Lemnaceae as a resilient crop to improve food security under climate extremes: global warming and post-catastrophic cooling scenarios

Background: Future impacts of rising temperatures and extreme weather events on agriculture are expected to be severe, potentially resulting in a 25% reduction in global crop yields by 2050. As a risk multiplier, global warming also exacerbates existing conflicts over natural resources. In the event of large-scale conflicts like nuclear war, food production could suffer significantly, potentially declining by 90% in global average calorie production due to the resulting cold and dark weather conditions. Lemnaceae (commonly known as ‘duckweed’) is a family of prolific aquatic plants and a high-protein food source. It is capable of growing in extreme hot or cold conditions, where conventional crops struggle. This study investigates the effects of both global warming and post-nuclear war cooling on duckweed growing seasons and biomass production. A plant growth model was coupled with climate data to predict annual duckweed yields across 20 locations worldwide, considering two global warming scenarios: (1) an optimistic sustainable pathway with low greenhouse gas emissions and (2) a fossil fuel-dominated pathway with medium to high greenhouse gas emissions. We also examined three post-nuclear war cases with different atmospheric carbon injections. Results: In low-latitude equatorial regions, global warming and the low-emission nuclear war case had minimal impact on duckweed yields (less than 6% change from baseline), whereas higher latitudes experienced yield increases (up to 90%) with global warming. The high-emission nuclear war cases showed a significant reduction in yields, but equatorial regions could still produce 19–20 metric ton/ha of duckweed annually. Conclusions: The findings from this work substantiate the versatility of duckweed to improve global food security under both global warming and post-catastrophic cooling scenarios.