Myles Allen, director of the Oxford Net Zero initiative, talks to Chris Seekings about the best way to decarbonise the world’s economy by 2050
Called “the physicist behind net zero” by the BBC, professor Myles Allen has played a key role in determining what is needed for humans to avert the worst impacts of climate change. He was instrumental in dismantling ideas of ‘safe levels’ of greenhouse gas concentrations, which dominated climate science and policy for a quarter-century prior to 2009, and also contributed extensively to the Intergovernmental Panel on Climate Change.
However, despite the fact that more and more countries and companies are committing to net zero, it has become an increasingly complicated and slippery concept during the past 15 years, much to Allen’s exasperation.
The science, he says, is simple: to limit peak warming, we must limit the total amount of carbon dioxide (CO2) we release, which means reducing ongoing emissions to net zero. However, the more net-zero goals have been adopted, the more vested interests have sought to redefine it and the best way of getting there. Allen says it is “obvious” we will generate more CO2 by burning fossil fuels than we can afford to dump, “so net zero means we need to stop fossil fuels from causing global warming before the world stops using them”.
A waste disposal problem
It is easy to imagine the enemies Allen might have made when he published his first net-zero papers in 2009. However, he says it was “striking” how quickly people embraced the concept. “It was faster than I expected, since net zero was a challenging finding for policy. It meant the old model of contraction and convergence didn’t work as there was no long-term sustainable rate of emissions for countries to converge upon,” he explains. “Yet the need for net zero was, in effect, mentioned in the Paris Agreement six years later, which I think is impressive.”
In 2009, Allen explained that the world had already released half of the CO2 that was consistent with limiting global warming to 2°C above pre-industrial levels. “We are now about a third of the way through the remainder, and have seen 1.25°C or so of warming, increasing at a couple of tenths of a degree per decade,” he says. “It’s obvious that we will generate more CO2 by burning fossil fuels than we can afford to dump in the atmosphere, and that’s why I focus on the need for large-scale CO2 disposal.”
For many, this is difficult to accept, exemplified by the Just Stop Oil protests that have recently been hitting headlines. For Allen, halting new fossil fuel licensing and production overnight is not going to happen, so other solutions are required. “We need to get rid of CO2. At the moment, the only way we get rid of it permanently on any scale is by putting it back underground.”
“It’s interesting how many people seem to have an extraordinarily vested interest in making this idea go away, and I don’t understand it”
The Carbon Takeback Obligation
In 2009, Allen first proposed that carbon capture and storage (CCS) should be made mandatory, and has since advocated for a ‘Carbon Takeback Obligation’ that would force fossil fuel extractors to clean up after themselves. The proposal would require fossil fuel extractors and importers to permanently store underground a percentage of the CO2 generated by +the products they sell, with this percentage increasing to 100% during the next few decades.
“We don’t need to be at net zero tomorrow, we need to be there by 2050,” Allen says. “The logical thing to do is to start by requiring companies to dispose of a small percentage of the CO2 generated by the products they sell and ramp that up over time. You could impose this as a simple licensing requirement: anyone who wants to sell fossil fuels in a jurisdiction has to get rid of CO2. If they don’t get rid of it themselves, they need a certificate to say that somebody else has got rid of it for them.”
If realised, he says, the obligation would create a huge “CO2 disposal industry” that would generate the certificates required by fossil fuel providers. Those without a certificate won’t be able to sell their product. “These certificates would become valuable, create high demand for CO2 disposal and develop that industry quickly – without all the cost being borne by the taxpayer.”
A study by Oxford Net Zero researchers suggests that a Carbon Takeback Obligation would provide an “affordable and low-risk route” to net-zero and could “stop fossil fuels from causing global warming within a generation”. Allen adds: “For what we’re paying for natural gas in Europe, you could capture all the CO2 it releases into the atmosphere and put it back in the ground twice over. Yet while everyone is talking about windfall taxes, that doesn’t seem to be part of the conversation.”
A licence to trash
Allen admits that some may hesitate to embrace CCS (either at source, or recaptured from the atmosphere) because of the perception that it would allow the fossil fuel industry to carry on extracting and producing forever. However, he argues that the industry would decline because it would no longer make economic sense. “If you include the cost of disposing of CO2, a lot of our fossil fuel resources would no longer look attractive,” he says. “There is this nervousness among the environmental movement about the fossil fuel industry being allowed to do anything at all, but the alternative to a takeback obligation is no obligation at all, just to go drill.”
Although the proposal is being taken seriously in countries such as the Netherlands, he says that leaders in the UK continue to argue about whether this should be seen as an alternative to an Emissions Trading System (ETS). “An ETS is a sensible way to find the least-cost ways of reducing emissions in the short term, but a bad way to incentivise CCS,” he argues. “The problem is that until the carbon price becomes predictably higher than the full cost of CCS, nobody’s going to do any CCS. We will have to wait until the 2030s before we start the build out of our CO2 disposal infrastructure, by which time it’ll be far too late for us to gain public confidence that it’s going to work. And that is assuming people put up with those high carbon prices, which is far from guaranteed.”
“For what we’re paying for natural gas in Europe, you could capture all the CO2 it releases into the atmosphere and put it back in the ground twice over”
He points to France’s gilets jaunes protests as an example of how rising carbon prices can fuel a public backlash, before describing the UK’s decision to launch a new North Sea licensing round for oil and gas companies as “golden opportunity missed” to implement the Carbon Takeback Obligation. “We have a choice: either we reduce global per capita energy consumption by around 50% by 2030, which we show no sign of doing, or we need large-scale CCS.”
Turning rocks into trees
One of the most popular routes for companies wanting to reach net zero involves offsetting via nature-based solutions – typically tree planting. The problem, Allen says, is that companies are not replacing like for like, instead taking carbon from the geosphere and placing it in the biosphere. On the other hand, CCS – liquefying carbon emissions and injecting them back into geological formations – is effectively “re-fossilising” the carbon.
“For biosphere emissions, such as from the food system, it will be appropriate to offset within the biosphere – like for like,” he says. “But if it’s coming out of the geosphere, you’ve got to put it back there.” He describes offsetting fossil fuel emissions via tree planting as “turning rocks into trees”, adding: “You might be able to do that for a decade or two, but that’s not a long-term solution.”
Another benefit to offsetting via CCS is the ability to quantify the emissions being sequestered. “The beauty of this is that we actually know how much CO2 is going back into the ground, just as we know what fossil fuels are coming out of the ground – this is well documented,” Allen says. “That is in contrast to arguments over nature-based solutions and forestry, where it’s hard to work out what carbon’s gone where, what would have gone there otherwise, and so on.”
Opening minds
The fossil fuel industry claims to support technological solutions to the climate crisis, but Allen says that this is typically the case only when others pay. “They’ve consistently said, ‘we’ll do carbon capture when there’s a business case’, which is another way of saying ‘we’ll do CCS when the government pays us the full cost of doing it and then some, so it’s profitable’. That’s a big reason why it hasn’t happened – a lot of people are understandably leery of spending a lot of government money on a technology that’s just benefiting the industry.”
He points to the US and Canada, which have substantial subsidies for CCS – a cause of much debate. “I recognise we need this technology, so I’m happy to see people investing in it, but I sympathise with the people who say ‘why the heck should we spend taxpayers’ money on this technology when these companies are making so much money?’ That’s why I think the obvious solution is regulation that requires the industry to do it.”
Allen stresses that the fossil fuel industry “absolutely” has the technical capacity to decarbonise the products they sell, and that the world can reach net zero by 2050, but says that this will require people to open their minds to new solutions, and for “the offsetting world to recognise that it needs to make a transition.” He adds: “It’s interesting how many people seem to have an extraordinarily vested interest in making this idea go away, and I don’t really understand it. We’re only seven years away from 2030, and emissions are still going up, so we’re obviously not going to stop producing CO2 in time. So we need to get rid of it, which means CCS to start with, and eventually direct air capture. I think a lot of people just need to wake up and smell the coffee.”
