Real prediction vindicated

Real Climate has been running hot lately with:

a. a lengthy guest post by "Tamino" reviewing a book on the hockey stick controversy, and explaining in great detail why McIntyre is wrong. In comments, there is a full blown fisking of the Judith Curry's quasi-defence of the book and McIntyre, and she does not come out of it well.

b. a post noting the surprisingly accurate predictions of global warming from the mid 1970's by Wally Broecker, who even coined the term "global warming". The article notes:

To those who even today claim that global warming is not predictable, the anniversary of Broecker’s paper is a reminder that global warming was actually predicted before it became evident in the global temperature records over a decade later (when Jim Hansen in 1988 famously stated that “global warming is here”).

He wasn't the first to predict warming from CO2, though:

Broecker was not the first to predict CO₂-induced warming. In 1965, an expert report to US President Lyndon B. Johnson had warned: “By the year 2000, the increase in carbon dioxide will be close to 25%. This may be sufficient to produce measurable and perhaps marked changes in climate.” And in 1972, a more specific prediction similar to Broecker’s was published by the eminent atmospheric scientist J.S. Sawyer in Nature (for a history in a nutshell, see my newspaper column here).

The innovation of Broecker’s article – apart from introducing the term “global warming” – was in combining estimates of CO₂ warming with natural variability. His main thesis was that a natural climatic cooling

has, over the last three decades, more than compensated for the warming effect produced by the CO₂ [....] The present natural cooling will, however, bottom out during the next decade or so. Once this happens, the CO₂ effect will tend to become a significant factor and by the first decade of the next century we may experience global temperatures warmer than any in the last 1000 years.

The latter turned out to be correct.

For all the skeptics who thought it was only global cooling being considered in the mid 70's, this is well worth reading.