Plant-based diet can help unlock technology to harness huge CO2 removal
Bioenergy with carbon capture and storage (BECCS) is a promising method for removing carbon dioxide (CO2) from the atmosphere and simultaneously generating energy. Yet this method is controversial, as it may require a great deal of land and water. Researchers at Leiden University have now proposed a solution: if people switch to a predominantly plant-based diet, the agricultural land that this releases can be used to boost climate change mitigation.
The idea of BECCS was first proposed around 20 years ago and it seemed to be a magical solution for the problem of greenhouse gases: growing crops removes CO2 from the air; these crops can then be used to generate energy, for example through combustion, while the resulting CO2 is captured and permanently stored in geological formations. BECCS can therefore remove CO2 from the atmosphere to slow down global warming and even help reverse it. ‘The idea gained so much popularity over the years that scientists have widely included BECCS in their proposed climate-mitigation plans – many of which heavily relied on it’, says researcher Oscar Rueda.
Sustainability
In recent years, however, serious questions have been raised about the sustainability of BECCS: as growing crops for the biomass needed requires a great deal of agricultural land and water, large-scale use of BECCS can threaten biodiversity, food security and water supplies. The research conducted at the Institute of Environmental Sciences (CML) shows that these problems can largely be overcome by switching to a diet with more plant-based products. This will release large areas of grazing and arable land and significant quantities of water, which can then be used for growing biomass crops.
High energy output and CO2 removal
‘You only need to use a fraction of the released land for BECCS and huge amounts of energy can be generated and CO2 removed from the air’, says Rueda. Replacing 50 per cent of animal products by 2050 could release enough land for BECCS to generate the same amount of energy per year as coal-fired power stations today. Moreover, the amount of CO2 removed from the air would be nearly as much as the amount currently emitted by those power stations.
The way land is used at the moment is very inefficient. Much of our agricultural land is used to feed animals, which is more inefficient than directly using it for food for people. ‘We want to show countries that this is an excellent opportunity’, says Rueda. ‘By doing this, you can tap vast energy potentials. You can spur your economy and at the same time improve the health of your population.
‘BECCS can play an important role in accelerating global emission reductions. By removing CO2 from the atmosphere, it can help avoid exceeding the critical 1.5°C limit. And by producing energy, it can also help speed up the phasing out of fossil fuels’, Rueda continues, before adding, ‘BECCS faces important sustainability challenges, and we show that by adopting more sustainable diets, we can overcome the main issues to harness its benefits more safely.’
The article 'A protein transition can free up land to tap vast energy and negative emission potentials' can be read in One Earth.
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