Peter Singer, famous ethics philosopher, recently spoke at the Carnegie Council. I wasn’t there, but I listened to the podcast. In it, he stated the case for acting now on climate change in a very simple and clear way.
The two arguments against acting on climate change are that it either not happening, or not caused by human action. Singer’s argument neatly addresses both of them by circumventing them. Singer’s statement can be read in full here, but the basic gist is a simple cost and benefit argument.
The cost of global warming, once it is in irreversible effect, has been estimated to be up to 2.8% of global GDP. Global (nominal) GDP now is now around $70 trillion, so even if we assumed that GDP wouldn’t be higher at the time that global warming really kicks in (an unrealistic assumption), it would still be a cost of 2 trillion per year.
If we look at this cost alone, the second argument (whether it is caused by human action), becomes irrelevant – the costs will be there for us to face regardless of the cause. The first argument then becomes a case of probability-weighted cost. Some people might still question whether global warming is indeed happening. Let’s put a probability on that doubt, perhaps, to be generous, we argue that it is only a 20% likelihood (unrealistically low).
The expected cost then is $400 billion/year. Not to mention of course that this will be unevenly distributed across the world. This cost, for the world as a whole, is the cost we should compare with when we look at the costs of starting to tackle it (costs that will only go up the longer we wait). Looking at it that way, as a simple cost/benefit of taking out an insurance policy, taking action now seems like a very cheap insurance against a potentially very expensive problem. For any other similar risk, we would take out insurance. Not taking it against a risk such as global warming, that could wreck the planet, seems perverse. It suggests that we value future human lives much, much lower than current ones, to a higher degree than previously thought.