Clark, Brendan, Alan Robock, Lili Xia,
Sam S.
Rabin, Jose R. Guarin, and Jonas Jägermeyr, 2025: Stratospheric aerosol climate
intervention
could reduce crop nutritional value.
Env.
Res. Lett., 20, 114083,
doi:10.1088/1748-9326/ae1151.
https://iopscience.iop.org/article/10.1088/1748-9326/ae1151
Abstract
The deliberate addition of sulfur dioxide in the stratosphere to
form reflective sulfate aerosols, reflect sunlight, and reduce
surface temperatures is increasingly being considered as an option
for minimizing the impacts of climate change. This strategy would
create an unprecedented climate where the relationship between
surface temperature and carbon dioxide concentration is decoupled.
The implications of stratospheric aerosol intervention (SAI) for
global crop protein concentrations have not yet been explored. While
elevated CO2 concentrations are expected to reduce crop protein,
higher temperatures may increase crop protein concentrations. Here
we report changes of maize, rice, soybean, and wheat protein
concentrations under a medium emissions climate change scenario and
a SAI scenario to maintain global average temperatures at 1.5 °C
above preindustrial levels, as simulated by three global gridded
crop models. We show that using SAI to offset surface temperature
increases would create decreases in the global protein
concentrations of maize and rice, with minimal impact on wheat and
soybean. Some already protein-deficient and malnourished nations
that rely heavily on these crops to meet protein demands would show
large decreases in protein intake under SAI with the current diet
pattern, which could exacerbate their nutrient scarcity. The range
of results between crop models highlights the need for a more
comprehensive analysis using additional crop models, climate models,
a broader range of climate intervention scenarios, and advancements
in crop models to better represent protein responses to climate
changes.