Solar geoengineering can alleviate climate change pressures on crop yields

Area of Science:

• Climate science
• Agricultural science
• Environmental science

Background:

• Climate change impacts food security.
• Solar geoengineering (SG) and CO2 emissions reduction are potential climate change mitigation strategies.
• Their comparative effects on crop yields are not fully understood.

Purpose of the Study:

• To analyze crop yield responses to three SG technologies and CO2 emissions reduction.
• To compare these impacts under similar radiative forcing and land use assumptions.
• To investigate the drivers of yield changes, including radiation, moisture, and CO2.

Main Methods:

• Utilized an advanced crop model integrated within an Earth system model.
• Simulated yield responses for six major crops.
• Assessed impacts of different radiative forcing reduction methods.

Main Results:

• All four methods (3 SGs, 1 emissions reduction) provided significant cooling benefits for crop yields.
• Global crop yields increased by ~10% under the three SG scenarios.
• Global crop yields decreased by 5% under emissions reduction, mainly due to reduced CO2 fertilization.
• Relative humidity was the dominant hydrological factor for rainfed crops.
• Net insolation effects were negligible across all SG scenarios.

Conclusions:

• Solar geoengineering and emissions reduction have contrasting effects on global crop yields.
• SG shows potential for increasing yields, while emissions reduction may decrease them.
• Understanding these complex interactions is crucial for future food security assessments.