Could climate change be good? Wikipedia’s article on “Regional effects of climate change” lists a wide variety of effects of climate change, all of which seem to be bad. That seems odd. Unless the world’s present climate system somehow represents the perfect ideal, presumably climate change should be good for some reasons. Why should we think the present climate system to be ideal? Is it because this is the climate humans evolved in, and humans are perfectly adapted to it? But that can’t be the case, because humans spread to most of the world rather quickly, and too recently for evolution to have altered us much. For the theistically inclined, one might say that God, in His wisdom, made the world ideal for man. But in the Bible, God tells Adam and Eve: “Be fruitful and multiply, fill the earth and subdue it.” In other words, we have divine endorsement to alter the environment. We certainly have altered the environment greatly since we came on the scene. We’ve been doing that for thousands of years. We’ve already adapted to many environments, from tropical rainforests to arctic tundras. Why should it be a problem to adapt to a world a few degrees warmer? Studies show that global warming will benefit some regions. Some plants in arid regions might benefit. One supposes that places like Canada, Russia, even New England, which are uncomfortably cold, could flourish in a warmer world.
Aside from the ethics of whether we have a “right” to alter the natural environment (I won’t explore that), much of the problem with climate change is that even if it doesn’t reduce the capacity of Earth as a whole to sustain a growing population, it probably will make some regions less amenable to human flourishing. The most vulnerable country in the world to global warming may be Bangladesh, a country with a dense and rapidly growing population which could see 11 percent of its land inundated if seas rose by 1 meter. It seems likely that the burden of adapting to climate change will fall disproportionately on poor countries that played a rather small role in causing it. Suppose that, as seems likely, other countries are benefiting, in the sense that their environments are becoming more conducive to agriculture, more capable of sustaining large populations. If Bangladeshis were allowed to emigrate to these countries, that probably wouldn’t reconcile them to the loss of their homes, but it would do much to prevent possible humanitarian catastrophes.
It stands to reason that open borders should be part of the environmentalist agenda. If we are altering the climate, we need to adapt to that, and migration, moving from the areas most damaged by environmental change to the areas most favored by it, is one of the most powerful instruments of adaptation available. If we want to avoid altering the climate, there will be some regions where human beings can live with the least damaging environmental footprint. We should make it possible for them to do so (and then maybe arrange a Pigovian tax regime to encourage them to).
UPDATE: A column titled Moving to Greenland in the face of global warming by Klaus Desmet and Esteban Rossi-Hansberg for VOX makes some related points.