Today, 9th September 2021, BBC news includes a report which claims that most remaining fossil fuels – 90% of coal, 60% of oil and gas – must stay in the ground, “scientists say”. The UCL study is reported in Nature.

“Scientists say” suggests that scientists all agree, something the BBC frequently implies. In this instance, it’s curious that a recent episode of the BBC Sounds series on 39 Ways to Save the Planet is entitled Polluter Pays, in which the Oxford scientist Myles Allen argues that essentially all we need to do to sort out climate change is to force oil companies to suck CO2 out of the air. If he is right, then there is no need to keep the remaining fossil fuels in the ground – we could dig them up, use the energy, capture the CO2, and store it underground. Capturing the emissions at the point of combustion is cheaper than extracting them from thin air, but most of the emissions (about 90%) associated with humanity’s use of oil and gas occur far away from the refineries – in the vehicles we drive, the planes we fly in, and the buildings we heat. So in order to sort out climate change, the industry will need to rely primarily on thin air retrieval, also known as direct air carbon capture and storage (DACCS).

As variously noted – including in this blog in March 2020 – Allen’s idea requires a lot of money and energy, quite apart from international regulation of the oil majors and international agreement on how and where to store all the CO2. Money: based on the Committee on Climate Change’s estimates for the costs of DACCS of CO2 (6th carbon budget), we would be looking at thousands of pounds per person on the planet (more for rich Westerners presumably). Energy: to suck an amount of CO2 from the atmosphere that is comparable to what we currently put into the atmosphere (about 35 billion tonnes per annum) would increase global primary energy consumption by 10-20% just to operate the vacuum cleaner.

In the Polluter Pays podcast, there is the curious suggestion that if oil companies try to push up prices to cover the cost (several trillions of pounds per annum), they could be out-competed by renewables. Which alas would defeat the whole purpose, as they wouldn’t be around any more to remove the CO2. For this to work, everyone will end up paying as the cost dwarfs oil company financial reserves; “polluter pays” is largely a myth, even if we use oil company reserves as an initial down payment.

To be fair, no-one knows how much CCS capacity (including DACCS) will be in place in 2050. The UCL study is probably more sensible, and certainly more mainstream; and it avoids one of the pitfalls of Allen’s idea, which is that no-one else does anything because they believe in a technological miracle put into effect by oil companies. Either way, it’s a striking coincidence of diverging scientific opinions, which the BBC doesn’t seem to notice in its reporting.