In a strange twist of policy fate, global decarbonization may be stalled by ….global decarbonization. And in the mix, agriculture could become an unfortunate co-casualty.
The issue at hand: sulfur, which is used in the form of sulfuric acid in the production of phosphorus fertilizer. It also is employed in the extraction of rare metals from ores such as nickel and cobalt, which are used to manufacture the high-performance, lithium-ion batteries that power electric vehicles.
A recent study by the Institute of British Geographers and University of College London (UCL) examined the shift in sulfur supplies and the potential impact of sulfur shortages.
Currently, more than 80% of the global sulfur supply comes from the desulfurization of crude oil and natural gas. Sulfur has been removed from these fossil fuels for decades, to reduce sulfur dioxide gas emissions that cause acid rain.
But as the world moves away from fossil fuels, the ready supply of sulfur also is expected to wane – at the same time demand for it is predicted to go up. The British researchers estimated that by 2040, sulfuric acid demand will rise from 246 to 400 million metric tonnes annually. The predicted concurrent shortfall: between 100 and 320 million metric tonnes, or between 40 and 130% of current supplies, depending on how rapidly global decarbonization occurs.
The sulfur supply imbalance may be lessened by a dog-chases-tail scenario in which less available sulfur means fewer lithium-ion batteries can be made, which would perpetuate the employment of fossil fuels, which would continue to yield sulfur.
Still, it’s a complicated situation that the researchers say deserves immediate attention.
Lead author of the study, Mark Maslin, said global sulfur shortages have occurred before. But rather than brief supply chain blips, this situation is different in that it would be the result of a wholescale shift away from fossil fuel processing.
“What we’re predicting is that as supplies of this cheap, plentiful, and easily accessible form of sulfur dry up, demand may be met by a massive increase in direct mining of sulfur,” said Maslin.
“This, by contrast, will be dirty, toxic, destructive, and expensive.”
They suggested one way to ease the burden on agriculture would be to invest in technology to recycle phosphorus in wastewater and channel that supply to fertilizer production. Such production shifts need to be mobilized rapidly, they argue, to prevent a sulfur supply gap that could trap agriculture in a costly tug-of-war with battery manufacturing.
Simon Day, co-author of the study, said, “Our concern is that the dwindling supply could lead to a transition period when green tech outbids the fertilizer industry for the limited, more expensive sulfur supply, creating an issue with food production, particularly in developing countries.”
