Research assistance
2.0 Rising Temperatures and Agricultural Productivity
The ability of agriculture to support increasing populations has been a persistent global issue and remains central to policy debates. Although food production has advanced significantly over the past fifty years, food insecurity persists in many areas. The FAO (2005b) estimated that around 850 million people in developing countries faced hunger between 2000 and 2002, with half located in Asia. Addressing poverty and hunger was a key objective of the United Nations’ Millennium Development Goals (MDGs), established in 2000, which aimed to halve global hunger rates between 1990 and 2015 (World Bank, 2003). However, achieving food security remains a major challenge, with projections suggesting a substantial increase in cereal production will be necessary by 2025.
Rising temperatures degrade soil health by accelerating organic matter decomposition, leading to nutrient depletion. Lal (2004) noted that heightened microbial activity in warmer soils speeds up nutrient cycling, which, without proper management, can reduce soil fertility. Additionally, higher temperatures contribute to increased soil salinity and decreased moisture retention, negatively impacting crop yields (FAO, 2021).
Elevated temperatures also intensify evapotranspiration, worsening water scarcity in farming regions. Research by Wang et al. (2017) shows that irrigation demands rise with temperature increases, straining already limited water supplies. Drought-prone areas are especially at risk, with declining groundwater levels threatening long-term agricultural viability (IPCC, 2021). These effects extend beyond reduced crop output, impacting economies and societies. Small-scale farmers in developing nations are particularly vulnerable due to limited access to adaptive technologies and financial resources (Morton, 2007). Additionally, lower yields drive up food prices, exacerbating food insecurity for marginalized populations (Nelson et al., 2014).
Growth in crop yields has slowed in many regions due to reduced investments in agricultural research, irrigation, and rural infrastructure, alongside worsening water scarcity (FAO, 2001). Climate change further compounds these challenges. While some studies (e.g., Parry et al., 1999) suggest that moderate warming (up to 1°C above historical averages) may not drastically affect food supply—assuming farmers adapt and benefit from higher CO₂ levels—the broader implications remain concerning.
2.2 Rainfall Variability and Agricultural Productivity
Climate change, a natural yet increasingly urgent global issue, significantly affects agriculture, water resources, markets, and ecosystems. As a climate-sensitive sector, agricultural productivity depends on weather patterns, management practices, market conditions, and technological advancements. Among these, climate is the most critical determinant of output. Erratic rainfall—characterized by delayed onset, irregular distribution, and premature cessation—disrupts crop development. Trenberth (2011) found that rainfall variability impairs germination, growth stages, and final yields. Inadequate rainfall during key phases, such as flowering and grain filling, can drastically reduce productivity (Rosenzweig et al., 2014).
While sufficient rainfall maintains soil moisture for plant growth, excessive precipitation can cause soil erosion and nutrient leaching, degrading fertility (Lal, 2004). Conversely, prolonged droughts deplete soil moisture, hindering crop survival (FAO, 2021).
Rainfall patterns also dictate water availability for irrigation. Unpredictable or reduced rainfall diminishes river flows and groundwater recharge, leading to shortages in irrigation-dependent farming (Shah et al., 2019). Rainfed agricultural systems are especially susceptible to yield losses from irregular precipitation (IPCC, 2021).
Recognizing climate change’s impact on livelihoods, ecosystems, and resources underscores the need for effective adaptation and mitigation strategies. Between 1970 and 2004, global greenhouse gas (GHG) emissions surged by 70%, intensifying climate-related risks. Sustainable strategies are essential to minimize adverse effects on natural resources, crop yields, and food security.
2.3 Extreme Weather Events and Agricultural Productivity
Droughts rank among the most devastating extreme weather events for agriculture, reducing soil moisture, impeding germination, and limiting irrigation water. Prolonged droughts severely diminish yields, particularly in rainfed systems. For instance, maize and wheat production in sub-Saharan Africa and South Asia have suffered due to recurrent droughts.
Deforestation and land-use changes also play a critical role in climate-agriculture interactions. Agricultural expansion often drives large-scale deforestation. Between 1960 and 2019, one-third of the global land area underwent changes—four times previous estimates. These shifts include afforestation and farmland abandonment in the northern hemisphere, contrasted with deforestation and agricultural expansion in the south. Such changes not only reduce forests’ carbon-absorbing capacity but also elevate atmospheric CO₂ levels (Negi & Azeez, 2022).
Floods cause soil erosion, nutrient loss, and waterlogging, damaging crops. In 2011, drought and flooding accounted for over 70% of U.S. crop yield losses (Bailey-Serres et al., 2012). Increasing precipitation trends have amplified soil and nutrient runoff, along with waterlogging, a major cause of production declines in the U.S. Midwest (Luce, 2015; Wiebold, 2015). Excess water suffocates roots and fosters plant diseases. In Southeast Asia, floods have devastated rice and soybean crops, triggering food shortages and economic strain (Yuan et al., 2024).
Heatwaves escalate evapotranspiration, drying soils and stressing crops. High temperatures during critical phases like flowering impair grain formation. Research indicates that U.S. corn yields drop sharply above 30°C, with each additional degree causing exponential losses (Carrera, Savin, & Slafer, 2024).
