Monday, January 28, 2013

Climate change: Worse than Stern thought

Back in 2006 the UK government released the Stern Review, an in-depth look at the effects of climate change on the global economy. Stern concluded that climate change would impose immense costs, though drought, famine, and consequent impacts on human health and the environment, and that there was a strong economic case for action to counter it. Now, he says things are turning out far worse than he expected and that he didn't go far enough:

Lord Stern, author of the government-commissioned review on climate change that became the reference work for politicians and green campaigners, now says he underestimated the risks, and should have been more "blunt" about the threat posed to the economy by rising temperatures.

In an interview at the World Economic Forum in Davos, Stern, who is now a crossbench peer, said: "Looking back, I underestimated the risks. The planet and the atmosphere seem to be absorbing less carbon than we expected, and emissions are rising pretty strongly. Some of the effects are coming through more quickly than we thought then."

The Stern review, published in 2006, pointed to a 75% chance that global temperatures would rise by between two and three degrees above the long-term average; he now believes we are "on track for something like four ". Had he known the way the situation would evolve, he says, "I think I would have been a bit more blunt. I would have been much more strong about the risks of a four- or five-degree rise."

According to the IPCC's Fourth Assessment Report, four degrees means widespread widespread water stress and a significant decrease in crop yields. In English, that's drought and famine. In addition, we'll get more deaths from extreme weather events such as floods and heat-waves, the spread of tropical diseases, and a worldwide mass-extinction. Even if you don't give a shit about impacts on the non-human environment, the impacts on people will be enormous and negative.

Stern estimated the cost of two to three degrees of temperature rise to be between 5% and 20% of global GDP, and the cost of acting to be about 1%. Now we're looking at higher costs, the economic case for acting looks even stronger.

...And meanwhile, our government sits there twiddling its thumbs and refusing to do anything because it might cost their pet farmers and truckers money. Which means they'll just end up paying more in drought relief and health costs later.

(Also on climate change: a well-argued piece from Cass Sunstein on why the US should act unilaterally on climate change. The short version? It would break the negotiation deadlock, while delivering immediate and tangible economic benefits. Unmentioned is that this would come at the cost of existing economic interests in the oil and coal industries. The question is whether the US will cut its own throat and burn the planet just so a clique of rich old guys can keep their money...)