Future warming increases probability of globally synchronized maize production shocks

Area of Science:

• Agricultural Science
• Climate Science
• Food Security

Background:

• Global food demand is rising, projected to reach 10 billion by 2050.
• Climate warming is expected to decrease crop yields and increase variability.
• Maize is a critical global food staple, making its production vulnerable to climate change.

Purpose of the Study:

• To quantify the impact of global warming on maize yield variability.
• To assess changes in yield variability in major maize-producing and exporting countries.
• To project the risk of simultaneous production losses under different warming scenarios.

Main Methods:

• Utilized global maize production and climate variability datasets.
• Incorporated future temperature projections for 2 °C and 4 °C warming scenarios.
• Analyzed changes in the coefficient of variation (CV) of maize yields.

Main Results:

• Maize yield variability (CV) is projected to increase globally with rising temperatures.
• Absent heat tolerance improvements, mean yields decrease and variability increases.
• The probability of simultaneous >10% production loss in top exporting countries rises from near zero to 7% (2 °C) and 86% (4 °C).

Conclusions:

• Projected warming will lead to increased instability in global grain trade and prices.
• Extreme poverty populations are most vulnerable to food price spikes.
• Urgent investment in breeding for crop heat tolerance is essential.