The financial benefits of reducing CO2 emissions, and avoiding the climate change they would bring, is at least 2.6 times larger than the US government estimates. And, according to Laurie Johnson of the Natural Resources Defense Council in Washington, DC, and Chris Hope at the University of Cambridge, UK, they could be much higher. Undervaluing the damages, which play a part in how the US government makes decisions about climate issues, borders on insanity, Laurie told me. “What we have to ask ourselves is what our children are going to think of us,” she said. “We’re being very self-destructive, but also deeply unethical. We’re not even trying to minimise how much worse it’s going to get. They’ll look back at all this science and how everything is changing, and see how we treated the damages so trivially and did so little.”
In 2010 some of the top departments in the US government got together to publish the first estimates of the money value of benefits from CO2 cuts. The benefits come from avoiding losses through damage caused by climate change. Called the social cost of carbon (SCC), this value is important because it affects rules on CO2 emissions, such as those from cars and power stations. Using three models that linked climate and economics, the government departments decided that the SCC was $21 per metric tonne of CO2*. Thanks to its importance for future climate rules, Laurie had watched the value being calculated closely – and was worried about what she saw.
“One of the models includes infectious disease damage estimates that are highly questionable,” she told me. “The models also estimate net gains from agriculture from now up to 2300 globally. By contrast the insurance industries appear to be estimating $25 billion dollars for crop losses in the US this year. That’s just one year for one country, and their calculation is for more than two hundred years, all countries. It also estimates a couple of billion in extreme weather damages globally over that period. Last year, in the US alone, there was over $50 billion dollars’ worth of extreme weather damage. Overall, it’s a very problematic estimate.” While the faults are plain, correcting any of these areas with more accurate values is a big problem itself. So Laurie and Chris looked at two other areas that they also felt had been worked out badly, but were simpler to tackle. Read the rest of this entry »