Comment number 14.

    Well said #1.

  • rate this

    Comment number 13.

    I'm tired off all of this global warming rubbish. The earth is coming out of the last ice age still. It's clearly going to warm up. Stop moaning and get on with it. Even if the ice caps melt and flood the planet and wipe everything out its not much of a big deal for the planet. It was around a long time before we were, and I bet it will be around a long time once we've gone.

  • rate this

    Comment number 12.

    I'm a global warming sceptic but I do agree with one conclusion.

    The climate changes.

    That's the one bit we all have to agree on, no matter how dysfunctional our idiocy is.

    As for the rest of it...well no one really knows.
    All we do know is...the climate changes.

  • rate this

    Comment number 11.

    The usual "la la la I'm not listening" response from the sceptics. Their straw-clutching will become ever more desperate and idiotic henceforth.

  • rate this

    Comment number 10.

    "But they emphasise that AGW driven by greenhouse gas emissions is very much in their picture."
    So they admit that they don't know whether GW is caused by human activity. Surely a much better argument for reducing our consumption is that we need to leave some resources for our kids.

  • rate this

    Comment number 9.

    Some people will dismiss this data. Either because they have a Political agenda or possibly because they are dysfunctional idiots who can't read a graph, or listen to the opinion of someone with scientific qualifications who actually studies climate data.

  • rate this

    Comment number 8.

    I believe that the climate is changing, as it has been since there has been a climate. Is it being accelerated by manmade emissions and even if it is, would the warming just happen more slowly without us?

    We have had much colder and much warmer periods before possible human interference came along and this graph only goes back to 1800, a minute period in the history of our planet.

  • rate this

    Comment number 7.

    Now that all the data is out in the open, I look forward to reading climate sceptics critical review of it. Should be interesting. Though it's likely they'll won't take the time to look.

  • rate this

    Comment number 6.

    Eh ,the world used to be , more or less , a giant snowball floating in space , at one time , it has not been so for some considerable time now , thank goodness and it took a team of noted "experts" how long to conclude that the planet is warming ? ......... Is it just me ?

    I wonder what taxes they want to introduce or increase now ?

  • rate this

    Comment number 5.

    While this shows an effect that few doubted, it goes nowhere to identify the cause.

    Some hypoyhesize that it is dwn to human activity, others that there is another factor, such as the cycles of the Sun.

    We need more objective scientific research into all possible causes, but until that is proven one way or another it is prudent to continue or escallate our reductions in Carbon emissions.

  • rate this

    Comment number 4.

    I will not pretend to understand global warming, but by looking out of my window it is certainly not warm here in Yorkshire, there was ice on my car plus this summer has been a wash out again.. Also I do not believe that it is man made. I think it is more likely to be caused by the big orangy yellow thing in the sky called the Sun.

  • rate this

    Comment number 3.

    Well, surprise surprise.

  • rate this

    Comment number 2.

    It is acknowledged by almost all relevant scientific bodies that the earth is getting warmer but that comes under the heading of Climate Change. I seriously doubt that man is having any really significant effect on climate. Until there is universal acceptance that mankind contributes to global warming I will continue to believe that this view is derived from biased analysis or misinterpreted data.

  • rate this

    Comment number 1.

    Climate-change critics don't believe because they don't want to - I doubt another report free from bias and authored by distinguished scientists will convince them.


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