Of all the silly ideas about climate change

There's a good reason why all the economists looking at climate change insist that there should not be detailed plans for this and that to do with the subject. Assuming that something must be done stick the one crowbar into the price system and allow those markets, that calculating machine of the economy, to do the detailed work.

Do not, just do not, try to make those little plans for each nook and cranny. Like, for example, do not try to have industry or sector specific carbon allowances

A radical way to cut emissions – ration everyone’s flights

Sonia Sodha

No, really, just no.

Instead we should look to carbon trading schemes for inspiration. In schemes running in the EU and some areas of the US, international organisations or governments sign up to a total limit on carbon emissions. They then issue companies with permits that allow them to emit a certain amount of carbon. It’s then up to the companies to trade the permits. Companies that want to emit more can buy permits from those that manage to reduce their carbon emissions.

We could develop a similar system for flights. Everyone could be given an air mile allowance – say enough for one long-haul return flight a year, or three short-haul flights, so people with families on the other side of the world could see them once a year. If you don’t want to use your allowance, you could sell it off in a government-regulated online marketplace. If you’re keen to do a holiday a month, you’ll have to buy your allowance from someone else.

The reason being that there's nothing specific about emissions from airplanes - or any other source. They're all the same gas, it all has the same effect - whatever that is. Thus we want to be as rich as we can within whatever the limit we allow ourselves.

Which means using that that economists' favourite, substitution. We don't want to limit emissions from farming, from aviation, from land transport, shipping, per se. Whatever the limitation is we want to limit all such - meaning that we're not just happy but overjoyed if emissions in one sector go up as those in another go down. Say, just imagine, that a fully loaded car has fewer emissions on a journey than a train - true for small cars properly full of people. Our desired output is that people get there with the fewest emissions - we'd thus be happy with rising car emissions and falling train ones to get that task done.

Or to adapt Adam Smith, the transport emissions from taking Bourdeaux to Scotland are lower than the local emissions of trying to grow the wine north of the Tay. We would be happy with such substitution as we'd still gain the booze and also lower emissions.

Thus we don't want industry or sector specific schemes - we want substitution across sectors as well as within them.

Whatever views on climate change itself it's still important that we stamp on delusions like this one proffered. We're looking for the greatest human utility within whatever the limits are. That means we cannot impose strictures just on the one activity, whatever it is that is done must allow for substitution across sectors and activities.