Key message 1 – Climate change will make agriculture less productive.
The scale and pace of human-induced climate change is unprecedented (IPCC, 2021). Global average temperatures are rising, and extreme events such as heatwaves, cyclones, heavy rain, and droughts are becoming more frequent. These phenomena are widespread, making weather conditions both harsher and more unpredictable across the globe. With each Intergovernmental Panel on Climate Change (IPCC) assessment, the scale of observed and expected climate change increases, with worsening impacts on natural and human systems (UNEP, 2021). Even with aggressive climate policy, climate change will increase over the 21st century. A future with more unpredictable and volatile weather systems is unavoidable, creating significant repercussions for how humans interact with, rely on, and survive in the natural environment.
The agricultural sector is highly vulnerable to the impacts of climate change, particularly in low- and middle-income countries. Since agriculture is acutely dependent on weather and climate, changes in temperatures and precipitation directly affect growing conditions and yields. At a global level, a 1°C rise in temperatures could reduce crop yields by 7.4% for maize, 3.2% for rice, and 6% for wheat (Zhao et al., 2017). In tropical and subtropical regions, the impact from higher temperatures on agricultural revenue is expected to be larger than that in temperate regions (Mendelsohn, 2008). This implies that developing countries are disproportionately exposed. In Africa and Asia, a high-emissions scenario (RCP8.5) could see major crop yields fall dramatically by 2050 (Figure 1).
Figure 1: A high-emissions scenario would be catastrophic for major crop yields in African and Asian countries
Higher temperatures and greater weather variability pose a dual threat to agricultural production. Across the globe, deviations of precipitation and temperature from long-run averages have a significant impact on yields and productivity (Mearns et al., 1997, Dixon et al., 2003). These fluctuations, referred to as inter-annual climate variability, are expected to worsen with climate change and add to the already high levels of risk and uncertainty present in agricultural production in developing countries (Sonwa et al., 2017). In semi-arid regions such as the Sahel and the Horn of Africa, heavier seasonal rainfalls can cause flooding and damage to crops, while droughts can lead to famines (WMO, 2021). IGC researchers have also found greater variability in weather leads to greater variability in profitability (Rosenzweig & Udry, 2020).
Figure 2: Most of the world’s agricultural workforce are in countries that are highly vulnerable to climate change
Lower or more variable agricultural output will have significant ramifications for food security, poverty, and development. On average, agriculture accounts for two-thirds of the workforce and one-third of GDP across low-income countries (World Bank, 2021). Most of the global agricultural workforce lives in countries at high risk of climate change (Figure 2). The prevalence of subsistence farming, food insecurity, and extreme poverty across the developing world make millions acutely vulnerable to the impacts of climate change. These impacts could lead to internal climate migration of up to 143 million people by 2050, adding significant pressure to infrastructure and social support systems (World Bank, 2018). Climate shocks can trigger conflicts, such as between pastoralists and farmers (Nunn & McGuirk, 2021), which may become more frequent. Gender disparities may also widen, with some evidence suggesting that the costs of climate change fall disproportionately on women-headed households (Wossen, 2018, Eskander & Steele, 2019). Together, these patterns point to exacerbating inequality and vulnerability in already unequal and vulnerable contexts.