The Worst Case of Mass Hysteria the World Has Known.

James Delingpole is an author and journalist with Telegraph.co.uk. He is the author of the following blog. His website is www.jamesdelingpole.com.

"How can we possibly stop the environmental and energy policy of our government being based on what US meteorologist Dr Roy Spencer calls “the worst case of mass hysteria the world has known.”?

Dr Spencer, formerly senior scientist for climate studies at NASA, now leads the US science team for the Advanced Microwave Scanning Radiometer for EOS (AMSRE) on NASA’s Aqua satellite.

He co-developed the original satellite method for precise monitoring of global temperatures from Earth-orbiting satellites. He’s just the kind of egghead the IPCC claims to represent when it tells us the world is getting dangerously warmer, it’s man’s fault – the result of CO2 emissions – and it must be urgently addressed.

Except Dr Spencer doesn’t agree with any of that. He thinks it’s all nonsense, based on a very elementary error he describes in his new book The Great Global Warming Blunder. I summarise his arguments in this article.

Climate change, he shows, is an almost entirely natural process on which human influence is negligible.

Of course, sceptics have been making this point for years, arguing that the quantities of carbon dioxide (CO2) produced by man are so tiny that even if they were to double there would still be no dangerous Anthropogenic Global Warming (AGW).

What they have been unable to answer convincingly until now, though, is the alarmists’ counterargument that CO2 emissions are exaggerated by “positive feedbacks”.

One type of positive feedback often cited by alarmists is cloud cover. When CO2 causes the world to warm, they argue, it reduces the number of clouds. Clouds are what help protect our planet from the burning heat of the sun, by reflecting solar radiation.

So even if the effect on climate of CO2 is relatively small, the potential knock-on effect is vast. This is why the predictions of temperature rises made by the Intergovernmental Panel On Climate Change (IPCC) assessment reports are so large and terrifying.

But according to Spencer, these alarmists have got completely the wrong end of the stick. The mistake they have made is to confuse cause with effect. It’s not man-made global warming that is causing cloud cover to grow thinner, leading to a spiral of ever-rising temperatures. Rather, it’s natural variations in cloud cover that are helping to cause global warming."