Unless we step up our efforts to embrace bioenergy and other renewables in favor of fossil fuels, we will miss our best chance to do so at a large scale as climate change is bound to decrease crop yields, thereby reducing the availability of biomass feedstocks, according to an international team of researchers from York University in the United Kingdom and Funan University in China.
Reductions in food production because of a changing climate will also lead to expansions in cropland, which will increase greenhouse gas emissions from land use further still, worsening climate change.
The researchers reached this conclusion after modeling how rising temperatures, atmospheric CO2 concentration, nitrogen fertilization intensity and precipitation would affect crop yields worldwide. They found that if a switch to bioenergy with carbon capture and storage (BECCS) is delayed to the latter half of the century, biomass production would be largely reduced by climate change.
That is concerning as climate scientists have stressed the importance of upscaling BECCS worldwide to keep warming under 2 degrees Celsius. Yet if BECCS is delayed from 2040 to 2060, reduced yields of agricultural residue for biomass technologies would decrease its capacity, the new research indicates.
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As a result, global warming would increase from 1.7 degrees Celsius to 3.7 degrees Celsius by 2200 while global average daily crop calories per capita would decline from 2.1 million calories to 1.5 million calories.
In this scenario the scale of food production would need to increase by 80% from 2019 levels in order to avoid severe shortages in many parts of the developing world which will be worst affected by climate change.
“Biomass fuels and feedstocks offer a renewable source of energy and a viable alternative to petrochemicals, but the results of our study act as a stark warning about how climate change will put their availability at risk if we continue to allow global temperatures to rise,” explains Prof. James Clark, a scientist at York University’s Department of Chemistry who was a coauthor of the study.
“There is a tipping point where climate change will severely impede our ability to mitigate against its worst effects,” Clarks adds. “Biomass with carbon capture and storage including the manufacture of bio-based chemicals must be used now if we are to maximize its advantage.”
However, we still have a chance to act to avert excessive warming and attendant food shortages.
“If negative-carbon mitigation technologies relying on biomass could be widely deployed in the short term, there is still hope that we can alleviate global warming and a global food crisis,” Clark stresses.
