Expanding Gatwick is indeed worth that climate cost

So, they’ve approved it:

Gatwick airport’s £2.2bn second runway plan has been given the go-ahead by the transport secretary, Heidi Alexander.

Good. Of course there’s still this idiocy:

The cabinet minister is satisfied with adjustments made, covering issues such as noise mitigation and the proportion of passengers who would travel to and from the airport by public transport.

An idiocy we snarled at here.

But there will be those insisting that this isn’t worth the “climate cost”. No, no, don’t start shouting that there isn’t any. Perform instead that intellectual judo of taking their arguments seriously and thereby showing they’re still wrong.

The task is to - well, attempt at least - maximise human utility over time. Some of the things we do now will damage that future utility. Some of those things will not be carrying the full cost of that future damage - those so-called externalities. Therefore too much will be done now to damage that future utility. This is the entire argument about doing anything about climate change at all - as evidenced by Stern, Nordhaus, the IPCC and all the rest. So, we need to adjust prices in order that people bear now the costs they impose upon the future. The carbon tax.

Yes, yes, we can all say that’s not enough and all that. But that is the base logic behind all of this. We do too many things, and too much of them, that damage the future. But those things also have benefits now so we are trying to balance that utility over time.

Utility is, of course, defined by the person enjoying it.

But what that means is that if people are paying the full costs of the damage their activity does to the future then they should be allowed to get on with it. Because by their very action in paying that full cost they are showing that this is human utility maximising over time.

Nope, we don’t get to say that people shouldn’t value what they’re doing as much as they do. Utility isn’t imposed by the standards of others, it’s something decided by the individual doing the doing.

So, Britain has Air Passenger Duty. This is at rates higher than any reasonable (ie, non-Greenpeace or George Monbiot) estimation of the costs of carbon emissions. People are still willing to pay that to fly. We have just proven that despite - yes, despite - that worry over future costs emitting now is utility maximising over time.

So, of course the airport should be allowed to expand.

Now there’s just that rampant foolishness of trying to make sure people use the bus to get to the airport to deal with.

Tim Worstall