New research from Stephen Schwartz of Brookhaven National Lab concludes that the Earth’s climate is only about one-third as sensitive to carbon dioxide as the IPCC assumes. Schwartz’s study is “in press” at the Journal of Geophysical Research and you can download a preprint of the study here.
According to Schwartz’s results, which are based on the empirical relationship between trends in surface temperature and ocean heat content, doubling the CO2 concentration in the atmosphere would result in a 1.1oC increase in average temperature (0.1–2.1oC, two standard deviation uncertainty range). Schwartz’s result is 63% lower than the IPCC’s estimate of 3oC for a doubling of CO2 (2.0–4.5oC, 2SD range).
A couple of other interesting implications of Schwartz’s results:
- Aerosols have a relatively small effect on temperature. A doubling of CO2 has an estimated climate “forcing” of 2.7 watts per square centimeter (W/cm2). In contrast, actual aerosol concentrations during the 20th Century had a forcing of -0.3 W/cm2 with a large uncertainty range that could mean either net cooling or net warming from aerosols.
- The response time, or “time constant”, of the climate to greenhouse gas forcing is relatively small—only five years. In other words, there’s hardly any additional warming “in the pipeline” from previous greenhouse gas emissions. This is in contrast to the IPCC, which predicts that the Earth’s average temperature will rise an additional 0.6oC during the 21st Century even if greenhouse gas concentrations stopped increasing.
Stephen Schwartz is a pretty mainstream climate scientist. Yet along with dozens of other studies in the scientific literature, his new study belies Al Gore’s claim that there is no legitimate scholarly alternative to climate catastrophism.
Indeed, if Schwartz’s results are correct, that alone would be enough to overturn in one fell swoop the IPCC’s scientific “consensus”, the environmentalists’ climate hysteria, and the political pretext for the energy-restriction policies that have become so popular with the world’s environmental regulators, elected officials, and corporations. The question is, will anyone in the mainstream media notice?