Morning Must-Read: Paul Krugman on Roger Pieleke, Jr., 538.com, and Global Warming

Paul Krugman: Energy Choices: “Nate Silver got a lot of grief when he chose Roger Pielke Jr….

…of all people, to write about environment for the new 538. Pielke is regarded among climate scientists as a concern troll – someone who pretends to be open-minded, but is actually committed to undermining the case for emissions limits any way he can. But is this fair? Well, I’m happy to report that Pielke has a letter… that abundantly confirms his bad reputation…. Pielke:

Carbon emissions are the product of growth in gross domestic product and of the technologies of energy consumption and production. More precisely, this relationship is called the Kaya Identity – after Yoichi Kaya…. A ‘carbon cap’ necessarily means that a government is committing to either a cessation of economic growth or to the systematic advancement of technological innovation in energy systems on a predictable schedule…. Because halting economic growth is not an option, in China or anywhere else, and because technological innovation does not occur via fiat, there is in practice no such thing as a carbon cap.

This is actually kind of wonderful, in a bang-your-head-on-the-table sort of way. Pielke isn’t claiming that it’s hard in practice to limit emissions without halting economic growth, he’s arguing that it’s logically impossible. So let’s talk about why this is stupid…. Emissions reflect the size of the economy and the available technologies. But they also reflect choices… about what to consume… how to produce it… which of a number of energy technologies to use. These choices are, in turn, strongly affected by incentives…. Electricity consumption isn’t in a fixed relationship with GDP…. Even more important, there are many ways to generate electricity: coal, gas, nuclear, hydro, wind, solar…. That doesn’t mean that reducing emissions has no cost–but again, the idea that, say, a 30 percent fall in emissions requires a 30 percent fall in GDP is ludicrous…. Pielke’s fallacy… [is] the notion that there’s a rigid link between growth and pollution…. What we actually need is a change in the form of growth–and that’s exactly the kind of thing markets are good at, if you get the prices right. Anyway, I guess I should thank Pielke for his intervention, which has helped clarify how we should think both about energy issues and about him.