It is a testament to the power of money that British economist Nicholas Stern's report on the economic effect of climate change should have swung the argument for drastic action -- even before anyone had finished reading it. He appears to have demonstrated, as many suspected, that it would cost much less to prevent runaway climate change than to seek to live with it.
Useful as this finding is, I hope it doesn't mean that the debate will now concentrate on money. The principal costs of climate change will be measured in lives, not dollars. As Stern reminded us on Monday, there would be a moral imperative to seek to prevent deaths on a massive scale even if the economic case did not stack up.
But at least almost everyone now agrees that we must act, even if they do not agree on the speed that actions should be taken with. If we're to have a high chance of preventing global temperatures from rising by 2oC above preindustrial levels, we need, in the wealthier nations, a 90 percent reduction in greenhouse gas emissions by 2030. The greater part of the reduction must be made immediately.
To see why, picture two graphs with time on the horizontal axis and the rate of emissions plotted vertically. On one graph the line falls like a ski jump: a steep drop followed by a shallow tail. On the other it falls like the trajectory of a bullet. The area under each line represents the total volume of greenhouse gases produced in that period. They fall to the same point by the same date, but far more gases have been produced in the second case, making runaway climate change more likely.
So how do we do accomplish a 90 percent reduction without bringing civilization crashing down?
I would like to propose a plan for drastic but affordable action that the British government, to name but one, could take. It goes much further than the proposals discussed by British Prime Minister Tony Blair on Monday, for the reason that this is what the science demands.
First, set a target for reducing greenhouse-gas emissions based on the latest science.
The UK government is using outdated figures, aiming for a 60 percent reduction by 2050. Even the annual 3 percent cut proposed in the motion calling for a new climate change bill does not go far enough. Time scale: immediately.
Second, use that target to set an annual carbon cap, which falls on the ski-jump trajectory.
Then use the cap to set a personal carbon ration. Every citizen is given a free annual quota of carbon dioxide. He or she spends it by buying gas and electricity, petrol and train and plane tickets. If an individual runs out, he or she must buy the rest from someone who has used less than his or her quota. This accounts for about 40 percent of the carbon dioxide we produce.
The remainder is auctioned off to companies. It's a simpler and fairer approach than either green taxation or the EU's emissions trading scheme, and it also provides people with a powerful incentive to demand low-carbon technologies. Time scale: a full scheme should be in place by January 2009.
Third, introduce a new set of building regulations with three objectives.
A: Impose strict energy-efficiency requirements on all major refurbishments. Time scale: in force by next June
B: Require landlords to bring their houses up to high energy-efficiency standards before they can rent them out. Time scale: to cover all new rentals beginnning in January 2008.