New Study Finds Much More Global Greening than Previously Estimated

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A new study paper on global greening by a team of Australian scientists—published in Global Change Biology with Vanessa Haverd of Australia’s Commonwealth Scientific and Industrial Research Organisation as lead author—demonstrates that previous estimates of carbon dioxide-induced global greening since 1900 are too small by a factor of two, that the observed greening in their biophysical model is extremely consistent with what is being measured by satellites, and that RCP 2.6 (the IPCC modeling scenario that assumes drastic cuts in greenhouse gas emissions) for this century would nonetheless create so much additional greening that it would be equivalent to 17 years of zero emissions from today’s level.

Ross McKitrick recently published a post on Judith Curry’s Climate Etc., in which he showed that observed emissions are below every scenario the United Nations has put out since 1990. That means the scenario in the new Australian study is indeed feasible.

I calculated the effect of the 17 years of zero-effective emissions dispersed through this century, and it reduces the warming—using the U.N.’s own overheated models—to 1.9˚C. In other words, our current emissions pathway will meet the Paris climate treaty’s goal of limiting the increase in the global mean temperature to 2˚C.