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Oxford Net Zero: Understanding What It Will Take to Halt Global Warming

Nov 25, 2020

With Joe Biden in the White House, 2021 could be the year the world embraces net zero: but universities still have work to do to turn a trendy phrase into meaningful action to halt the climate crisis.

If it weren’t for Covid-19, the annual UN climate conference would be taking place right now in Glasgow. As it is, that meeting has been rescheduled to November 2021 and the UK government, as host, still seems to be casting around for the big theme. But with the US joining all other G7 countries aiming for net zero emissions or Xi Jinping committing China to carbon neutrality by 2060, hundreds of companies joining the ‘Race to Zero’, the answer is increasingly obvious: this is the Year of Net Zero.

Is this the beginning of the end of the climate crisis? Let’s hope it is at least the end of an agonisingly protracted beginning. But to stick with the Churchillian analogies, wars aren’t won by evacuations, and global warming won’t stop with declarations – particularly declarations about an ill-defined target 30 years off in the future. How many of the countries, companies and cities committing to net zero have thought through exactly what it means beyond an ambitious-sounding climate goal?

That said, in these gloom-ridden times, we must remind ourselves there is a lot to celebrate here. Only 15 years ago, I gave a talk highlighting the need to limit cumulative carbon emissions – and hence achieve net zero to stop global warming – at “Stabilisation 2005”, a workshop convened by Tony Blair.

At that time, the goals of climate policy were very different. The clue is in the workshop name: stabilisation of greenhouse gas concentrations at a level that would prevent dangerous climate change, and contraction and convergence of emissions per person to whatever rate that implied.

The problem in 2005 was that climate science was, and still is, struggling to pin down a “safe” stabilisation concentration. It turns out that the long-term warming resulting from a given concentration of carbon dioxide in the air is worryingly uncertain. But much more certain is the response to cumulative emissions. Every tonne of carbon dioxide we emit causes approximately the same amount of warming as every other tonne, unless it is scrubbed out again. Which means the long-term sustainable rate of net emissions of carbon dioxide that we have to contract and converge to is… zero.

The world looks very different now, and while everyone tends to focus on historically high- emitting western countries, most of the credit for the change should go elsewhere. For the UK to increase the ambition of our climate targets from the 80% reduction agreed in 2008 to 100% now was a big deal, but in a sense it was more of the same (although that final 20% will prove particularly interesting). For China and India to accept, in the Paris Agreement, that the 250-year-old practice of dumping carbon dioxide into the atmosphere was going to have to come to an end, only a few short decades after they had joined the ranks of carbon-dioxide-dumpers, was absolutely transformative.

But there is still a lot to be done, including by the world’s universities helping everyone understand what net zero means, and what it will take to get there. The net in net zero is an acknowledgment that we need to stop global warming before the world stops generating greenhouse gas emissions. But how much of the work should it do? And which emissions should we be netting out? Is planting trees to enable your customers to “drive carbon neutral”, for example, the best use of the limited carbon capacity of the biosphere? Oxford Net Zero is a four-year initiative, launching today, to help the world achieve net zero: we will focus not on the immediate challenge of bending the emissions curve downwards, important though that is, but on the end-game. The last 20% of emissions that arise from activities so valuable that no conceivable carbon price will squeeze them out. How we balance, and govern, the drive to reduce emissions with the inevitable need to take carbon dioxide back out of the atmosphere. It’s a many-faceted challenge, and this support from the Strategic Research Fund is allowing us to bring together colleagues from Geography, Earth Sciences, Zoology and Plant Sciences, Anthropology, Physics, Law, Government and Business to address it in a coherent way.

Many of the issues we’ll be thinking about will be coming close to home, as the University is also stepping up with an ambitious new Sustainability Strategy, currently out for consultation: make sure to have your say: https://sustainability.admin.ox.ac.uk/consultation

Above all, Oxford Net Zero is about how we balance the needs and interests of different regions of the world today, and between present and future generations, through this great transition. Having played our part in defining this challenge, we now want to step up to help everyone meet it.

Myles Allen

School of Geography and the Environment & Department of Physics, University of Oxford

Director, Oxford Net Zero

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