Lomborg on the IPCC and megaphone journalism

These days I ration myself to a quick daily glance at the Guardian’s Comment is Free bl*g. Anything more than 90 seconds or so gives me a headache, and is in any case a completely unproductive use of my time.

So, when I scan through the front page and see articles on global warming, I tend to groan if the byline is “George Monbiot”, “Tony Juniper” or “Jeremy Leggett”. If it is, one can be almost guaranteed a thousand words of hot air, including a reference to how hot recent summers have been. A little science is a dangerous thing.

Today, however, it’s the turn of Bjørn Lomborg: a political scientist and controversialist who is always good for a lively debate.

I am a critic of Lomborg when it comes to his interpretation of climate science, but at the same time a supporter against those who claim he is a climate change denying charlatan. Lomborg is neither a climate change denier nor a charlatan. He is, on the other hand, a not very good interpreter of scientific data, with a not particularly deep understanding of experimental statistics in the physical sciences.

In today’s CiF article, Lomborg comes straight to the point:

“The IPCC has produced a good report [*] – an attempt to summarise what the world’s scientists know about global warming. Unlike the Bush administration, caught downplaying the science, the IPCC squarely tells us that mankind is largely responsible for the planet’s recent warming. And, unlike Al Gore, who has travelled the world warning that our cities might soon be under the oceans, it refrains from scaremongering.”

Al Gore‘s Oscar-nominated documentary “An Inconvenient Truth” is little more than a horror movie designed to scare the bejeezus out of the public, and resurrect a failing political career. And the less said about the Hollywood blockbuster “The Day After Tomorrow” – now remaindered in a video store near you – the better.

Gore’s focus on a possible seven metre sea level rise and the shutting down of the Gulf Stream is not complete fantasy. It is a possibility if positive feedback mechanisms kick in and polar ice sheets either disappear or reduce dramatically within decades, but the calculable probability of this happening is extremely low.

By concentrating on this extreme scenario, however, one can easily overlook the still serious consequences for human communities and local ecosystems from a much lower (sub-metre) sea level rise, and it diverts the debate away from how we can mitigate the effects of inevitable climate change. I’m therefore glad to see Lomborg condemning what he refers to as “megaphone journalism”.

But Lomborg is wrong to play up the IPCC’s lowering of the most likely sea level rise. True, the upper bound has been lowered from 88 to 59 cm, but the lower bound has at the same time risen from 9 to 18 cm. The reduction is due to the new report not including the results from ice dynamics models. And the reason why ice dynamics models have been excluded is that there is a great deal of uncertainty in their output. The situation could actually be more serious than previously thought.

Lomborg is also wrong to criticise senior IPCC personnel for calling on governments to take “more serious action”. They are merely reflecting majority opinion within the climate science community, which is naturally concerned by the data and model results they pore over on a daily basis. The scientists’ outspokenness may in one sense be political, but this is a political and moral responsibility they cannot evade.

* Note that this is not the full IPCC report, but rather a 20-page summary for policymakers (and, of course, journalists). The full report will not be released until later in the year.