Combining scientific and local knowledge to understand climate change effects in high mountains: A case study from Porshinev Jamoat, Tajikistan

Abstract

While climate change is widely recognised to threaten livelihoods and sustainable development, communities at high altitudes are some of the most vulnerable because of their low adaptive capacity and fragile environment. The Pamir has already experienced climate uncertainties given that this is the poorest, most marginalised and least developed region of Tajikistan. Changes in weather patterns and hydrological cycles create challenges for local farmers who depend on a high level of subsidised agriculture. Due to sparse instrumental data, as well as the low accuracy of climate models in this mountainous area, current local climate trends are poorly understood. To address these challenges, a combination of local knowledge with scientific data is a viable option. Here we analysed 84 years of air temperature and precipitation data and conducted semi-structured interviews with local farmers. Average annual air temperature increased significantly during this period, with winter and spring temperatures significantly increasing; insignificant increasing trends were observed during summer and autumn. During winter and spring, only May did not experience significant temperature increases. Precipitation exhibited a gradual (but insignificant) decline of about 46 mm during the 84-year period in a region where annual precipitation is about 250–300 mm. Precipitation decreased in winter and spring and increased in summer and autumn. This shift affects the ratio between solid and liquid precipitation and reflects a decrease in snow-pack accumulation in the mountains, which decreases water availability. The shift of the rainy season to summertime decreased the local thermal regime and affected crop maturation. Local farmers' perceptions correlated well with the mean and seasonal precipitation changes and mean and winter air temperature changes. Discrepancies between perceptions and actual data occurred related to summer temperature change; 46% of respondents perceived a change in annual temperature, 56% perceived an increase in winter and 71% a decrease in summer temperature. For precipitation, 77% reported a change in annual precipitation, 80% a decrease in winter precipitation and 54% an increase in summer precipitation. Changes in annual air temperature and precipitation affect the growing season and plant maturation time and therefore bring uncertainties to local cropping systems.