Climate change and food insecurity: perspectives from Kalama in Machakos County, Kenya

Introduction In Kenya’s arid and semi-arid lands (ASALs), climate change and variability are increasingly affecting agricultural systems, raising the risk of food insecurity. Beyond climatic factors, market price fluctuations, national policies, and social networks shape community responses to shocks and influence vulnerability and resilience. This study integrates climate, land-use, market, and local perception data to identify locally grounded pathways through which food insecurity emerges in Kalama sub-county, Machakos County, Kenya, thereby informing targeted adaptation and policy interventions. Methods The study used a mixed-methods approach. Secondary data on climate variability, agricultural expansion, food production, and market prices were procured and analyzed. Primary qualitative data were collected through focus group discussions and key informant interviews with residents of Kalama sub-county. Climate trend analyses were performed to quantify rainfall and temperature changes since 1981. Results Agricultural expansion in the study area increased fourfold between 1990 and 2023, reflecting adaptation through cultivation of previously unproductive lands. Innovations such as drip irrigation, sand dams, and drought-resistant crops were reported. However, climate variability remains a major constraint: long rains declined significantly (−1.32 mm/season/year; p = 0.042) while annual maximum temperature increased by approximately 1.0°C since 1981 (+0.23°C/decade; p 0.001), undermining crop yields and food productivity. Additionally, food price volatility linked to global events (COVID-19, the Ukraine–Russia war) and national policies marginalizing ASALs exacerbated food insecurity. Qualitative narratives indicated persistent food insecurity among vulnerable groups despite adaptation efforts. Discussion Findings demonstrate that climate change impacts are compounded by global economic shocks and policy marginalization, reducing local resilience and food system stability. Integrated policy responses are needed, including market stabilization, targeted agricultural investments in ASALs, and social protection programs to buffer vulnerable communities against climate and economic shocks.