Have you ever wondered where the 2⁰C number comes from? Does it sound like the Y2K scare all over again? Well, let me tell you, because I have something to do with provoking its original publication.
In 1995, I published an article in Eos, the journal that goes to every member of the American Geophysical Union, a professional society of which I am a life-member and an elected Fellow. I claimed there that we couldn’t see any evidence for a significant human contribution to global warming. Naturally, this provoked some immediate responses — which I commented on in turn.
One response came from two Swedish scientists, Henning Rodhe and Christian Azar of Stockholm University. This was the first time I saw this magic 2⁰C value. Of course, they gave a reference for this number, which turned out to be a publication in the Swedish journal Tellus — by the same authors. In other words, it was a self-reference — or a circular argument if you prefer. It may even have been self-refereed; I don’t know. Anyway, there is nothing to indicate that anything drastic will happen at the 2⁰C limit. None of the climate models suggest any particular disaster; there will be no runaway warming; and climate warming will not become irreversible.