Chart of the Day: How much land would carbon capture and storage really require?

A report by Oxfam has revealed that millions of hectares of land would be needed to meet carbon sequestration targets.

With the COP26 international climate conference just months away, net zero targets are proliferating.

Net zero targets allow governments and businesses to continue emitting carbon into the atmosphere so long as these emissions are offset through carbon capture, such as planting trees or bioenergy crops.

But a new report by Oxfam has revealed the amount of land that would need to be repurposed to feed these carbon capture schemes. The charity estimates that meeting the carbon sequestration targets of just four energy companies would require between 50 and 70 million hectares, or two to three times the entire land area of the UK.

If the rest of the fossil fuel industry were to adopt similar plans, the total land area required could be as much as 500 million hectares, or half the size of China.

Currently considered the most promising method of carbon sequestration by the UN’s Intergovernmental Panel on Climate Change (IPCC), bioenergy carbon capture and storage (BECCS) sees crops grown and then burned for energy generation, with the resulting carbon captured and stored.

The IPCC estimates that BECCS could remove 11 gigatonnes of CO2 equivalents each year. However, Oxfam’s analysis found that this could require devoting an area twice the size of India to growing bioenergy crops, which would use 25-46 per cent of global cropland and plunge an estimated 150 million people into food insecurity.

“Land is a finite and precious resource that millions of small-scale farmers and indigenous people depend upon to feed their families,” said Oxfam’s CEO Dhananjayan Sriskandarajah.

“Nature and land-based carbon removal schemes are an important part of the mix to lower emissions but more caution is needed to ensure good stewardship that doesn’t threaten food security.”

Similar to BECCS, afforestation and reforestation also require vast tracts of land to be solely devoted to carbon capture. While the IPCC estimates that the three methods could remove as much as 30 gigatonnes of CO2 equivalents each year, Oxfam’s analysis found that this would require 1.62bn hectares – an area the size of Russia.

Estimates suggest that large-scale afforestation could increase food prices by 80 per cent by 2050, pushing millions into hunger.

Other land-based carbon capture schemes, such as agroforestry, do not compete with crops and could even improve food security.

The report estimates that 23 gigatonnes of CO2 equivalents could be removed annually through a mixture of such schemes. However, without proper regulation the commodification of carbon is likely to favour more high-intensity schemes such as BECCS and afforestation.