Friday, April 16, 2010

What If

I'm not a global warming denier; I accept the consensus view of climatologists that anthropogenic global warming is real. I am even willing to accept that it's worth doing something about.

It is my understanding, however, that the earth has been in a lengthy period of remarkably stable climate for some time, and that sometime "soon" (I'm not sure what that means in climatological terms--it could mean a thousand years from now as far as I know) we're due for some a cooling cycle. I can't find any nice summaries of the science on this, so let's just ignore my ignorance and suppose that we found out that global cooling was about to happen in the near future. Suppose also that this cooling would have serious implications for humans and for species around the world.

What would environmentalists want to do in this case? Would they be in favor of letting the world cool down, possibly leading to human suffering, and the extinction of many species? Would they be in favor of trying to warm the world somehow (not necessarily by increasing CO2 emissions--they might not like ocean acidification or some other side effect)? I don't know what their answer would be. Maybe different environmentalists would answer differently. I think the answer says something important about the opinions of the person answering, though.

I think economists would be in favor of doing whatever cost-benefit analysis supports, even if that means trying to manipulate global temperatures to avoid the costs of accommodating rapid climate change.

1 comment:

Mons said...

I don't think that it is climate change, per se, to which environmentalists primarily object. There seem to be two separate issues here. The first is that human activity is inarguably causing non-optimal change in the earth's natural systems. Climate change is simply the one large-scale indicator of this change which might directly and visibly affect everybody. The second is the possible negative outcomes from this change itself of course. However the second isn't really as specifically concerning as the first.

Global climate change, as you point out, happens from time to time due to various shocks (solar activity, meteor impacts, volcanic activity), but the net effect could be positive or negative. Global warming floods some areas, but increases the growing season in others. It shrinks the habitat for some species, but extends it for others.

However, global climate change is, believed to be, just one symptom of a larger issue - human-caused degradation and depreciation of the stock of natural capital. Perhaps in a similar manner to the increase in capital depreciation during WW2 - high capacity utilization with shortages in (or in the environmental case, a total lack of) repair and replacement parts. The fact that this anthropogenic change is so endemic and has progressed so far that it can affect the global climate is the true issue.

So, even if a cost-benefit analysis of a shift in global temperatures came out near zero or even positive, that's not the only factor at play in the climate change debate. There are still all the other activities - the ones which cause climate change - which have non-climate environmental costs.

If we experienced another little ice age, as we did a few hundred years ago, the issue would be completely different, I think. In the end, I doubt that the environmentalists would be advocating for human intervention into the global climate. While economists may be maligned for the heterogeneity of their macroeconomic predictions/proscriptions, weathermen and meteorologists are not much better. The climate is at least as complex a system as the aggregate economy, and so I think the focus would probably be on micro solutions to the exogenous shock on the climate, rather than an attempt to intervene directly to stabilize the climate cycle.

Or perhaps in the future we'll be engaging in counter-cyclical climate intervention in order to minimize the costs of wild swings in temperature etc. Or perhaps I'm just rambling.