...and a bit under the weather, too

The second great religion of the doomsayers who may not be challenged is the concept of man-made climate change. I'm not a climate change denier, but I think that many of those who are rightly concerned about climate change do themselves no favours by overstating the case. In that sense, the climate change doomsayers are remarkably similar to the peak oil doomsayers.

We know that the earth’s climate is changing. Of course it is – as far as we can tell, there has never been a period when it hasn’t been. There have been lengthy periods of comparative climate stability, but climate has never been unchanging. So, whatever we do as humanity, we’ll have to deal with climate change at some level.

We also know that, since adopting an economy based largely on hydrocarbons, human activity has been pumping more carbon dioxide (as well as other gases) into the atmosphere, at a much greater rate than would happen without human activity. And that rate is increasing as more and more countries build up their industrial base.

We have very good reason to believe that changing the levels of carbon dioxide etc. in the atmosphere will impact on the global climate. Indeed, it would be very surprising if changing the composition of the atmosphere, even marginally, did not have an impact on climate, given the huge complexity of climate.

What we don’t actually ‘know’, however, is how much of a man-made impact on climate change there will be, nor what that impact will be. All of the predictions are based on complex mathematical models, and all of those models are based on assumptions (guesses to you and me) about some of the key variables. There's a good consensus around many of those guesses, and the people making them are seriously clever people; but a consensus of very clever people does not turn a guess into a fact. And there are some serious anomalies which some climate change alarmists are far too quick to dismiss.

I’m not arguing that we shouldn’t take climate change seriously. Significant climate change, whether man-made or natural, will have a massive impact on human society. And I’m certainly not arguing that we shouldn’t take urgent corrective action to reduce our impact on the atmosphere. Given how little we really know for certain about the impact of what we’re doing, it is madness to not only maintain our level of emissions but to be actually increasing them.

But it is equally a mistake to believe that reducing the impact of human activity to zero will avoid climate change - it won't. Earth's wobbles on its orbit, cyclic changes in the Sun and other factors will continue to have an impact on climate, whatever we do. We need to be preparing for climate change as well as trying to reduce or eliminate the man-made element – these are not either/or alternatives.