Impact of Climate Change on Global Food Production and Sustainable Development Goals

Introduction

Climate change poses significant challenges to global food production, raising critical questions about its effects on crop yields and the capacity to feed a growing population in a warmer world. This report examines the future impacts of climate change on agriculture, emphasizing the implications for achieving the United Nations Sustainable Development Goals (SDGs), particularly SDG 2 (Zero Hunger), SDG 13 (Climate Action), and SDG 1 (No Poverty).

Mechanisms of Climate Change Impact on Agriculture

1. Carbon Fertilization: Elevated atmospheric CO₂ levels can enhance plant growth, especially for C3 crops like wheat and rice, while C4 crops such as maize, millet, and sorghum benefit minimally except under drought conditions.
2. Temperature Changes: Crop yields respond variably to temperature increases. Temperate regions may experience yield improvements due to temperatures moving closer to optimal growing conditions, whereas tropical and subtropical regions face yield declines as temperatures exceed optimal thresholds.
3. Water Availability: Changes in water stress, including droughts and flooding, significantly affect crop productivity, with increased frequency and intensity of such events threatening yields.

Global Crop Yield Projections Under Climate Change

The overall impact on crop yields results from the interaction of carbon fertilization, temperature changes, and water availability. Key findings include:

• Maize: Projected to decline globally with warming; under low warming (RCP2.6), yields may decrease by ~6%, and under high warming (RCP8.5), by up to 24%. This decline threatens food security in major maize-producing regions such as the United States, China, South America, and Sub-Saharan Africa.
• Wheat: Expected to benefit from carbon fertilization, with potential yield increases of up to 18% under extreme warming scenarios, particularly in temperate regions like Europe and northern India.
• Rice and Soybeans: Exhibit smaller climate impacts, with temperature-related yield declines largely offset by carbon fertilization. Regional variations exist, with some areas experiencing modest yield increases.

Regional Variability in Crop Yield Changes

Climate change impacts on crop yields vary significantly by latitude and region:

• Temperate and high-latitude regions may see yield increases despite extreme weather events.
• Tropical and subtropical regions, where many staple crops are grown near their optimal temperature, face substantial yield declines and have lower adaptive capacity.
• Maize yields are particularly vulnerable in regions between 60°N and 30°S, affecting food security in many developing countries.

Implications for Food Security and SDGs

The unequal distribution of climate change impacts exacerbates existing inequalities, with the poorest and most food-insecure populations—often reliant on maize, millet, and sorghum—facing the greatest risks. This disparity threatens progress toward:

• SDG 2 (Zero Hunger): Yield declines in staple crops jeopardize food availability and nutrition.
• SDG 1 (No Poverty): Reduced agricultural productivity may deepen poverty among smallholder farmers dependent on vulnerable crops.
• SDG 13 (Climate Action): Highlights the need for urgent adaptation strategies to mitigate adverse effects on agriculture.

Role of Adaptation and Other Factors in Future Crop Yields

Climate change is one of multiple factors influencing future agricultural productivity. Key considerations include:

• Yield Gaps: Significant differences exist between current yields and potential yields achievable with access to improved seeds, fertilizers, irrigation, and farming practices.
• Technological and Management Improvements: Adoption of best practices and development of climate-resilient crop varieties can offset climate-induced yield declines.
• Investment Needs: Achieving yield improvements requires substantial investments in agricultural research, infrastructure, and farmer support systems.

Case Study: Maize Yield in Kenya

In Kenya, current maize yields average 1.4 tonnes per hectare, while potential yields with optimal technologies reach 4.2 tonnes per hectare. Even under severe climate scenarios projecting a 20-25% yield decline, the reduction (~0.3 tonnes) is smaller than the existing yield gap (2.8 tonnes), indicating significant room for improvement through adaptation and technology adoption.

Non-Staple Crops: Fruits, Vegetables, and Legumes

Non-staple crops are vital for nutrition, providing essential micronutrients and proteins. Although fewer studies exist, research indicates:

• CO₂ fertilization can increase yields by approximately 22% on average, with legumes benefiting more than leafy vegetables.
• High temperature increases (e.g., 4°C) may reduce yields by about 5%, with greater declines in warmer regions and potential increases in cooler areas.
• Overall, climate change effects on non-staple crops vary widely by crop type and geography, influencing nutrition security and agricultural economies.

Conclusion and Path Forward

Climate change presents complex challenges to global agriculture, with uneven impacts threatening food security and livelihoods, especially in vulnerable regions. Addressing these challenges aligns with multiple SDGs and requires:

1. Implementing climate adaptation strategies to protect and enhance crop yields.
2. Investing in agricultural technologies and practices to close yield gaps.
3. Promoting equitable access to resources for smallholder farmers to reduce poverty and hunger.
4. Strengthening global efforts to reduce carbon emissions and mitigate climate change.

Future research and policy must integrate these approaches to ensure resilient food systems capable of sustaining a growing global population.

References

• Jägermeyr et al., Nature Food, Climate Impact Studies on Crop Yields
• Scheelbeek et al. (2017), Systematic Review on CO₂ Effects on Crop Yields
• Alae-Carew et al. (2020), Review on Fruit, Nuts, and Seeds Yields under Climate Change
• Our World In Data, Climate Change and Agriculture Series by Hannah Ritchie

1. Sustainable Development Goals (SDGs) Addressed or Connected

1. SDG 2: Zero Hunger
   • The article focuses on the impact of climate change on crop yields, food production, and food security, which directly relates to ending hunger and ensuring food availability.
2. SDG 13: Climate Action
   • The article discusses climate change effects on agriculture, emphasizing the need to reduce carbon emissions and adapt to climate impacts.
3. SDG 1: No Poverty
   • It highlights how yield declines could push farmers deeper into poverty, especially in vulnerable regions.
4. SDG 12: Responsible Consumption and Production
   • The article touches on sustainable agricultural practices and closing yield gaps through better technologies and practices.
5. SDG 15: Life on Land
   • Although less directly, the article’s focus on agriculture and climate impacts relates to sustainable land use and ecosystem management.

2. Specific Targets Under Those SDGs Identified

1. SDG 2: Zero Hunger
   • Target 2.3: By 2030, double the agricultural productivity and incomes of small-scale food producers, including through secure and equal access to land, technology, and markets.
   • Target 2.4: Ensure sustainable food production systems and implement resilient agricultural practices that increase productivity and production, help maintain ecosystems, and strengthen capacity for adaptation to climate change.
   • Target 2.1: End hunger and ensure access by all people to safe, nutritious, and sufficient food all year round.
2. SDG 13: Climate Action
   • Target 13.1: Strengthen resilience and adaptive capacity to climate-related hazards and natural disasters in all countries.
   • Target 13.2: Integrate climate change measures into national policies, strategies, and planning.
   • Target 13.3: Improve education, awareness-raising, and human and institutional capacity on climate change mitigation, adaptation, impact reduction, and early warning.
3. SDG 1: No Poverty
   • Target 1.2: Reduce at least by half the proportion of men, women, and children living in poverty in all its dimensions according to national definitions.
4. SDG 12: Responsible Consumption and Production
   • Target 12.3: Halve per capita global food waste at the retail and consumer levels and reduce food losses along production and supply chains.
   • Target 12.4: Achieve the environmentally sound management of chemicals and all wastes throughout their life cycle.
5. SDG 15: Life on Land
   • Target 15.3: Combat desertification, restore degraded land and soil, including land affected by desertification, drought, and floods, and strive to achieve a land degradation-neutral world.

3. Indicators Mentioned or Implied to Measure Progress

1. Crop Yield Changes
   • Percentage change in yields of staple crops such as maize, wheat, rice, soybeans, millet, and sorghum under different climate scenarios (e.g., RCP2.6 and RCP8.5).
   • Regional yield variations by latitude and climate zone.
2. Food Availability and Consumption
   • Per capita supply of staple crops (e.g., maize and millet) available for consumption at the end of the supply chain.
   • Prevalence of undernourishment in regions affected by yield changes.
3. Water Stress and Extreme Weather Impact
   • Yield penalties due to increased waterlogging and drought stress measured as percentage decline in yields.
   • Frequency and intensity of extreme weather events affecting agricultural productivity.
4. Yield Gaps
   • Difference between current yields and attainable yields using best available technologies and practices (e.g., maize yield gap in Kenya).
5. Carbon Emissions
   • Levels of atmospheric CO₂ concentrations and their fertilization effects on crop yields.
   • Global carbon emissions reduction trajectories (e.g., scenarios like RCP2.6).

4. Table of SDGs, Targets, and Indicators

Source: geneticliteracyproject.org