Matt Ridley responds:

I discovered something my informants had failed to disclose – that even fast rising levels of carbon dioxide could not on their own generate “several degrees” of warming in a century: for that to happen requires amplification by water vapour. All the models assumed this amplification, but the evidence for it began to look more and more threadbare. So by 1993, six years after the piece just quoted, I no longer thought that 2-10 feet of sea level rise was likely and I no longer thought that several degrees of warming were likely. Instead, I wrote – in a single throwaway sentence in a long piece about eco-scares generally – that

“Global warming, too, has shot its bolt, now that the scientific consensus has settled down on about a degree of temperature increase over a century-that is, little more than has taken place in the past century.”

This was published in a book the Economist put out each year called (in this case) “The world in 1994”. The main prediction of the essay, by the way, was that genetic engineering was the next big eco-scare. I was right, if a few years early, and I did not spot that tomatoes, rather than dolphins, would be the species that touched the heart strings and purse strings of the green movement. I’ll append the essay at the end of this blog post for those that are interested.

I am even prouder of that sentence. At the time such a “lukewarm” view was unfashionable among activists, though not yet among scientists – and you were allowed to say things like that without being treated like a holocaust denier. But it’s not far from what I think now. Since the modal climate sensitivity in all the best studies is now settling down at a bit over 1.5 degC, and since the effect of aerosols, black carbon, ocean heat uptake etc are now all better understood and provide fewer and fewer excuses for high sensitivity models to disagree with data, for me to have come up with “about a degree” two whole decades ago, in a single sentence in an essay on other topics, seems quite surprising. Climate change was not my main interest then: I was writing a book about the evolution of sex having left the Economist to be my own boss.

Indeed, if you take a look at the graph below, you will see that over 34 years, there has been about 0.36 degrees of warming on a rolling average using data from five different sources: or on track for 1.08degC in a century, give or take. About a degree?

…Now look, fellers, you do this kind of thing for a living. I’m just a self-employed writer with no back-up team, no government grants, no taxpayer salary, no computer simulations, and absolutely no pretensions to being Nostradamus about anything. But it strikes me I did a far better job of predicting the climate back in 1993 than any of you! How could that be?

Anyway, the whole episode was depressing in two ways.

First, it’s a little sad that a lecturer in computer graphics took the trouble to look up a sentence a freelance journalist wrote 20 years ago in a piece about something else and falsely claimed it was already “wrong” when it isn’t, and would hardly matter if it was. Does he not have anything better to do?

Second, it’s also a little sad to read just how little has changed in the climate debate since then. If I could travel back in time and tell my 34-year-old self in 1993 that I would be roughly right to take a “lukewarm” view about global warming, but that in the meantime the world would ignore me and would instead spend hundreds of billions of dollars on ways to prevent the poor getting rich with cheap electricity, on destroying rain forests to grow biofuels, on spoiling landscapes with windmills to provide less than half a percent of the world’s energy, and on annual conferences for tens of thousands of pampered activists, then surely my younger self would gape in disbelief.

Well, in order to get a government salary, you have to come up with the politically correct, if scientifically incorrect answer, as (e.g.) Jim Hansen does. Speaking of which, even he’s starting to climb down from his more extravagant hysteria.