It’s perfectly possible to remove CO2 from the atmosphere - Professor Myles Allen, the physicist behind net zero

Professor Allen won a place at Oxford to study Physics and Philosophy, although English was his favourite subject at school. But he took the science route 'because it was there’ (as Mallory said about Everest). A self-confessed ‘nerdy teenager’, he smiles, there were no climate-related courses available to him in those days, and he would not have been interested anyway. But, he says, ‘Chris Llewellyn-Smith (one of his undergraduate tutors, and Director of CERN and recently-retired Director of Energy Studies in Oxford) made it very clear to me that I wasn’t clever enough for a career in theoretical or particle physics...’

That appeared to be the end of an academic career. So how did he end up as an internationally-renowned scientist, government adviser, sought-after commentator with a media nickname?

I wasn’t clever enough for a career in theoretical or particle physics,' says Professor Allen...So how did he end up as an internationally-renowned scientist, government adviser, sought-after commentator with a media nickname?

It was a roundabout route. After graduation, he went to Kenya to work for the United Nations Environment Programme. At the time, climate change was just emerging as an issue. But the young graduate was much more engaged with his work in East Africa. He says, ‘I was really fortunate to be in Kenya at that time.’

But two interventions sent him back to Oxford – inadvertently onto the climate science path. The first came from his boss in Kenya, who suggested he take a doctorate, for the sake of his UN career.  He returned to the university, to join David Anderson’s oceanography group. It was not the easiest transition: 'It’s hard to get back into physics after even a couple of years out’. A rainy Oxford, where he returned after just one term, did not compare with East Africa. But a chance encounter saw him return to his studies.

‘I had gone back to Kenya over the vacation and they wanted me to take my old job back, when some friends and I climbed Mt Kenya. On the way down, we met a very fit, albeit middle-aged man with a stick and a beard. He appeared out of nowhere and asked what we were all doing. He went round the group.

‘When he came to me, I said I was doing a doctorate at Oxford in oceanography. He immediately asked ‘which ocean?’ The Indian. And then, like the scene from Monty Python, he said, "Does your model have a closed or open eastern boundary?" At the time, it was closed, which was clearly the wrong answer. He said it should be open.’

The bearded man turned out to be Stefan Hastenrath, a world expert on tropical climatology on his way to study the retreat of the glaciers of Mount Kenya. So the DPhil student went back to Oxford to fix his model – and has left only briefly in the intervening 30+ years. Initially, he was working on natural, chaotic, climate variability, but over time, the science of human-driven climate change attracted the young postgrad.

'The physics was understood [in terms of CO2’s potential impact on warming],' he says. ‘But when I started in 1989 it was still a prediction. We didn’t see significant warming at that point, for reasons we understand well enough now, but were still obscure back then.’

The key to preventing climate change is reducing carbon dioxide emissions to net zero

Professor Allen

Within a few years, though, evidence was beginning to emerge and Professor Allen has worked on the scientific problem ever since – hence the Net Zero soubriquet. The key to preventing climate change is reducing carbon dioxide emissions to net zero, insists Professor Allen. It is a scientific fact he and others established in the late 2000s. And he has been talking about the implications ever since.

Doesn’t he get sick of saying the same thing? (In 2012, he jokingly referred to climate change as ‘so last decade’.) Not really, he insists, ‘The debate has moved on. Most people no longer question if climate change is happening.’

But, talking on the hottest day of the year so far, does he get tired of the media asking if every weather event is evidence of climate change.

Climate change is not a matter of faith for the physicist...Professor Allen knows climate change is real, because of the science, and knows as well, for the same reasons, that there are real (and relatively straightforward) solutions to the climate crisis

‘We don’t get as many calls as we used to,’ he smiles. Climate change is not a matter of faith for the physicist. He is not likely to glue himself to the baking hot road outside – or to anything else. He knows climate change is real, because of the science, and knows as well, for the same reasons, that there are real (and relatively straightforward) solutions to the climate crisis.  Professor Allen is very much the physicist, trying to simplify things, come up with solutions to problems.

‘Some subjects seem to be about making things complicated,’ he laughs. ‘Physics is about making things simple.’

He has clearly adopted this scientific approach in other aspects of life. Professor Allen explains, he and his wife, Professor Irene Tracey (yes, the future Vice-Chancellor), have adopted this methodical approach to work. They agreed at the outset that he would follow her, from Oxford to roles in the US and back again to roles in Oxford – since it is much more difficult to secure experimental research positions (‘she needs a multi-million pound scanner – I just need a desk and a laptop’). Professor Tracey is professor of anaesthetic neuroscience and researches pain. If they were to work in the same town, it made sense for her secure a place, and him to follow.

How does he feel about being the first, or is that second, gentleman in the university...[as the husband of] Professor Irene Tracey [the soon-to-be Vice-Chancellor]?

It also made sense, he says, that he took extended paternity leave when their youngest child Jim was born, since Professor Tracey had just been appointed to take over the Oxford Centre for Functional Magnetic Resonance Imaging of the Brain. At that time, shared parental leave did not exist, ‘but my Head of Department, Roger Davies, was incredibly supportive: still not quite sure how – best not ask!’ He took a year off from work and mostly stayed at home, although, he says, ‘Jim did have to sit through more statistics lectures in his first year than is probably healthy.'

‘It was a really nice year,’ he remembers. He is under no illusions that the novelty of a father taking parental leave in the early 2000s meant there was no damage to his career.

In many ways it helped being a bloke [taking parental leave], people didn’t think about it…but it was easier for me to take time off. Plus, Oxford and the department have been really supportive

Professor Allen

‘In many ways it helped being a bloke, people didn’t think about it…but it was easier for me to take time off. Plus, Oxford and the department have been really supportive.’

His experience may not be typical, but it helps highlight that it is possible to have a really outstanding academic career and a family. He and Professor Tracey are proof positive.  

He now sits in both Physics and Geography, as Professor of Geosystem Science in the Environmental Change Institute and Director of the University’s new Oxford Net Zero initiative. Nevertheless, he was always able to do the school run, and was going to watch a sports competition that afternoon. But how does he feel about being the first, or is that second, gentleman in the university, once Professor Tracey takes office? Typically, he laughs.

What does he do, when not at work?

‘Walk the dog,’ he replies simply. ‘We’ve got a lockdown puppy, who has his own Twitter account – not that I am responsible for it. But I like to walk the dog… He’s called Geoffrey, with a G...Geoffrey Biscuit.'

A TED talk by Professor Allen https://go.ted.com/mylesallen

Keeping things simple is the key to solving climate change, he insists. There is a lot that can be done, in terms of renewable energy and reducing emissions but, maintains Professor Allen, we will not achieve our climate goals by 2050 if we focus solely on the switch-over to renewables and nuclear power. 

‘Britain could stop using CO2 entirely. We have great renewable resources, so we could just about achieve our goals by 2050,’ he says, pondering the problem.

That’s a relief. But, he adds, in his matter-of-fact, travel-industry-apocalypse way you would expect from a scientist, ‘We might have to stop all flying and international shipping… everything would have to come through the Channel Tunnel. And that's Britain: a rich country and the one that really started burning fossil fuels: imagining making the same ask of Mozambique.’

For more than a decade, ever since he identified the need for net zero, Professor Allen has championed...carbon capture and storage 

But, he insists, there are better, less extreme, solutions – ‘very simple, but not easy’. For more than a decade, ever since he identified the need for net zero, Professor Allen has championed the idea that carbon capture and storage – whereby carbon dioxide is literally scrubbed out of exhaust gases, or even from the atmosphere itself, and stored safely back underground – should be a licensing condition of continued extraction and use of fossil fuels.

‘It’s perfectly possible to remove CO2 from both flue gases and the atmosphere,’ he assures. ‘It has been proven to work. But no one has the incentive to do it on any scale.’

It’s perfectly possible to remove CO2 from both flue gases and the atmosphere...It has been proven to work. But no one has the incentive to do it on any scale

Professor Allen

It would come with a cost, of course, he says, but it can be done: stopping fossil fuels from causing global warming by taking the CO2 they produce back out of the atmosphere ‘would add about 50p to the cost of producing a litre of petrol’.

He says, without a flourish, but with a sobering thought, ‘That would be the end of climate change…but without it, we won’t get to net zero.’

It sounds so easy, because it is, Professor Allen adds cheerily, unaware of the shock his comments would induce in many people around the world. As if in response, Professor Allen explains, ‘That’s how much it would cost, if the carbon industry [oil companies, mine owners etc] were required to pay for carbon removal and clean-up.’

Stopping fossil fuels from causing global warming by taking the CO2 they produce back out of the atmosphere ‘would add about 50p to the cost of producing a litre of petrol'

Professor Allen

He adds, ‘They’ve got so much money; they don’t know what to do with it. But it would add to the cost of producing fossil fuels, which is a lot to ask in the current situation [with oil prices at record highs].

‘But we can ramp it up over the next 30 years, and over time, people would adjust and buy cars which offered better fuel consumption.’

Without it, we will not meet our climate goals and global temperatures will keep rising past 1.5 degrees. ‘Someone, somewhere, will still be using fossil fuels past 2050.’

It is no secret, the professor says, that a big part of his role for the last few years has been as policy advocate, based on the science. He has been everywhere and told everyone, he says: politicians, business leaders, insurers, environmentalists. And he is clearly astonished at their refusal to take action. Does he think, perhaps, they do not believe in climate change?

‘Oh no, most people recognise there is climate change, and that fossil fuel emissions are the primary cause,’ he maintains. Then why don’t they do as you suggest?

Some people like to belittle the role of carbon capture and insist we should stop using fossil fuels entirely, do it all with renewables. But this won’t happen everywhere, and it can’t happen in time

Professor Allen

He points out, ‘Some people like to belittle the role of carbon capture and insist we should stop using fossil fuels entirely, do it all with renewables. But this won’t happen everywhere, and it can’t happen in time. If you think of it like a product, then it is obvious what we need to do: get rid of the CO2 that fossil fuels generate. They could have improved air quality in the 1970s by reducing traffic, but it was a lot more effective just to take the lead out of the petrol. Of course, there is the problem of trust: the fossil fuel industry hasn’t exactly done itself any favours, so a solution that involves them cleaning up after themselves worries people. But the industry has the capacity to do it – and surely it’s better that they clean up imperfectly than no one cleans up at all.’

Professor Allen adds, ‘Everyone tells me “good idea, but…”’

Everyone has a different reason for not wanting to implement it yet.  ‘But, if Britain imposed regulations to make the polluter clean up [requiring disposal of CO2], it … would be an easily portable policy, which could be copied elsewhere. Much easier than assessing other countries' climate policies to determine if they are 'as ambitious' as ours.'

But what if other countries did not follow a British lead? Would that put the UK at a competitive disadvantage, compared with other developed nations, who could take advantage of higher transport costs here?

‘The cost would be negligible to start with, as we progressively ramp up the fraction of CO2 stored over the next 30 years. But in the end, any climate solution has to be effectively global. The world needs energy – that is crystal clear at the moment. Fossil fuels, particularly for countries who own them, will remain a very, very attractive source. But no one wants to say that they fund dirty industries when there is a readily available alternative,’ he says plainly. ‘So we just need to make sure there is a way of using fossil fuels that does not cause global warming.'

It is possible, particularly at the moment, to think of some countries which may not be too worried about their public image. ‘But that is where globalization helps. By 2050, we just shouldn’t be buying goods, or goods made with goods, that still cause global warming. No international company wants to stuck with customers in the old, dirty world.’

‘Of course, we also need to reduce our dependence on fossil fuels, for all sorts of really obvious reasons right now: but we still have to make sure that whatever fossil fuels are still used, they are used safely, without causing climate change.’

The problem with this “transformation or bust” narrative, Professor Allen insists, is many people find it threatening and 'it isn’t obviously true'

In the build-up to COP27 in Egypt, we are hearing increasingly desperate warnings about the costs of climate inaction. Last week, UNEP, his old employer, released its annual Emissions Gap Report, with the headline, ‘Only an urgent, system-wide transformation can avoid climate disaster.’

The problem with this “transformation or bust” narrative, Professor Allen insists, is many people find it threatening and 'it isn’t obviously true'. Adding 50p to the cost of a litre of petrol over the next 30 years, he argues – the cost of stopping fossil fuels from causing global warming by cleaning up the carbon dioxide they generate, and less than petrol prices increased between 2004 and 2019 – would undoubtedly bring changes.

'Ask anyone, including those employed in the fossil fuel industry, would they like the cost of fossil fuels to go up like that, and they’ll say no. Ask them whether they would cope with such a rise, phased in predictably over a generation, and they’re mystified: of course they would.'  

Professor Allen’s approach offers an infectiously-hopeful, not to say scientific, path through the increasingly hopeless climate narrative

He could well spend the next few years repeating this message, as he has been doing for the last few decades – until someone realises Professor Allen’s approach offers an infectiously-hopeful, not to say scientific, path through the increasingly hopeless climate narrative.

By Sarah Whitebloom