Climate variability and change pose significant challenges to agricultural production, ecosystem sustainability, and rural livelihoods in Ethiopia. Understanding climate trends, local perceptions, ecosystem resilience, and the climate mitigation potential of natural resources is essential for developing effective adaptation and mitigation strategies. This dissertation investigated climate variability, community perceptions, woody plant diversity, and the climate change mitigation potential of church forest ecosystems across agroecological zones in Jabitehinan District, Northwest Ethiopia. The study employed a mixed-methods research approach integrating meteorological, socioeconomic, ecological, and carbon stock data. Historical climate records from six meteorological stations obtained from the Ethiopian National Meteorological Agency were analyzed using the Mann–Kendall trend test, Sen’s slope estimator, precipitation concentration index, and spatial interpolation techniques. Household survey data were collected from 361 farmers selected through a twostage sampling procedure, complemented by key informant interviews and focus group discussions. Ecological data were gathered from four church forests distributed across semiarid, sub-humid, and temperate-highland agroecological zones using systematically established vegetation plots. Woody species composition, diversity, structure, regeneration status, and carbon stock were assessed through field measurements and standard ecological and biomass estimation methods. The climate analysis revealed declining rainfall trends across seasons, with annual rainfall decreasing at a rate of 0.0122 mm, while mean annual temperature increased by 0.206°C. Maximum, minimum, and mean temperatures increased by 0.014°C, 0.029°C, and 0.037°C per decade, respectively. Spatial analysis showed considerable variation in rainfall distribution, with the highest annual rainfall occurring in the upper highlands. Farmers widely perceived declining and increasingly erratic rainfall, delayed onset and early cessation of rainy seasons, rising temperatures, and shifting planting periods. Perceptions varied significantly among agroecological zones, with semi-arid communities reporting stronger climate-related changes. Gender, education, access to irrigation, training opportunities, climate information, indigenous knowledge, and extension services significantly influenced climate change awareness. Ecological assessment identified 49 woody species belonging to 35 families across the three church forests. Fabaceae, Euphorbiaceae, Cupressaceae, and Oleaceae were the dominant families. Shannon–Wiener xiv diversity values ranged from 2.58 to 3.29, indicating moderate to high species diversity. Forest structural analysis showed dominance of individuals in lower height classes, while diameter class distributions varied among forests. Three church forests exhibited good regeneration status, whereas one showed fair regeneration, demonstrating the important role of church forests in conserving biodiversity and maintaining ecosystem integrity. Carbon stock assessment demonstrated significant variation among agroecological zones. Church forests in the semi-arid zone stored substantially higher carbon than those in the sub-humid and temperate-highland zones. Mean aboveground, belowground, and total carbon stocks across the study area were 33.4 t ha⁻¹, 8.3 t ha⁻¹, and 41.8 t ha⁻¹, respectively. Analysis of variance indicated significant differences in carbon storage among agroecological zones (F = 3.54, p < 0.033). These findings confirm that church forests contribute not only to biodiversity conservation but also to climate change mitigation through carbon sequestration. The study demonstrates that Jabitehinan District is experiencing noticeable climate variability characterized by declining rainfall and rising temperatures, which are widely recognized by local communities. At the same time, church forests serve as important ecological refuges that conserve woody plant diversity, support forest regeneration, and provide measurable carbon sequestration benefits. Strengthening climate-smart agricultural practices, enhancing climate information services, promoting environmental education, and supporting community-based conservation of church forests are essential for improving resilience and advancing sustainable climate adaptation and mitigation efforts in Northwest Ethiopia.