Monday, April 29, 2013

The slow roast

Left on the cutting room floor at the Sydney Morning Herald...

With CO2 about to breach the 400ppm barrier and likely to continue rising over the coming decades (Greenhouse gas levels highest in 3M years, 29/4) I'm sure readers will be heartened to learn that recent estimates of the climate's sensitivity to this greenhouse gas are lower than previously thought (see link below*). Based on current best estimates (1.6 degrees C per doubling) we are likely to experience further warming of about 0.8 degrees C by the end of the century. The lower climate sensitivity goes some way to explain why the IPCC's climate models have failed to forecast the current hiatus in global temperatures since 1998 despite massively increasing CO2 emissions.
This slow roast hardly represents what former PM Rudd called "the greatest moral, economic and environmental challenge of our generation".  It also pulls the rug from under the feet of ardent alarmists like Clive Hamilton who has moved from calls to suspend democracy to save the planet, to supporting civil disobedience against the coal industry (whatever that entails). Ironically, an industry that through its taxes helps fund Hamilton's generous salary.

*See http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-12-00473.1

Lewis N., 2013. An objective Bayesian, improved approach for applying
optimal fingerprint techniques to estimate climate sensitivity.
Journal of Climate 2013 ; e-View
doi: http://dx.doi.org/10.1175/JCLI-D-12-00473.1