In Kenya’s arid and semi-arid lands (ASALs), climate change and variabilityare increasingly affecting agricultural systems, raising the risk of food insecurity.Beyond climatic factors, market price fluctuations, national policies, and socialnetworks shape community responses to shocks and influence vulnerability andresilience. This study integrates climate, land-use, market, and local perceptiondata to identify locally grounded pathways through which food insecurity emergesin Kalama sub-county, Machakos County, Kenya, thereby informing targeted adaptationand policy interventions. The study used a mixed-methods approach. Secondary data on climatevariability, agricultural expansion, food production, and market prices wereprocured and analyzed. Primary qualitative data were collected through focusgroup discussions and key informant interviews with residents of Kalama subcounty.Climate trend analyses were performed to quantify rainfall and temperaturechanges since 1981. Agricultural expansion in the study area increased fourfold between 1990and 2023, reflecting adaptation through cultivation of previously unproductivelands. Innovations such as drip irrigation, sand dams, and drought-resistant cropswere reported. However, climate variability remains a major constraint: long rainsdeclined significantly (−1.32 mm/season/year; p = 0.042) while annual maximumtemperature increased by approximately 1.0°C since 1981 (+0.23°C/decade; p <0.001), undermining crop yields and food productivity. Additionally, food pricevolatility linked to global events (COVID-19, the Ukraine–Russia war) and nationalpolicies marginalizing ASALs exacerbated food insecurity. Qualitative narrativesindicated persistent food insecurity among vulnerable groups despite adaptationefforts. Findings demonstrate that climate change impacts are compoundedby global economic shocks and policy marginalization, reducing local resilienceand food system stability. Integrated policy responses are needed, includingmarket stabilization, targeted agricultural investments in ASALs, and social protectionprograms to buffer vulnerable communities against climate and economicshocks.