Observed temperature trends and projected changes under CMIP6 climate scenarios in North Shewa Zone of Amhara Region Ethiopia

Climate change is often discussed in terms of rising global averages, but the reality on the ground is far more complex, especially in places where the land rises and falls in dramatic waves. In regions like the highlands of Ethiopia, the weather is not just a single number; it is a shifting landscape of temperatures that change with every step up a mountain or down into a valley. For the farmers who live there, these shifts are not abstract concepts but daily realities that determine whether crops survive the night or wither in the heat. To understand how the climate is changing in these intricate environments, scientists look at long records of past weather and use powerful computer models to imagine what the future might hold. These models, which simulate the Earth's atmosphere under different scenarios of human activity, allow researchers to peer decades ahead, offering a glimpse of the thermal conditions that will shape the lives of millions.

In the North Shewa Zone of Ethiopia, a region characterized by steep slopes and diverse farming communities, a team of researchers set out to map exactly how temperatures have changed over the last three decades and how they might change in the coming century. They focused on two specific measures of heat: the hottest part of the day and the coldest part of the night. By analyzing daily temperature records from 1992 to 2022, the team confirmed that the area is indeed getting warmer. The data showed a clear, steady rise in both the daily highs and the daily lows. The nights are warming slightly slower than the days, but both are climbing at a rate that adds up to a noticeable shift over time. In total, the average hottest days have warmed by nearly three-quarters of a degree, while the average coldest nights have warmed by about two-thirds of a degree. This warming is not uniform; it varies significantly depending on the altitude, with the lowlands and highlands experiencing different degrees of change, yet the overall trend is unmistakably upward.

Looking ahead, the researchers used a collection of five advanced climate models to project what the North Shewa Zone might look like in the middle of this century and at the end of it. They ran these simulations under two different paths for human society: one where greenhouse gas emissions are reduced to a moderate level, and another where emissions continue to rise sharply. The results indicate that the warming will continue, but the severity depends entirely on which path humanity takes. By the middle of the century, temperatures are expected to rise by about one to two degrees across the board, a change that would be felt in every valley and on every hill. However, by the end of the century, the difference between the two paths becomes stark. If emissions remain high, the region could see maximum daytime temperatures soar to nearly thirty-nine degrees and minimum nighttime temperatures climb to over twenty-five degrees in the warmest areas. Even in the coldest highland pockets, the nights would rarely drop below eleven degrees, a dramatic shift from the chilly conditions that currently define those elevations.

The implications of these thermal shifts for the local agriculture are profound. Crops and livestock have evolved to thrive within specific temperature ranges, and as those ranges move, the balance of the ecosystem is disrupted. Warmer nights mean that plants cannot cool down and recover from the heat of the day, which increases their stress and reduces their ability to produce grain. Livestock, too, face greater challenges as the lack of cooling relief during the night adds to their physiological strain, potentially lowering milk yields and increasing the risk of heat-related illness. While the overall trend is toward a hotter climate, the researchers noted a crucial nuance: the warming does not guarantee that frost will disappear entirely. In the highest, most exposed parts of the zone, local conditions can still create pockets of cold air, meaning that frost remains a threat even as the average temperature rises. This creates a dual challenge for farmers who must prepare for both more frequent heat stress and the lingering risk of sudden cold snaps.

The study concludes that the North Shewa Zone is entering a new climatic era defined by higher temperatures and greater variability. The evidence suggests that without significant changes in how greenhouse gases are managed, the region will face a future where the heat is more intense and the nights are less cool. This reality demands that local communities and planners adapt their strategies, perhaps by choosing crop varieties that can withstand higher temperatures or by adjusting planting schedules to avoid the most dangerous heat periods. The research provides a clear, data-driven map of the challenges ahead, showing that while the climate is changing, the specific nature of that change is tied directly to the choices society makes today. By understanding the precise ways in which the temperature is shifting across the zone's complex terrain, farmers and leaders can better prepare to protect their livelihoods and ensure food security in a warming world.