Tim Worstall explains what a carbon tax is supposed to do, as opposed to what many environmental activists want it to do:
The essential economic analysis is that carbon emissions are an “externality.” There are costs to third parties of the freely chosen activities of consenting adults. If there aren’t such third party costs then the adults get to consent – as long as your bedroom contains only those freely consenting adults then what goes on there is up to you. But if there are those third party costs – say, the noise from the enjoyments causes lost sleep among the neighbours – then some societal power to force an adjustment seems reasonable enough.
Again, economics analyses here by suggesting that we’ll get too much, or too many, of those third party costs if people aren’t paying for them. If we’ve not got to pay to soundproof the orgy then we’ll have more orgies than if we do. It’s fair that we insist upon such soundproofing perhaps. But sometimes we cannot insist upon such direct actions – then we’ve got to try and change the price system. Which is what the carbon tax does.
There are benefits to using fossil fuels – transport, heat, cooking and so on. Given current technological levels immediate banning would mean billions die – commonly thought to be a Bad Thing. But there are those costs imposed upon others as well in the climate change the emissions cause. The answer is that we look to that greatest good of the greatest number, the utilitarian answer. Where emissions produce more value than the damage they cause – including over time – then we want them to continue. Where they don’t then we want them to stop. That way we get the maximum possible value being created and thus all humans – over time – are as rich as we can be given current technologies.
Calculating what this number is, this tax rate, is also known as determining the social cost of carbon emissions. The Stern Review may or may not have exactly the right number but it’s a good enough starting point, $80 per tonne CO2. Say 50 cents or so per gallon of gas. Slap that tax on and we’ve corrected the price system. People who use gas are now paying the environmental costs of their use. So, anything they use it for must create greater value than the damage being caused. We’re copacetic at this point, we’ve the optimal level of emissions.
Note that this logic still works whatever you think of the rate. 1 cent or $100 a gallon, the logic is still the same, we’re only arguing over what is that social cost of carbon. Stick a tax on of whatever it is and we’re done.
Even if climate change isn’t a problem, or isn’t happening, we do still need some tax revenues somewhere. It’s also better to tax consumption than incomes or capital, better to tax things inelastic in demand with respect to price than those elastic. Fossil fuel consumption taxation is a consumption tax and the demand for fossil fuels is, in the short to medium term at least, inelastic. We’re fine with fuel taxation therefore.
For a quick backgrounder on the concept of externalities, MR University did a video on this a few years back. For reasons to worry that your government might not be quite as revenue-neutral in imposing a Pigouvian tax, Warren Meyer also has doubts.
