Professor Kevin Anderson:

By definition, we may not like the language of rationing. In the UK, it is not the kind of language people like to use, but a carbon budget is a ration. One has to live within that ration; there is no neat way out of it. We can change the word to “fair share” but it is still a ration. You have got to live within the ration whatever you do. We can use the sorts of things that Professor McMullin referred to, such as technology, personal carbon allowances and stringent frequent flyer levies, not levies that allow people to pay just a few pence to fly more regularly but levies that stop people from flying more than twice, three, four or five times per year.

If there is a climate emergency — let us assume we are honest about that — why are we selling any SUVs? There should be no SUVs in any forecourts. If they are in forecourts, they should go back to the producer to be dismantled and converted into something much smaller. If there is a climate emergency, SUVs should not be sold. If we are selling SUVs, we are not acknowledging a climate emergency. There is a nice logic there. A climate emergency can be defined by whether there are SUVs in forecourts or in front of people’s houses. That is the sort of change we are talking about. No car should be sold that emits over 100 g of carbon dioxide per kilometre, starting from now. It should be tightened by 10% every single year. That would get us out of all internal combustion engine cars by 2025.

If there is a climate emergency, let us take Covid as an example and learn from what we did in that regard. In Ireland last year, transport emissions alone reduced by 15.7%. This was driven not by climate policy but by Covid policy. It is true that Covid policy was not particularly successful in driving emissions down elsewhere. Housing emissions went up by about 9% and agriculture emissions went up again in Ireland, but we should examine what was successful and ask why it was the case and what the equity implications were.

On the points raised on issues of burden, we should rethink some of the economics. If a low discount rate is applied to the likes of power generation, fossil fuels will be much more expensive than renewables. As soon as there are discount rates of 5% or lower, renewable power is cheaper than fossil fuel power every time. The only reason fossil fuels ever look cheap is that we apply a high discount rate. We should use the tools of economics to drive these things but ultimately we have to live within our carbon ration. That ration is determined by the fact that we have a certain carbon budget at global level that we have to allocate fairly.