Rainfall Projections from Coupled Model Intercomparison Project Phase 6 in the Volta River Basin: Implications on Achieving Sustainable Development

Climate change has become a global issue, not only because it affects the intensity and frequency of rainfall but also because it impacts the economic development of regions whose economies heavily rely on rainfall, such as the West African region. Hence, the need for this study, which is aimed at understanding how rainfall may change in the future over the Sahel, Savannah, and coastal zones of the Volta River Basin (VRB). The trends and changes in rainfall between 2021–2050 and 1985–2014 under the Shared Socioeconomic Pathway (SSP2-4.5 and SSP5-8.5) scenarios were analyzed after evaluating the performance of three climate models from the Coupled Model Intercomparison Project Phase 6 (CMIP6) using Climate Hazards Group InfraRed Precipitation with Station data (CHIRPS) as observation. The results show, in general, a relatively high correlation and low spatial biases for rainfall (r > 0.91, −20% < Pbias < 20%) over the entire Volta Basin for the models’ ensemble mean. An increasing trend and projected increase in annual rainfall under the SSP2-4.5 scenario is 6.0% (Sahel), 7.3% (Savannah), and 2.6% (VRB), but a decrease of 1.1% in the coastal zone. Similarly, under SSP5-8.5, the annual rainfall is projected to increase by 32.5% (Sahel), +22.8% (Savannah), 23.0% (coastal), and 24.9% (VRB), with the increase being more pronounced under SSP5-8.5 compared to the SSP2-4.5 scenario. The findings of the study would be useful for planning and designing climate change adaptation measures to achieve sustainable development at the VRB

An increase in temperature under the shared socioeconomic scenarios in the Volta River Basin, West Africa: implications for economic development

This study examined the temperature variations in West Africa's Volta River Basin (VRB) from 2021 to 2050 in comparison to the historical period (1985–2014) under two Shared Socioeconomic Pathway Scenarios (SSP2-4.5 and SSP5-8.5). Datasets from three Global Climate Models (GCMs) of the sixth Coupled Model Intercomparison Project (CMIP6) were used. The GCMs and their ensemble were evaluated on a monthly scale. The study used the ensemble mean to analyse the changes in annual and monthly temperature over the Sahel, Savannah, Guinea Coast, and the entire Volta basin. The results demonstrate the individual GCMs reproduced the observed temperature pattern at the VRB, though with some overestimations, but the ensemble mean indicated a better representation of the observed temperature. A warming trend in the basin is projected under both climate scenarios, with higher temperatures projected under SSP5-8.5 compared to SSP2-4.5 in all three zones. The mean annual temperature is projected to increase by 0.8 and 1.0 °C, with a statistically increasing trend under SSP2-4.5 and SSP5-8.5, respectively. Without a doubt, high temperatures, if unchecked, can erupt into resource conflict among the competing interest groups, thereby affecting the achievement of economic development at the VRB. HIGHLIGHTS The study contributes to understanding climate change impacts on economic development.; Temperature in VRB to rise up to 1 °C by 2050.; Temperature rise will lead to water shortages, extinction of fish species, and livelihood loss.; Temperature rise could lead to droughts, pest invasion, reduced crop yields, food security, and economic growth.; VRB is home to large hydropower dams, which could be affected by temperature rise.

Road improvement enhances smallholder productivity and reduces forest encroachment in Ghana

Agriculture employs about 70% of the active labour force, yet contributes only 30% to the Gross Domestic Product (GDP) of Sub-Saharan Africa. About 60% of African farmers cultivate mainly for household consumption on 2–2.5 ha of land and depend upon roads to access local and regional markets. Forest encroachment by smallholder farmers is a major cause of deforestation in Africa. We used regression analysis to determine the degree to which road improvement influenced farm size, forest encroachment and market participation in rural Ghana. We obtained data on household size and characteristics and farm plot size from 300 farmers in 10 communities. Farms accessible by improved roads had stable or slightly declining areas under cultivation. Improved roads led to better market integration, more use of farm inputs and higher yields. Farmers in areas with unpaved roads used fewer inputs, had less market penetration and were forced to encroach on forests for additional farmland to increase production. Our evidence suggests that linking rural people more efficiently to markets by improving roads will encourage commercial farming and reduce farm expansion into forests. Improved agriculture alone will not limit forest encroachment. Enforcement of forest protection regulations will also be needed to restrict encroachment