Climate change - excuse my ignorance

I have been getting so little response to my posts just recently that I thought I would write one that is bound to elicit a loud response (while I will also be pondering whether it is time to hang up my blogging boots).

The backlash against the stupid and unethical behaviour of climate scientists at East Anglia University, the shot across David Cameron’s green bows by former shadow cabinet member David Davis in The Telegraph this morning, and the Daily Express’ championing of highly controversial climate change sceptic Ian Plimer are all signs of a growing tide.

I had already begun to notice that among Conservative friends of mine the theory of anthropogenic climate change now ranks with the European Union as a subject that merely has to be mentioned to elicit a hostile reaction. Although the Tory front bench remains strongly committed to the need for a concerted action on climate change, at the level of party activists and political opinion formers a clear left right gap is emerging. At the recent Conservative conference the loudest applause on the fringe went to the sceptical views eloquently expressed by Lord Lawson.

The problem with knowing how to respond is that 99% of us have neither the time nor the expertise to make our decision based purely on the science. People with strong opinions throw around their favourite statistics claiming their views are scientifically based but this usually tells you much more about who these people are inclined to trust than what the facts say.

Maybe it would be better for the debate if more of us owned up to how much we rely on hunch, trust and selecting certain facts as the ones we intuitively feel are the most important. At the risk of sounding naive and feeble minded, let me try to be honest about what drives my views.

My starting point is two facts which I don’t think are disputed: first that CO2 is a greenhouse gas and second that human activity is leading to much more of it being pumped into the atmosphere, with much more to come if we don’t find alternative ways of generating and using energy.  Furthermore I find it hard to see why the overwhelming majority of scientists – from a whole variety of perspectives and disciplines – would sign up to the climate change thesis if there weren’t very good reasons to do so.

There seem to be two questions that cause the biggest quasi-scientific controversy. First, has there been major climate change in the past unrelated to human emissions and if so does this invalidate the IPCC thesis? Second, what is actually happening to the climate now and how can we predict what will happen in the future on the basis of assumptions about the link between human-caused emissions and temperatures.

On the first of these I think we should beware the argument that just because there was an unexplained correlation in the past, or even that a correlation doesn’t work perfectly, that it doesn’t exist. The fact that some people get lung cancer having never smoked doesn’t disprove the link. Equally, while a football team may have had an inexplicable bad run in the past doesn’t mean its present bad run can’t rightly be put at the door of its manager.

On the issues of climate trends and scenarios, I accept the precautionary principle (whilst not believing this is a principle that should be applied in all situations of risk). There are enough reasons to think rising emissions could drive accelerating warming to conclude it is not an experiment we should conduct if we can avoid it.

Finally, I believe that we can adjust to a low carbon economy without having to massively hamper other goals such as global economic development; not because we are all happy to become vegetarians and live in yurts but because a combination of changes in consumption, clever regulation and technological innovation can do the trick, and at the same time help us deal with the problem of the finite supply of carbon based energy.

As I read this back I know it lacks the certainty and authority with which so many non- scientists speak on this subject. I am discussing this issue on the Moral Maze tonight and I know I will probably – and not for the first time -  be the most wishy- washy voice. But given that the overwhelming majority of us who will be affected by the decision on climate policy maybe it is useful to explore basic arguments at a level accessible to a busy layperson.