Page 135 - AJWEP-22-5

Asian Journal of Water, Environment and Pollution. Vol. 22, No. 5 (2025), pp. 129-152.
doi: 10.36922/AJWEP025190142

ORIGINAL RESEARCH ARTICLE

Spatiotemporal climate trends and policy assessment
in Ethiopia’s Lake Tana Basin amid global carbon

dioxide emissions

Hellen Messel * Mehretie Belay 1† , Mintesenote Azene 2† , Gashaw Bimrew ,
1
2
Abebe Arega , and Dawite Bezabh 4
3
1 Department of Geography and Environmental Studies, Faculty of Social Sciences, Bahir Dar University, Bahir Dar, Ethiopia
2 Institute of Disaster Risk Management and Food Security Studies, Bahir Dar University, Bahir Dar, Ethiopia
3 Department of Geography and Environmental Studies, Faculty of Social Sciences, Wollo University, Wollo, Ethiopia
4 Department of Geography and Environmental Studies, Faculty of Social Sciences, Woldia University, Woldia, Ethiopia
† These authors contributed equally to this work.
*Corresponding author: Hellen Messel (helen.mesel@bdu.edu.et)

Received: May 6, 2025; Revised: June 4, 2025; Accepted: June 9, 2025; Published online: July 22, 2025

Abstract: Climate change, predominantly driven by escalating global CO emissions, is significantly altering
2
global and regional weather patterns. The Lake Tana Basin, a critical ecological and agricultural zone, exhibits
high vulnerability to this climatic variability. This study examined long-term trends in rainfall (1900 – 2023) and
temperature (1901 – 2022) using the CenTrends and CRU datasets, along with the spatial variability of rainfall and
temperature (1981 – 2022) based on the National Aeronautics and Space Administration data. It also investigated
the relationship between climate variables and global CO emissions (using the EDGAR dataset; 1970 – 2022)
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and assessed the efficacy of local climate policies. The findings revealed pronounced spatiotemporal variability.
A significant decrease in crucial summer (Kiremt) rainfall was observed (Sen’s slope: −0.335 mm/year; p=0.011),
whereas November rainfall displayed a significant increasing trend (Sen’s slope: 0.045 mm/month; p=0.04),
contributing to rising autumn rainfall. Temperatures are rising unequivocally (p<0.05). Notable spatial variability
was also observed across different agroecological zones – for instance, the Gondar station reported an annual
rainfall with a coefficient of variation of 32.6% compared to 22.3% at Injibara. A significant decline in rainfall
was observed in Woreta and Delgi, with Mann–Kendall trend values of −0.247 (p=0.022) and −0.265 (p=0.014),
respectively. A robust, statistically significant positive correlation (r = 0.743; p<0.01) was established between
global CO emissions and local temperature changes over 53 years. An in-depth policy review identified substantial
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challenges that impede effective climate action. These results underscore the urgent need for strengthening policy
implementation and promoting targeted, location- and season-specific adaptation and mitigation strategies. These
include adopting climate-smart agricultural practices, improving carbon sequestration capacity, and aligning
local climate actions with global mitigation efforts. Participation in global climate agreements and initiatives,
integrated with local actions that contribute to global emission reduction targets, is essential for ensuring long-term
sustainability and enhancing community resilience.

Keywords: Climate change; Inverse distance-weighted; Mann–Kendall test; CenTrends; Climate research unit,
Greenhouse gas emissions; Policy analysis; Ethiopia

Volume 22 Issue 5 (2025) 129 doi: 10.36922/AJWEP025190142