How to talk to a climate change contrarian (if you must)
Nate Silver’s hiring of noted stats whiz Roger Pielke Jr. to write for FiveThirtyEight sparked a minor internet scrape last month over climate change, extreme weather, and how those issues are covered in the press. Pielke made his career repeatedly accusing climate scientists of scientific malfeasance for exaggerating the link between climate change and extreme weather (see here for dozens more). His latest effort was another entry in the canon, arguing that the rising economic costs of extreme weather had little to do with climate change.
Now the Breakthrough Institute, which is about as troll-y as they come with regards to climate change, is out with a true-to-form defense of Pielke, claiming that a new, devastating report from the United Nations Intergovernmental Panel on Climate Change entirely vindicates his approach to weather disasters. (I know, I know, I've called on the universe not to feed the trolls, but sometimes I’ll take requests.)
As is typical for Breakthrough, Pielke, and other climate change contrarians, the debate they're trying to have is almost totally pointless. It’s long past time to kill forever the idea that quibbling over the current costs of weather disasters matters either for climate policy or politics. When it comes to climate change and extreme weather, one simple fact takes care of the vast majority of what’s really important. You ready? Here it is, drum roll…
More global warming means more extreme weather.
To put it another way: Why do we care about climate change? Because it could cause serious, potentially catastrophic damage to our civilization. Extreme weather is a big part of how this will happen, according to the new IPCC report, which even Breakthrough and Pielke apparently agree is a good source:
Impacts from recent climate-related extremes, such as heat waves, droughts, floods, cyclones, and wildfires, reveal significant vulnerability and exposure of some ecosystems and many human systems to current climate variability (very high confidence). Impacts of such climate-related extremes include alteration of ecosystems, disruption of food production and water supply, damage to infrastructure and settlements, morbidity and mortality, and consequences for mental health and human well-being. For countries at all levels of development, these impacts are consistent with a significant lack of preparedness for current climate variability in some sectors. [IPCC]
It’s really that simple. Organized science is highly confident that unchecked climate change will cause more extreme weather in the future, along with a grim parade of horribles. So we should stop the carbon pollution that causes it.
The Pielke post that kicked off this whole mess is about an ancillary question: is the economic damage from past natural disasters the result of climate change? Right away we’re in trouble, because extreme weather events are by definition rare and random, and there have been only a few decades on record that have been much hotter than average. As this post explains in detail, with the exception of heat records, we simply don’t have very much data yet on the question, and it will take a while for the statistics to shake out.
In contrast, the IPCC's conclusions above are more powerfully based on scientific knowledge: quantum mechanics tells us that greenhouse gases trap heat, and climate models tell us that will cause more extreme weather.
But remember, Pielke is asking a narrower question still: not just whether extreme weather events are becoming more common, but whether the economic damage thereof is the result of climate change. Now we’ve got little data and confounding factors! As Pielke points out, a higher GDP does mean that there will be more expensive stuff for natural disasters to destroy, thus bumping up the financial cost of extreme weather. But a higher GDP also means there will be better construction quality and disaster prediction. Compare the death toll from the 2010 Haitian earthquake to that of a much, much stronger one in Chile. (Earthquakes have nothing to do with climate change, of course, it just gives a sense of the problem with Pielke's logic. See here for more.)
But whatever. When it comes to the big issues, none of this matters. It's a question that might make a nice dissertation in 20 years or so, but right now it's a D-list scientific inquiry at best.
Economic damage is a completely cockeyed way of looking at any of this. Poor countries are going to be hit hardest by climate change, but since they’re poor the damage isn’t going to be very "expensive." As some dude named Nate Silver showed us back in 2009, you could delete something like 3 billion people off the face of the Earth and it would only add up to 5 percent of world GDP. What happened to that guy?