Abstract
Climate change could potentially interrupt progress toward a world without hunger. A robust and coherent global pattern is discernible of the impacts of climate change on crop productivity that could have consequences for food availability. The stability of whole food systems may be at risk under climate change because of short-term variability in supply. However, the potential impact is less clear at regional scales, but it is likely that climate variability and change will exacerbate food insecurity in areas currently vulnerable to hunger and undernutrition. Likewise, it can be anticipated that food access and utilization will be affected indirectly via collateral effects on household and individual incomes, and food utilization could be impaired by loss of access to drinking water and damage to health. The evidence supports the need for considerable investment in adaptation and mitigation actions toward a “climate-smart food system” that is more resilient to climate change influences on food security.
Generated Summary
This review article examines the impacts of climate change on global food security. It synthesizes evidence on how climate change affects crop productivity, food access, utilization, and the stability of food systems. The study employs a bibliographic analysis of peer-reviewed journal papers, focusing on the distribution of evidence across different dimensions of food security since 1990. The authors also address the complexities of global food security, highlighting the interconnected risks and uncertainties. The research approach involves reviewing existing literature and synthesizing findings to identify the current understanding of climate change’s effects on food security, particularly in vulnerable regions. The scope of the review includes direct and indirect effects of climate change on crop production, livestock health, and trade, with a focus on the implications for food availability, access, utilization, and system stability. The research aims to provide a comprehensive overview of the current state of knowledge, identify gaps, and offer guidance for policy and decision-making in addressing climate change impacts on food security.
Key Findings & Statistics
- The global mean temperature has risen by 0.8°C since the 1850s.
- Demand for agricultural products is estimated to increase by about 50% by 2030.
- The proportion of the world’s undernourished population decreased from an estimated 980 million in 1990-92 to about 850 million in 2010-12.
- About 2 billion of the global population are food insecure.
- Average crop yields may decline across Africa and South Asia by 8% by the 2050s.
- Crop yields are predicted to change by -17% (wheat), -5% (maize), -15% (sorghum), and -10% (millet) in Africa, and by -16% (maize) and -11% (sorghum) in South Asia, under climate change.
- The distribution of the evidence is heavily skewed toward food availability within 70% of the publications. Access, utilization, and stability dimensions of food security are represented by only 11.9%, 13.9%, and 4.2% of the total publications on food security and climate change, respectively.
- Carbon dioxide (CO2) levels in the atmosphere have increased from about 284 ppm in 1832 to 397 ppm in 2013.
- By the end of this century, the global mean temperature could be 1.8° to 4.0°C warmer than at the end of the previous century.
- The GISS model showed that yields may decline across Africa and South America (22).
Other Important Findings
- Climate change is expected to bring warmer temperatures, changes to rainfall patterns, and increased frequency and severity of extreme weather.
- The study found a robust and coherent pattern on a global scale of the impacts of climate change on crop productivity.
- Climate change will exacerbate food insecurity in areas that already currently have a high prevalence of hunger and undernutrition.
- The distribution of the evidence across the four dimensions of food security is heavily skewed toward food availability.
- The impacts of climate change on crop productivity and production has remained consistent across global studies spanning almost 20 years of research.
- Climate change can result from natural causes and human activities.
- There is a theoretical link between the levels of greenhouse gases in the atmosphere and global warming.
- Food utilization depends upon water and sanitation and will be affected by any impact of climate change on the health environment.
Limitations Noted in the Document
- The study acknowledges limitations in current analyses of climate change impacts on food security, including the use of averages for the period 2010–2012, which do not capture specific year or short-term shocks.
- Current data only estimate calorie shortage and do not cover other dietary deficiencies and related health effects.
- Current data is derived from aggregate data, not actual household or individual-level food deficiencies, which hinders analyses of distributional effects.
- The current FAO methodology was recently improved, but the above shortcomings could not be addressed within the framework of the current method.
- The FAO methodology’s data-gathering methods were incomplete, and thus, current analyses of climate change impacts on food security are incomplete.
- The limitations arise from the use of only just over one hundred points to represent global crop production, the absence of any change in the areas suitable for crop production in future climates, limitations on how each of the model points is representative of their surrounding regions, and assumptions about varieties in the crop model parameters themselves.
- Climate change could transform the ability to produce certain products at regional and international levels.
Conclusion
The article concludes that climate change poses significant challenges to global food security, particularly in regions already vulnerable to hunger and undernutrition. The evidence indicates a robust and coherent pattern of climate change impacts on crop productivity, leading to potential consequences for food availability. The authors emphasize the need for comprehensive approaches, including macro-modeling and micro-level studies, to understand the complex interactions between climate change and food security. They highlight the importance of addressing the indirect impacts of climate change, such as those affecting food access and utilization. Furthermore, the study underscores the urgency of adaptation and mitigation actions towards a “climate-smart food system” to enhance resilience. The study provides six key messages for decision-makers: Climate change impacts will be worst in countries already suffering high levels of hunger; the consequences for global undernutrition and malnutrition of inaction are potentially large; food inequalities will increase; vulnerable populations will face greater risks; adaptation actions are needed immediately due to past emissions; and extreme weather events will likely increase risks. These precepts highlight the need for substantial investment in adaptation and mitigation actions to protect global food security, emphasizing the interconnectedness of climate change and food systems. The authors call for a “climate-smart food system” that addresses climate change impacts across all dimensions of food security, involving changes in technology, management, and policies. These efforts must consider the human dimensions of climate change impacts on food security, recognizing that food systems are driven by people and their responses to climate changes.