Exploring the impacts of greenhouse gas emissions and environmental degradation on cereal yields in East Africa

Environmental degradation and pollution have become global concerns due to climate change. Most previous studies have focused on the determinants of environmental degradation and pollution, but there are scanty studies on the environmental degradation–pollution–agriculture production nexus in cross-country studies. In this regard, this undertaking assesses the impact of environmental degradation, greenhouse gases (GHGs), agriculture methane emissions, carbon dioxide (CO2) emissions, and population growth on cereal yields in East African countries using panel data spanning 1992–2018. Pedroni and Kao cointegration methods, panel heterogeneous methods, and Granger causality are utilized to achieve the objective of the study. The Kao and Pedroni cointegration tests revealed that all the variables are cointegrated in the long run. Moreover, the Hausman test determines that Pooled mean group (PMG) provides more robust and constant results than the Mean group. The long-run results of the PMG indicated that environmental degradation enhances cereal yields in the long run. On the contrary, CO2 emissions and population growth significantly impede cereal yields in East Africa in the long run, whereas GHGs and agriculture methane emissions are statistically insignificant. In contrast, the result of Granger causality established a unidirectional causality from CO2 emissions, agriculture methane, GHGs, population growth, and environmental degradation to cereal yield. Notably, all the independent variables cause cereal yield in East Africa but not the other way. Nevertheless, East African countries require stronger policies to curtail CO2 emissions and environmental degradation and to reduce the adverse climate shocks on the agriculture sector.