If you haven’t been living under a rock recently, you will have noticed Extinction Rebellion (XR). This is the group of activists led by the globe-trotting, privately-educated Robert Boardman-Pattison and inspired in part by young Swedish protestor Greta Thunberg.

For much of April, they have been blockading roads and appearing on various media outlets demanding an urgent elimination of CO2 emissions that would indeed see us back in the stone age.

But you don’t have to miss the Palaeolithic era to share their concerns about climate change. While most people would surely agree that the group’s tactics are counterproductive, polls show that a significant number of people support their aims, which include the target of making Britain carbon neutral by 2025. This idea may sound appealing, but to follow it through in practice would be pointless, damaging and deeply irresponsible.

First, be in no doubt that eliminating the UK’s net emissions would serve almost no purpose at all. The UK’s emissions account for only 1.12 per cent of the global total. These are already decreasing in both relative and absolute terms.

But assuming that they weren’t, eliminating these tomorrow might only reduce global temperature rises by barely a fraction of a degree in 2041 (taking the mid-estimate from this report). Put another way, the UK going carbon neutral would delay temperature increases by a couple of months, at best. This is dramatically below the margin of error on any simulation (let alone what can’t be accounted for due to uncertainty).

Even so, such marginal reductions might be worth pursuing (and could perhaps open the way to more significant steps in the future). The problem here is that, while the benefits of these changes might be unquantifiably small, the costs are enormous.

It is no accident that wealthy countries have higher emissions on average. Carbon powers our cars, our air travel and our electricity grids. CO2 is produced in growing our food and in heating and cooling our homes. Even a pair of hemp sandals might cost around four grams of CO2 to produce. Eliminating these elements of our lives would be disastrous for society (except in the case of the sandals), and totally disproportionate to the marginal costs of an extra 0.005 degrees of warming by 2040.

Perhaps, however, the energy we currently use for all these things can be sourced renewably (or indeed from nuclear power). This may be possible, though not by 2025. The bigger issue is that it still isn’t worth it. Every adjustment away from carbon and towards new power sources also comes at a cost. A single wind turbine (onshore) might cost £2m pounds, a new nuclear plant several billion.

All of this represents scarce resources diverted away from new goods and services that consumers might enjoy, and instead towards replacing existing capabilities. It is the exact opposite of useful economic production. Those who believe in economic benefits from a “green new deal” are buying into a “broken window” fallacy which ignores opportunity costs.

None of this makes it wrong to be concerned about climate change, but the reason that we care about it is precisely because of the value that a stable climate affords to people in their daily lives. The costs (and benefits) of our changing climate need to be set against the costs and benefits of trying to stop such change.

Ostentatious sacrifices of the type proposed by climate protestors may appease mother Gaia, but the impact on the global climate will be negligible. The costs, on the other hand, are so great that to pursue them would be deeply irresponsible and amount to little more than vanity.

Written by Felix Hathaway

Felix Hathaway is a Research Assistant at the Institute of Economic Affairs.