HomeLow carbon futureWe have to take CO2 out of the atmosphere but how it’s done matters

We have to take CO2 out of the atmosphere but how it’s done matters

This post is by Jim Elliott, senior policy adviser and Caterina Brandmayr, head of climate policy at Green Alliance. 

Last week Carbon Market Watch questioned the credibility of claims that the football World Cup in Qatar would be carbon neutral. Even without detailed analysis, the idea that building and running eight air conditioned stadiums in the desert could be done in a carbon neutral way may raise eyebrows. Qatari plans for the World Cup appear to rely on a large amount of offsetting, including sequestering carbon in a new large scale tree nursery.

But there is a limit to how much carbon we can take from the atmosphere. So, what makes a good carbon removal, how much carbon can we reasonably expect to pull out of the air in a sustainable way and how do we avoid it undermining efforts to cut emissions across the economy? These are some of the questions we are currently working to answer.

There’s little doubt that, to reach net zero and prevent the worst impacts of climate change, alongside rapid and deep emissions cuts across the economy, we will need to remove CO2 from the atmosphere. Sectors like aviation and agriculture are, in fact, unlikely to cut their emissions to zero by 2050. And, globally, we need to get to net negative emissions, at least temporarily, to bring CO2 concentrations back to safe levels.

A range of options will play a part in greenhouse gas removal, from natural sequestration in vegetation and soils to so called engineered solutions, such as Bioenergy with Carbon Capture and Storage (BECCS) and Direct Air Carbon Capture and Storage (DACCS). These technologies are used to capture CO2 from biomass or from the atmosphere and pump it into underground reservoirs.

The right scale and mix will be important to avoid the downsides
Natural sequestration in well managed vegetation and soil is available now: it’s inexpensive and, if done well, it is good for nature, creating conditions for greater biodiversity. But it can be slow (trees take decades to grow) and there are issues of permanence because carbon stored in nature fluctuates over time, for example it can be released due to fire or disease in trees.

Engineered solutions may be able to store carbon more quickly and over longer time, but they are in their infancy and are expected to be significantly more expensive than nature-based options. There are also concerns that extensive deployment of BECCS could put pressure on land, potentially driving greater deforestation globally and undermining food production, and that it could create a ‘carbon debt’, given carbon in the atmosphere is only reduced after the biomass replacing the one harvested for BECCS regrows.

How and where greenhouse gas removals happen will be important to make sure they are sustainable, and that they truly deliver negative emissions. Planting the right tree in the right place will be good for nature and the climate. Making use of agriculture residues and wastes as a biomass feedstock instead of specially grown crops or trees could avoid the negative land use change and carbon impacts of BECCS, assuming these wastes were genuinely unavoidable. Energy crops could also be grown in a way that benefits nature as well as removing carbon.

But the scale at which these solutions are delivered is equally crucial, as carbon removals rely on land and energy, both of which are already under pressure. At worst, for example, large scale BECCS could see three million hectares, equivalent to 17 per cent of the UK’s agricultural area, dedicated to growing biomass. This is likely to displace food production and reduce space for restoring semi-natural habitats like woodland, with limited or no prospect of reversing biodiversity decline and potentially also increasing pressure on land abroad.

Emissions reduction should therefore be prioritised to limit the overall need for removals and minimise their negative impacts. The government should also identify the scale and combination of carbon removal solutions that will have the best outcomes for society and the environment, factoring them into policy.

Business as usual will undermine successful carbon removals
While the net zero strategy outlines indicative sectoral pathways for decarbonisation, it doesn’t set sector specific emissions targets or require businesses to cut emissions in line with their sector’s pathway. And it doesn’t put any limits on business use of greenhouse gas removals to get to net zero. This, combined with poor understanding of their limitations, and the current availability of cheap options like tree planting, means big polluters are relying too much on offsetting, while simultaneously failing to decarbonise their operations.

For example, analysis of the claims of 25 large corporations, carried out by the New Climate Institute and Carbon Market Watch earlier this year, showed that their plans only involve direct emissions reductions of about 40 per cent, rather than down to zero emissions, relying on offsetting for the remainder. If businesses globally were to follow suit, the amount of greenhouse gas removals needed is very unlikely to be achieved without significant impacts on nature and the global food system. And, if the quality of carbon credits isn’t sound, there is a risk the net zero target will be missed, with devastating consequences for the climate.

How costs are distributed also matters. Without clear rules around which sectors can access carbon removals, major polluters, including oil and gas and aviation, have moved early in the voluntary carbon offset market and invested in cheaper options like tree planting (with concerns around corporations buying up farmland). While this reduces their reliance on more expensive engineered removals in the future, it means less wealthy sectors with residual emissions in 2050, like agriculture, will have to pay for costly BECCS and DACCS. Or, more likely, it will be down to taxpayers to foot the bill.

Stronger governance is needed
Leaving greenhouse gas removals purely to the market risks failing society and the environment. As also highlighted by the Environmental Audit Committee, and the government’s task and finish group on monitoring, reporting and verification of greenhouse gas removals, stronger governance is needed.

Upcoming decisions around new business models and on including greenhouse gas removals in the UK emissions trading scheme will be important in the development of this new industry. But, as we will explore in more detail in our forthcoming report, to address all the risks effectively government needs to go beyond that.

Clear rules around how and when carbon removals should be used by different sectors, setting requirements for business claims about carbon neutrality and net zero strategies, and more explicit environmental and social considerations in standards and policy, are all essential if the UK is to be at the forefront of this new industry, an industry which, while controversial, will nevertheless be vital in the global fight against climate change.