## 3 Results and Discussion
### Are Agroecosystems Under Threat? Since the inception of agriculture, ensuring food security has been essential to human survival, yet this stability is heavily reliant on the resilience of agroecosystems. These complex systems, comprising diverse plant, animal, and microbial interactions, face intensifying pressures from climate externalities, land degradation, and biodiversity loss. To understand the scale of these risks, several researchers [17; 100] have performed simulations and modelling techniques to project future climate extremes. In this section, we will take a general view of the future of agroecosystems globally, examining whether they can support food security in the years to come. Climate externalities are anticipated to persist well into the foreseeable future [12]. These projections have been substantiated in Ethiopia, where [PERSON] et al. [98] observed significant upward temperature trends for 2041-2060 and 2081-2100, particularly under RCP6.0 and RCP8.5 scenarios. Similar findings were reported by [PERSON] et al. [101] for Kastina State, Nigeria, where projections indicate rising temperatures coupled with decreasing precipitation levels by 2050. [PERSON] et al. [13] further suggest that extreme climate indices' frequency and intensity will increase, particularly under the SSP5-8.5 high-emission scenario. They indicate that while extreme high precipitation and temperature events may increase moderately during the early sub-period of the 21 st century (2026-2045), with minimal variation across emission scenarios, the differences in severity are expected to intensify by the mid-21 st century (2041-2060). Furthermore, the projections by [PERSON] et al. [102] indicate substantial shifts in temperature extremes across multiple warming levels within nine climate zones in India, forecasting increases in hot temperature extremes alongside decreases in cold extremes. For instance, under a 3 \({}^{\circ}\)C warming scenario (RCP8.5) and a 2 \({}^{\circ}\)C warming scenario (RCP4.5),the Warm Spell Duration Index is projected to rise by 131 and 66 days, respectively. Additionally, hot days and warm nights are expected to increase significantly, while cold days and nights are projected to decrease. These trends are expected to persist through at least 2070. Supporting these findings, [PERSON] and [PERSON] (2013) observed a significant upward trend in temperatures and declining rainfall in southeastern sub-basins. Meteorological forecasts for 2017-2027 predict a reduction in rainfall (significant at the 0.05 level) and an increase in maximum temperature (significant at the 0.01 level), predisposing these regions to arid conditions and increasing the likelihood of severe droughs. Consequently, these anticipated shifts in temperature and precipitation pose severe threats to agroecosystems, as higher temperatures increase the likelihood of prolonged droughs and extreme heat events; they intensify risks to crop yields, reduce agricultural productivity, intensify water scarcity, and drive migration pressures in affected areas. In regions where agricultural production is rain-fed, such as Ethiopia and Nigeria, these changes jeopardise crop productivity and food security. Declining precipitation will likely diminish agricultural yield potential, while increasing temperatures advance drier conditions in the Mediterranean regions. For instance, [PERSON] et al. (2017) project that winter wheat in the Swiss Central Plateau will experience increased heat stress days (Tmax \(\geq\) 30 \({}^{\circ}\)C) during critical flowering and early grain-filling stages. Under RCP2.6 (mitigated climate change), heat stress days are projected to increase from an average of 1.5 days (1982-2006) to 2.1 days by 2075-2099 and to 3.6 days under RCP8.5 (unmitigated emissions). Using the [PERSON] cereal phenology model, [PERSON] et al. (2017) emphasised that early-maturing wheat varieties might experience less heat stress than late-maturing ones, although both face elevated stress levels under high-emission scenarios by the end of the century.