The US, almost unique in the world, is roiled by a vigorous debate on climate change. The President is trying to move forward, but the steps so far do not seem to go far enough or fast enough for many of us, especially environmentalists.
The reality is that we cannot actually know for certain what the future will be – whether or not global warming will be serious. Unlikely as many of us who follow the science think, the science could be wrong! And, even skeptics have to admit if they’re being honest, there is some chance that they are wrong and the science might be right. Given this, it seems to me that we want to minimize the likelihood of the worst results that might occur. And, I think that this matrix below helps us understand how to make that decision when there is this kind of uncertainty. (Note: This is not original with me; see this video.) There are two conditions about reality:
- Climate warming theory, i.e., significant climate change exists and is being caused by humans, is either wrong (column 2) or correct (column 3).
- Do we do something about it? Yes (row 2) or No (row 3).
The resulting actions and consequences of our social decisions are shown in the lower two rows.
|Is Climate Warming Theory correct (columns 2 and 3)?
Do we do something about it or not (rows 2 and 3)?
|Co 2–NoSignificant Anthropomorphic Global Warming (agw) Does Not Exist||Col 3–YesSignificant Anthropomorphic Global Warming (agw) Exists|
|Row 2–Yes, we act||We act and have spent a relatively small amount of our resources to get to where we want to be anyway – a cleaner, healthier environment, but we did it sooner than we otherwise would have (see William Nordhaus)1||Good – we act and so we’ve dealt with the issue appropriately, mitigating the problem and adapting to what has already happened|
|Row3–No, we do nothing||Good — we do nothing and life goes on with the usual chaos. wars and mayhem that we’re used to||We fail to act and while the planet will be okay, (it has survived 5 extinction events), there will likely be:
Very serious sea level rise
Disruption of food supplies
Huge social dislocation, e.g
migrations of masses of peoples resulting in serious conflicts and likely widespread deaths
Possible global extinction event
So, if we as a society don’t believe in global warming and there is no significant warming (box 3,2), or we believe in anthropogenic global warming and we prepare for it (2,3), everything is hunky-dory and we can live on more or less “peacefully” (i.e., the way we do now).
If, as a society, we decide to go ahead and prepare for anthropogenic climate warming and there is none (2,2), we will have spent perhaps modestly more than we had to get where we wanted to go anyway.
However, if we decide to do nothing, and human caused global warming exists (3,3), then we are in deep, deep trouble! We face the likelihood of extensive disruptions and, in the worst case, a civilization-ending extinction event. On the bright side, the world will continue to exist; it will just start over again.
It seems to me that a logically conservative solution to this problem is to assume agw exists and that we need to do something, even if we think it is unwarranted – simply because the possibility of the (3,3) consequences are so bad we must avoid them even if their likelihood is remote!
1 William Nordhaus, The Climate Casino Risk, Uncertainty, and Economics for a Warming Planet, New Haven: Yale University Press, 2013
2 Elizabeth Kolbert, The Sixth Extinction An Unnatural History, New York: Henry Holt and Company, 2014.