Global warming less than we thoughtRichard Treadgold | May 20, 2013
Don’t have time to look closely, but here’s a taste of good news.
*abridged* New research from Oxford University shows the rate of global warming has been lower over the past decade than it was previously.
The paper, “Energy budget constraints on climate response”, to be published online by Nature Geoscience, shows the estimated average climate sensitivity – or how much the globe will warm if carbon dioxide concentrations are doubled – is almost the same as the estimates based on data up to the year 2000.
The study, which uses data from the past decade, also shows the most extreme rates of warming simulated by climate models over 50- to 100-year timescales are looking less likely.
The study used the most up-to-date information available to the AR5 from the IPCC, which is due to be finalised in September.
Victoria University climate scientist James Renwick said there was always a range of uncertainty and it had been hard to rule out the possibility that the climate sensitivity might be very large.
“Using the latest data shows that those very high sensitivities look much less likely, so we’ve been able to tighten the range of uncertainty, especially at the high end,” he said.
“We have much more comprehensive and reliable data on ocean heat content these days, and there haven’t been many large volcanic eruptions lately to obscure things, so that has allowed a better estimate of the range of climate sensitivity.”