Real Climate has a good post regarding the probability of climate change affecting extreme events. This is (at least in part) a response to Roger Pielke’s post at the 538 blog claiming that climate change is not increasing the cost of extreme events. Most of the statistics is above my head, but I think some of the contention is missing the forest for the trees.
As discussed by Real Climate, extreme events are by definition rare so determining a clear “cause” is difficult. The physics behind all this — higher temps, more moisture in the air, higher sea levels, etc. — is loading the dice in favor of heat waves, droughts, hurricanes, and more. But, can you really say climate change is the “cause?” Few, if any, scientists can give a definitive Yes or No. But, if the question is whether climate change is making matters worse, then the answer is more clearly, Yes.
The analogy I think of is whether speeding causes a car accident. Screaming down a country dirt road at 120 mph may cause an accident simply because you don’t have the reaction time to avoid that herd of wandering cows. But, even here you have both explicit and implicit extenuating circumstances: frakking cows on the road(!), poor traction on gravel, limited sight distance, time of day, weather, type of vehicle, and more. While speed may be the dominant factor, it is not the only one. Conversely, think about the damage to the car (much less those poor, innocent cows) at 55 mph? Or 25 mph? Maybe the accident would still happen, but the aftermath would be much less apocalyptic.
Which gets back to Pielke’s contention that costs are not increasing due to climate change. This thesis is more along the lines of my question than a cause-and-effect question. I concur with the rebuttals (see more below) that Pielke omitted a lot from his analysis. Another overlooked point is what is included in the cost calculation. Harking back to the car accident analogy, the 120-mph accident is an outlier and likely to make the news. People will mock the driver on Facebook; PETA will protest; Twitter will go aflutter. But, how often do you hear or think about the 90 or so people (pdf) that die in traffic accidents every day. Or mountain pine beetles migrating farther north and east. Or the gradual extinction of plants and animals. Or oysters that can’t form their shells.
For further reading: In addition to the Real Climate post noted at the beginning of this post, there has been a lot of push back on Pielke’s article. ThinkProgress, Huffington Post, or Climate Science Watch, among others. Even 538 is looking to publish a rebuttal.