Comparing past climate change to recent global warming
What the science says...
It warmed just as fast in 1860-1880 and 1910-1940
“In fact, the rate of warming from 1975-2001, at 0.16 °C per decade, was the fastest rate to be sustained for more than a decade in the 160-year record, but exactly the same rate occurred from 1860-1880 and again from 1910-1940, when we could not possibly have had anything to do with it.” (Christopher Monckton)Let’s have a look at some warming rates of the periods of interest from several different temperature records:
Table 1: Rate of warming for given indices in °C/century.
First we can conclude that Monckton's statement that 1975-2001 was the fastest warming rate for longer than a decade is absolutely wrong as a much higher rate is demonstrated for 1975-2005 in row 5. Secondly, to compare the three periods in Table 2, the only index which covers that period is Hadley, making his 1.6°C per century number wrong for 1975-2001 as it is actually much higher at 1.78°C per century.
Based upon the evidence presented here, he cannot support his statement that 1860-1880 had a similar warming rate as it was demonstratively lower than the 1975-2001 warming rate and nearly half the 1975-2005 rate. Finally, regarding the 1910 to 1940 warm period, evidence presented here suggests that only 1 out of the 4 major indices indicates a rate of warming within 0.25°C per century and none within 0.2°C. His claim that the rates are similar is dubious at best.
Last updated on 31 January 2011 by robert way.
Climate Myth...