As climate and Earth scientists, we are acutely aware that action on climate change is desperately needed. It is now almost certain that 2024 will not only be the warmest year ever recorded, but also the first year that will be 1.5°C warmer than pre-industrial levels.
The Paris climate agreement pledged to “pursue efforts to limit the temperature increase to 1.5°C”, but that now looks to be a forlorn hope. The effects of climate change increase with the level of global warming, such that every 0.1°C adds to the suffering of those most vulnerable. As recent devastating storms in Spain have shown, those people may be much closer to home than many had assumed.
The sooner we reach net zero emissions, the sooner the global temperature will stop increasing and the effects of climate change will stop worsening. Unfortunately, we are nowhere near net zero. Last year, emissions from the burning of fossil fuels were at an all-time high.
Some would say carbon offsetting offers us a way out. At the University of Exeter we have explored the role of carbon offsets in the university’s very ambitious target of net zero by 2030.
Exeter has made great progress in reducing emissions by switching to suppliers that generate electricity from wind and solar, as well as installing lots of solar panels on campus. However, because we include “scope 3 emissions”, which includes things like travel and embedded carbon in products, the assumption was that carbon offsetting was going to be required.
Carbon offsetting typically involves buying carbon credits. These credits are created when carbon is removed from the atmosphere (such as by planting trees) or more usually when emissions are avoided somewhere else. For example, cutting down and burning a large forest would emit a large amount of carbon dioxide.
If instead this forest is protected, then the managers of the forest can generate carbon credits which can be sold to organisations or individuals to offset the carbon pollution they are creating.
Today, you will find commitments to offset emissions in the climate strategies of governments, small businesses, multinational corporations, international football teams and even famous music bands. It’s an approach to the climate crisis that is supported by many universities, which fully understand the science of climate change.
Unfortunately, carbon offsetting is beset with problems. In too many cases, it’s hard to verify if these credits have actually prevented emissions. And it’s especially hard to verify if they will continue to prevent emissions permanently.
We currently sit on an official University of Exeter panel advising our own university on offsetting, and we have concluded that carbon offsetting should be removed from plans to reach net zero.
This panel was initiated by the university executive board, and comprises internationally recognised environmental and sustainability scientists, physicists, engineers, social scientists and writers, along with students. It includes an IPCC author, IPCC reviewer and those who specialise in clinical advice, the circular economy and industry liaison.
We reviewed the evidence for all types of offsetting. We discussed offsetting with industry professionals and academics from other universities. We also performed some simple thought experiments, based on our knowledge of the Earth system, to consider how fast carbon emissions could be removed from approaches such as tree planting.
We found no evidence that offsetting could make a meaningful contribution to our efforts to get to net zero. Instead, we concluded that offsetting is probably ineffective – and possibly a dangerous distraction as it can lead to inaction on actual emissions reduction. We concluded that efforts should focus on working out how to leave more fossil fuels safely in the ground.
We accept that ditching offsets will blow a large hole in our university’s plan to reach net zero. Given how widespread offsetting has become, we imagine that if other organisations were to do likewise, then their net zero strategies would also be seriously affected. But universities worldwide have a social responsibility to lead by example and to act on the knowledge that their communities have produced.
To that end, we recommend the following courses of action that other universities and potentially all other organisations should now urgently consider.
Following our advice is likely to be uncomfortable for our university, but we hope it will translate into a more thoughtful and honest approach to addressing the climate emergency. If other universities do likewise, it will send a strong signal to business leaders and politicians that meaningful action is not only needed, but possible.
Continuing to stand behind the fallacy that carbon offsetting approaches will get us out of the climate crisis is now untenable.
