July 2012
A scientific study set up to address climate change sceptics' concerns with respect to human-induced global warming has concluded that the Earth's land has warmed by 1.5C over the past 250 years and that "humans are almost entirely the cause".
The project at the University of California, Berkeley, received $150,000 from the Charles G Koch Charitable Foundation, set up by the billionaire US coal magnate and principal backer of the climate-sceptic Heartland Institute thinktank. The Fund for Innovative Climate and Energy Research, created by Bill Gates, contributed another $100,000.
The team of scientists merged I4.4m land temperature observations from 44,455 sites dating back to 1753. Previous data sets created by NASA, the US National Oceanic and Atmospheric Administration, the Met Office and the University of East Anglia's climate research unit only went back to the mid-1800s and used only a fifth as many weather station records.
Responding to a key criticism made by climate sceptics in the past, the temperature data from various sources was not homogenised by hand, but was instead "completely automated to reduce human bias". The Best team report that this deeper analysis has produced findings which closely match the previous temperature reconstructions, "but with reduced uncertainty". In other words, the deeper analysis has strengthened previous findings.
Prof Richard Muller, a physicist and climate change sceptic who founded the Berkeley Earth Surface Temperature (Best) project, expresses his surprise at the findings. "We were not expecting this, but as scientists, it is our duty to let the evidence change our minds." Muller now describes himself a "converted sceptic".
Muller gave his view in the New York Times: "Our results show that the average temperature of the Earth's land has risen by 2.5F over the past 250 years, including an increase of 1.5 degrees over the most recent 50 years. Moreover, it appears likely that essentially all of this increase results from the human emission of greenhouse gases."
In October 2011, the Best team published results that showed a rise of 1C in the average global land temperature since the mid-1950s. However, the team did not look for the causes of this warming. The latest data analysis not only goes much further back in time but also seeks to identify the most likely cause of the rise by plotting the upward temperature curve against suspected "forcings".
The team analysed the two theories most popular amongst climate change sceptics – solar activity and volcanic eruptions – and found their influence to be negligible and non-existent. The warming impact of solar activity was examined but the team found that the contribution of the sun to warming over the past 250 years has been "consistent with zero". Volcanic eruptions, a theory promoted by Ian Plimer, the favourite ‘sceptic’ of certain newspapers, were found to have caused short dips in the temperature rise between 1750 and 1850, but "only weak analogues" in the 20th century.
Geologist Ian Plimer has described AGW as "a load of hot air underpinned by fraud". Leo McKinstry in the Daily Express refers to ‘lies, damned lies and global warming’. Referring to climate scientists, McKinstry makes this claim: ‘Their rhetoric is as bogus as the science they use.’ Now that is a testable claim. There are people who deny scientific reason as such, and there is no arguing with them. Truth is whatever they want to believe it to be. But the claim that climate science is ‘bogus’ science implies that there is such a thing as ‘genuine’ science. In using words like ‘lies’ and ‘fraud’, it behooves these journalists to produce the evidence that backs alternative explanations. They don’t have it. The theories of the scientists they favour, like Ian Plimer, have been round the block more times than my postman. They have been tested and found wanting. Every time a journalist or a politician weighs into this area – Peter Hitchens, Peter Sissons, Anne Widdecombe, Neil Hamilton, Melanie Phillips, Johnny Ball - then he or she should be told to put up the evidence and the explanation or shut up.
I know the words ‘fish’ ‘shooting’ and ‘barrel’ come to mind, but it is worth singling one of these characters out for the way that they typify a certain approach taken to the science of climate change in the mass media. In the Daily Express of January 16 2010, Richard Madeley takes a typically cheap shot against the Met Office. ‘I thought the Met Office boasted the finest computers and best brains in the business. They have satellite technology their predecessors couldn't have dreamt of yet they can't give an accurate forecast for the next 24 hours when it counts.’ (Met Office got it wrong once more). The weather is irreducibly complex and therefore unpredictable and that’s all there is to it. But it is clear that there is a concerted attempt by deniers to conflate meteorology and climatology in order to undermine the case for man-made global heating. The science on climate change is solid. Climate change deniers haven’t been able to dent the case for human-made global heating in the slightest. So they resort to the unpredictability of the weather, the inability to give accurate forecasts, and proceed to cast aspersions on the science behind it. ‘One wonders about the underlying science behind their methods. Controversial independent forecaster Piers Corbyn claims conventional meteorologists use the wrong data to form their predictions, particularly for long-range forecasts. He says solar activity is not paid nearly enough attention and is a reliable indicator of which way the wind will blow.’
Solar activity has been paid more than enough attention. The findings are these, that the sun may have contributed to heating in the first part of the 20th century but has not caused the rapid heating we have experienced since the late 1970s. In a recent research project, Professor Muller and his Best team analysed solar activity and found its influence to be ‘negligible’. If Corbyn can show otherwise, then he should subject his evidence to proper scientific examination, not laypersons in the media. That’s how minds are changed in science – not by political pressure and persuasion, but by good, sound evidence.
The BEST team’s findings go further and are much stronger than the latest report published by the Intergovernmental Panel on Climate Change. Slammed as a political body dabbling in pseudo-science, it seems that the IPCC does indeed suffer from an institutional bias, leading it to dilute hard truths and diminish the scale of the problem of global warming.
Professor Muller was once a climate change sceptic but, like any proper scientist, has been led by the evidence. "Much to my surprise, by far the best match came to the record of atmospheric carbon dioxide, measured from atmospheric samples and air trapped in polar ice," Muller argues. "While this doesn't prove that global warming is caused by human greenhouse gases, it is currently the best explanation we have found, and sets the bar for alternative explanations."
Prof Michael Mann is the Peon State palaeo-climatologist who has suffered hostile criticism from climate change deniers for his "hockey stick" graph, which purported to show a rapid rise in temperatures during the 20th century. Mann welcomes the BEST research as confirmation of his own findings: "I applaud Muller and his colleagues for acting as any good scientists would, following where their analyses led them, without regard for the possible political repercussions."
That is precisely what we should all be doing, following the evidence regardless of the politics. In politics, power, influence, persuasion and influence counts most. The rich and powerful tend to win by some variety of force and fraud. In science, it’s the hard research, facts and evidence that counts.