What a simple but awesome image, eh! (source, via)
Speaking of global warming and icebergs, William Nordhaus continues to be annoyed, for all the right reasons, at the group that penned the WSJ op-ed and are now critiquing his comments. Nordhaus writes:
Climate scientists have moved way beyond global mean temperature in looking for evidence of human-caused climate change. Scientists have found several indicators that point to human-caused warming, including melting of glaciers and ice sheets, ocean heat content, rainfall patterns, atmospheric moisture, river runoff, stratospheric cooling, and the extent of Arctic sea ice. Those who look only at global temperature trends are like investigators using only eyewitness reports and ignoring fingerprints and DNA-based evidence.Nordhaus is clearly pissed, right? He makes a wonderful point about how rational people ought to think about uncertainties:
We sometimes hear that we cannot act because scientists are not really 100 percent sure that global warming will occur. But a good scientist is never 100 percent sure of any empirical phenomenon. This point was captured by the following comment on scientific uncertainty by the distinguished physicist Richard Feynman:Oh well ...
Some years ago I had a conversation with a layman about flying saucers…. I said, “I don’t think there are flying saucers.” So my antagonist said, “Is it impossible that there are flying saucers? Can you prove that it’s impossible?”“No,” I said, “I can’t prove it’s impossible. It’s just very unlikely.” At that he said, “You are very unscientific. If you can’t prove it impossible, then how can you say that it’s unlikely?” But that is the way that is scientific. It is scientific only to say what is more likely and what less likely, and not to be proving all the time the possible and impossible.jThis story is a reminder about how good science proceeds. It is possible that the world will not warm over the coming years. It is possible that the impacts will be small. It is possible that a miraculous technology will be invented that can suck CO2 out of the atmosphere at low cost. But in view of the evidence we now have, it would be foolish to bet on these outcomes just because they are possible.