Saturday, February 14, 2009
David Bellamy on Global Warming
David Bellamy does global warming scepticism on BBC Wear : Hi s main point is "strawberries in December, frog spawn in February – not 2007 but 1868 and no one blamed global warming then. I have asked the global warmers how to explain facts like that and they always don't give me an answer. So I am a sceptic"
David runs the now-standard sceptic line: Yes, climate change is happening, but it is all due to natural variation from the sun. Digging up fossil carbon stores and putting them into the atmosphere as carbon dioxide has nothing to do with it.
He asks for an explanation of what happened in 1868. I have put up the IPCC graph of surface temperature anomalies above. As you see, there are fairly regular variations (with a period of about 15 years) of the red line, the 5 year average, and one of these occurred around 1870. That's it, David. That's the fact. 1868 was a warm year. Just as it is a fact that we are on a downward part of a variation since 2000 - which is seized on by denialists as "proof" that the earth is cooling.
Real Atmosphere science has to take in the widest view, take in all the factors. Surface temperatures are the result of many factors, which include green house gases, El Nino, La Nina, proximity to the sun, solar irradiance (to a very small degree), and albedo. We are certainly nowhere near a conclusive picture. But we have enough evidence, and enough consensus within the scientific community, to take action in decarbonising our economy, and enhancing natural carbon sinks to rebalance the earth's greenhouse effect.
There is a concise summary of the debate here.