Science calls for urgent implementation of bioenergy-based technologies against climate change

The latest report of the Intergovernmental Panel on Climate Change (IPCC) considers bioenergy with carbon capture and storage (BECCS) a key process to reduce global warming. However, in the article Delayed use of bioenergy crops might threaten climate and food security published in the journal Nature, an international group of researchers warn that if BECCS technology is not implemented urgently, by 2040, it won't be able to capture and store the carbon needed to drastically reduce greenhouse gases. The study stresses that if the implementation of BECCS technology is delayed until the second half of the 21st century, the detrimental effects of climate change (drought and heat waves) will limit agricultural yields and, as a consequence, the production of biomass (resulting organic matter), the very feedstock essential for bioenergy production, will be reduced. Therefore, BECCS will no longer have as much capacity to capture and store carbon. The study affirms that if they are implemented late, it won't be possible to ensure that in the year 2200 the objective of the Paris Agreement of limiting global warming to less than 2°C with respect to pre-industrial levels will be achieved.

If bioenergy technologies with carbon capture and storage are not implemented until the second half of the 21st century, the Paris Agreement goals won't be met even in 2200. 

The study further adds that in the event that BECCS is implemented late, this lower crop productivity could force an expansion of agricultural land, increased fertiliser use and, as a consequence, higher greenhouse gas emissions, further accelerating climate change. This would produce a feedback loop on global warming that has so far not been contemplated.

In the work published in Nature, led by Prof. Rong Wang from Fudan University (Shanghai, China), the CREAF and CSIC researcher Josep Peñuelas and the CREAF researcher Jordi Sardans have participated. Their conclusion is forceful. A context that endangers climate stability and threatens world food security. "Our findings reinforce the urgency for early mitigation, to avoid irreversible climate change and severe food crises, unless other negative emissions technologies become available in the near future to compensate for reduced BECCS capacity", according to researcher Jordi Sardans.

"If we delay bioenergy technology with carbon capture and storage until 2040 or 2060, in the year 2200 global warming will rise between 1.7 and 3.7°C because we will have less of the necessary biomass"

JOSEP PEÑUELAS, CREAF researcher.

A larger food gap

Add to this, the sustained demand for food in the world, and global warming is once again on the rise. The need for food will lead us to expand agricultural land, to intensify its fertilization with nitrogen, to change the uses of forests and to strengthen the export of food such as wheat and rice, all activities related to the emission of greenhouse gases. greenhouse. To help reverse the situation, the research team insists on implementing BECCS technologies before 2040, unless other negative emission technologies become available in the near future.

If the application of bioenergy with carbon capture and storage is delayed to 2060, by 2100 the current 81 developing countries with a positive food gap will have increased to 90. 

While the relationship between climate change and food supply varies from region to region, the study concludes that if the implementation of BECCS is delayed to 2060, the number of developing countries with a positive food gap will increase from 81 to 90 by 2100 (calories per capita below the malnutrition level of 1.5 Mcal d-1). It has also been calculated that exporting wheat, rice and maize to reduce hunger from North America, Europe and China to less developed areas would require export levels between 2 and 80 times higher than current levels depending on the region and crop. In other words, in some cases too large to be plausible.

Bioenergy with carbon capture and storage

BECCS technology involves extracting bioenergy from biomass into useful forms (electricity, heat, biofuel etc.) and then capturing and storing the carbon by removing it from the atmosphere. Some of the carbon in biomass is converted to carbon dioxide (CO2), which can be stored by geological sequestration or land application. This makes it possible to remove CO2 from the atmosphere and reduce the greenhouse effect of this gas and, for this reason, it is called a negative emissions technology.

Reference:

Xu, S., Wang, R., Gasser, T. et al. Delayed use of bioenergy crops might threaten climate and food security. Nature 609, 299–306 (2022).

doi: https://doi.org/10.1038/s41586-022-05055-8