History books will likely look back on September 2016 as a major milestone for the world’s climate. https://t.co/x3C7ife8Ij
The end is nigh?
Against the backdrop of the failure of comprehensive climate change legislation and the ongoing attacks against environmental protections already in place, now feels like an appropriate time to turn to a more basic question: are we doomed?
A lot is riding on the answer, so it’s no surprise that both scientists and economists have put quite a bit of effort into fine-tuning their crystal balls. What is perhaps surprising is that the two groups can seem to arrive at such different conclusions. (This is a topic that both David Roberts and Matthew Yglesias have taken up recently, and I’m going to draw on both of their thoughts in this post.)
The current scientific consensus can be summarized broadly as follows: to preserve the environmental conditions in which humankind evolved and flourished, we need to stabilize atmospheric CO2 at 450 parts per million. Going above this threshold will put severe stresses on natural and manmade systems, increase the occurrence of extreme weather events, and raise the probability of potentially catastrophic runaway climate change. Further, as hard as the 450 ppm target will be to achieve, a growing chorus of experts claim that a safer limit is 350 ppm — which we have already surpassed.
Although the economic consensus isn’t as strong, it’s fair to say that mainstream expert opinion supports the following propositions: climate change is a threat, and the steps necessary to moderate that threat are both affordable and considerably less expensive than the status quo scenario. We should put a price on carbon emissions, both because fossil fuels have well-known negative consequences that aren’t currently accounted for, and because such taxes are a better way to raise revenue for the government than, say, taxes on earnings.
So far, so good. These two views differ in focus and degree of urgency, but they are compatible. Within the tight constraints of both our political system and current public opinion, it’s fair to say that the scientific and economic views are for practical purposes well aligned.
However, I’m asking a slightly different question: given the path we’re on, how worried should we be? And here the cracks start to appear. A lot of scientists give off an air of barely suppressed panic, conjuring visions of mass extinction, collapsed ice sheets, spreading deserts, and other calamities. Most economists, on the other hand, seem relatively placid. Continued economic growth, they feel, promises that the future world will be a richer and healthier place regardless of whether we are successful in curbing CO2 emissions. Climate change might make our grandchildren poorer than they otherwise would be, but they’ll still be much better off than us.
Are *these* views compatible? The short answer is, yeah, they probably are. It’s possible for the planet to go through some fairly severe and unpleasant changes and still support a lot of comfortable humans, if not nearly so many other creatures.
Environmentalists sometimes resist this notion because it seems like an argument for complacency, when clearly both the structure of our political system and the current pace of carbon emissions highlight a need for greater urgency. This isn’t just a theoretical concern; the more honest opponents of environmental regulation admit that climate change is real, but argue that we should kick the can down the road and let our rich descendents deal with it.
Nevertheless, urgency shouldn’t — and doesn’t — rest exclusively on a prediction of civilizational collapse. Matthew Yglesias does a nice job explaining the disparity between scientific and economic views of the future. In brief, scientists are good at understanding and describing technical problems, but tend to underestimate human adaptability. Economists, on the other hand, are good at identifying large-scale social trends, but can be frustratingly indifferent to short-term suffering:
> Imagine someone telling you in February of 1925 that he’s optimistic about the next 30 years. In 1955, he argues, per capita living standards will be higher than they are in 1925. In reality, the 1925-1955 period saw a Great Depression, Stalin’s Great Terror, the Holocaust & World War II, the partition of India, etc. It sucked. And yet per capita living standards were higher in 1955 than they were in 1925. It’s a very interesting and important fact about the past 200 years of world history that for all N, global GDP per capita is higher in N+30 than in N. But this doesn’t really suffice as an analysis of any particular problem. Avoiding the Depression, or Nazism, or Maoism would have been huge wins for humanity.
It’s hopefully uncontroversial to suggest that major depressions and world wars and genocide are things we’d be wise to avoid, even if we know in hindsight that they didn’t forever halt human progress. Likewise we should continue to be very concerned about climate change, even if a hotter planet doesn’t (necessarily!) mean full-scale Armageddon. Scientists are right: the consequences of climate change are going to be pretty bad, and possibly really, really bad. And economists are right: whatever the future holds, we’ll be doing future generations a big favor if we act to address the problem now. So let’s get on it.