Global Warming 'Pause' Since 1998 Reflects Natural Fluctuation

Statistical analysis of average global temperatures between 1998 and 2013 shows that the slowdown in global warming during this period is consistent with natural variations in temperature, according to research by McGill University physics professor Shaun Lovejoy.

Lovejoy's new study concludes that there has been a natural cooling fluctuation of about 0.28 to 0.37 degrees Celsius since 1998 -- a pattern that is in line with variations that occur historically every 20 to 50 years, according to the analysis.  "We find many examples of these variations in pre-industrial temperature reconstructions" based on proxies such as tree rings, ice cores, and lake sediment, Lovejoy says.  "Being based on climate records, this approach avoids any biases that might affect the sophisticated computer models that are commonly used for understanding global warming."

What's more, the cooling effect observed between 1998 and 2013 "exactly follows a slightly larger pre-pause warming event, from 1992 to 1998," so that the natural cooling during the "pause" is no more than a return to the longer term natural variability, Lovejoy concludes.  "The pause thus has a convincing statistical explanation."

Global Warming 'Pause' Since 1998 Reflects Natural Fluctuation