Paul's a good economist, especially in his textbook. His New Trade Theory was solid work, and he's extremely smart, but I'm stumped by this.

Krugman criticizes Roger Pielke, Jr. in this post.

He attributes an argument to Pielke that Pielke never made, and never came close to making. He says that Pielke argues that a drop in emissions will reduce GDP one-for-one, like a 30% drop in emissions will reduce GDP by 30%. Pielke never says anything like that -- never even mentions magnitudes, amounts, or numbers with respect to emissions and GDP movement, much less a one-to-one relation.

This is all based on a short letter Pielke wrote to the Financial Times. Pielke's point is based on the Kaya Identity, but Paul never presents it to his readers, and his column suggests he's not looking at it carefully. Here it is:

CO2 emissions = population * per capita GDP * energy consumption per GDP per cap * CO2 emissions per unit of energy consumption.

Pielke said that there's a trade-off between economic growth and CO2 emissions given currently affordable technology (i.e. fixing the last variable above); that we can't wave a wand and instantiate linear progress in affordable replacements for carbon energy; and that technological progress is not always predictable. Referring the equation above, Pielke probably means that to reduce CO2 emissions, we have to reduce one of the terms on the right side. He doesn't say which one. We can reduce CO2 emissions per unit energy consumption, but not by snapping our fingers. Green energy sources are still more expensive than traditional sources, so to go that route we have to spend more money.  Diverting spending from one sector to another doesn't actually increase GDP – if we all took the money we spend at coffee shops and instead spent it all at the Gap, that would not make our economy grow. Same drill if we divert from gas stations to charging stations (unless you can introduce other variables.)

Pielke's points are ho-hum things to say, almost mundane, perhaps overlooked. They're not controversial, since they happen to be true and well-undestood. These are somewhat descriptive claims, not very political. But Krugman goes off on a malice spree where he makes up the one-to-one idea and goes through the motions of dispatching a "stupid" and dishonest "concern troll".

Two things disturb me. First, as noted above, Krugman is wrong, and wildly so. His errors are basic, and in a Nobel laureate, strange.

Second, he's unbelievably malicious and just... dark. It makes me uncomfortable. He openly revels in his own malice, like when he says he was "happy" to discover that Pielke had no credibility. He gleefully revels in Pielke's alleged studipity by saying "this is actually kind of wonderful". What's going on here? Would you be happy to discover that someone was stupid? Are our brains' pleasure centers so dominated by our political selves? Ick.

It disturbs me how much malice there is in politics, whether in the climate debate, or economic issues, immigration, all of it. It's not appropriate for a scholar to conduct himself with such malice. Think about it. What has Pielke ever done to anyone? Why would you hate someone for disagreeing with you? To really, really hate them -- to insult them, and gleefully call them stupid in the New York Times -- why? It's not like he rigged a climate consensus study or lied about something. I would need a lot more than disagreement.

Okay, sure, if I slip into the perspective of someone who thinks AGW is a severe near-term crisis that calls for immediate and severe preventive action, I can see how I might view people like Pielke as obstacles, maybe even enemies of humanity. But I'd still have to be right in the things I said – being wrong or misunderstanding equations isn't part of the package.

Understanding complex realities like climate and economics isn't easy. We should all expect to be wrong with some frequency, and to disagree, and our wrongness should have no moral implications so as long as we're honest. We should be total buds with people we disagree with.

Do you have a piece of paper handy? If so, grab a beer and something to write with.

1. Write down all the names of climate scientists that you can remember -- anyone you've read about or seen. If you're a super cool person, you'll do this before you scroll down to the next step.






























2. Now, circle the names of the climate scientists who you like to read.

In many cases, I think skeptics will have written down more names of prominent skeptical or lukewarmer scientists -- perhaps Judith Curry*, Roy Spencer, Richard Lindzen, Roger Pielke Jr., or Lennart Bengtsson -- compared to the number of mainstream "consensus" scientists.

If that's what you did, why is that? Why do you only know the scientists who agree with your view? Why do you only read them?

This is what I've seen a lot of climate skeptics do: They come into the climate debate with preconceived notions, and they latch on to those handful of dissenting scientists who agree with them. They don't know the names of a lot of non-skeptic scientists, except perhaps for a couple of people they view as arch-villains. This is pure confirmation bias. You're less likely to get to the truth if you only read people who agree with you. Do you read champions of the "mainstream" view like Gavin Schmidt, Kevin Trenberth, and Drew Shindell? Why not?

A critical reason why this approach is faulty is that skeptical climate scientists are significantly outnumbered by scientists who are more confident in human-caused warming and in future warming scenarios. I think some of the research on the climate science consensus is garbage, but even if the numbers are inflated, it looks like a large consensus will still be there if you fix the studies and revise them downward (there's a lot of room to go down from 97% and still have a very high number). That said, those of you who are gung-ho pro-consensus might want to at least deploy some attention to the minority scientists. Minorities can be right.

If you're looking in on the field from the outside, and you don't have the background to evaluate the scientific research in depth, then you ought to pay at least as much attention to the majority as to the minority. I want to be clear -- I agree that a scientific consensus won't always be correct. History is replete with examples, and most recently I think some of the consensuses put forward on diet and nutrition were flawed. Moreover, I really don't like the centralization of science into formal authorities and pompous organizations, especially when they push partisan politics. A scientific monoculture abrades against the epistemic and sociological requirements of good science. But climate scientists are not morons. They know about the sun. They are aware of volcanoes. They've heard of cloud feedbacks. They have answers to most of your arguments, and you might want to check them out.

* I don't have a problem with skeptical climate scientists. I don't know enough to have a problem with them, and I have a lot of respect for Judith Curry, Richard Lindzen, and Roger Pielke, Jr. I'm aware that just saying that will infuriate some AGW activists... sigh. All I'll say for now is that evil is somewhat rare, in climate science as much as anywhere else, and I get nervous when a field has no dissenters, or when dissent is demonized. I like contrarians, and I think they're quite valuable even if they're wrong. More on that another time.