CO2 removal is essential to achieving net zero

Oct 13, 2021

By Dr Steve Smith, originally published by University of Oxford news on 23 September 2021. Photo: Climeworks. The Orca plant in Iceland.

Dr Steve Smith is executive director of the Oxford Net Zero Initiative and the CO2RE hub, which is focussed on greenhouse gas removal.

Cleaning up waste may not sound like the most exciting, cutting-edge area of innovation. But, in the context of climate action, it is an entirely accurate description.

Carbon dioxide (CO2) is the waste emitted from fossil fuels, and much of the focus about combatting climate change has been on cutting emissions. Increasingly, though, there is also role for cleaning up the waste that is already present – quite literally removing CO2 from the air.

We have many well-known, cost-effective ways to avoid emissions at source, from renewable power to electric transport. But there are some activities – such as agriculture and aviation – for which it is virtually impossible to eliminate all emissions, at least in the foreseeable future. In the waste management business, there is a well-established hierarchy:  reduce, reuse, recycle, recover, dispose. The same can apply to the climate. Reducing the production of waste CO2 is the priority, but the story should not stop there.

CO2 removal is critical to reaching net zero emissions. And it opens up the option of going “net negative”, which is needed in many pathways that meet the Paris Agreement. According to the government’s advisers, the UK’s net zero target will involve directly removing 100 million tonnes of CO2 from the atmosphere each year, by 2050. (This is in addition to eliminating almost all emissions from electricity, surface transport, manufacturing, and heating and cooling buildings.)

And 100 million tonnes is not a small amount of waste. It is equivalent to all the current emissions from surface transport, our largest-emitting sector. It means creating a new removals industry within 30 years. Much of this would be in rural areas, where land can be restored, and on the coasts and the North Sea where CO2 can be piped and stored – areas which could do with new opportunities as the industries of the past decline.

Interest in removals is rising rapidly in response to this urgent need. At Oxford, we are leading a new UKRI-backed Greenhouse Gas Removal Hub.

Our aims are three-fold:

  • To identify and evaluate different removal techniques, sifting the ineffective ones and supporting those with promise;
  • To understand and provide solutions for the economic, social and political factors which influence deployment; and
  • To foster a bigger, more diverse and more capable community of removal research and practice in the UK.

We are working closely with five demonstration projects around the country, each looking at new, improved ways to capture and store carbon on land – for example through trees, biochar and peatlands. Research shows that working with nature has significant potential. But these can only scale-up so far, and the carbon can be re-released if land managers change their practices or fires and pests invade.

Other technologies are starting to emerge which could permanently store greater amounts of CO2. Just this month in Iceland, operation commenced at a facility to separate CO2 from air using fans, chemicals and heat, and then mineralise it in volcanic rocks. The largest project of its kind, at 4,000 tonnes per year, this technology has a long way to go before operating at scale. But it is an exciting step forward.

In North Yorkshire, the UK’s largest power station, Drax, is trialling the capture of CO2 from its bio-powered generators. It hopes to connect to a pipeline which would send the CO2 (taken out of the air by the biomass as it grows) to be stored under the North Sea. If realised, it could capture 8 million tonnes per year.

While a range of different techniques are emerging, they will not develop unless businesses and land managers see some kind of benefit to using them.

Current incentives are scant. Many carbon pricing schemes (such as the EU and UK Emissions Trading Systems) only offer a price for emission reduction, not removal. So there is scope for innovation in policy as well as technology.

Oxford researchers are making strides on this too, developing ideas such as a “carbon takeback obligation” on emitters, or financing removals through “debt” repayments on the “loan” of carbon to the atmosphere.

New ideas are not just coming from the UK. In the US, leading tech companies such as MicrosoftStripe and Shopify are putting voluntary funds into early-stage removal technology alongside the federal government.

The UK has the opportunity to become a testbed for removals policy and governance. Ahead of hosting the COP26 negotiations in November, the government is expected to set out its plan for how the UK will achieve net zero emissions by 2050. And within that, for the first time, will be a strategy for scaling up greenhouse gas removal.

Greenhouse gas removal is here and growing. The question is not whether to do it, but how to do it sustainably, equitably and rapidly, on the road to net zero and beyond. There are a fascinating few years ahead, especially in the waste disposal business.

Read more about Oxford’s climate research and action at True Planet.

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