Abstract
After 2010, refugees through the World peaked at the highest level since WW II. Most of this increment was realized between 2011 and 2015 years in the effect of the Syrian conflict and the Arabic spring, and refugee problem that is an important problem for the world emerged. This problem was analyzed in the macroeconomic dimension, in the health dimension by different studies. However, the energy and environmental economy dimensions of this problem has not been adequately analyzed.This paper explored the cointegration and Granger causality between the refugee population, traditional energy consumption(firewood, charcoal, and coal), economic growth, environmental pollution, and deforestation by the tests of Fourier Bootstrapping ARDL (FBARDL) and Granger causality with the Fourier method in the period 1985-2020 in Ethiopia, Sudan, and Uganda. Firstly, whether the series is stationary was investigated by using Fourier unit root tests. Then, the FBARDL test determined the evidence of cointegration among the variables. Finally, by applying Granger causality with the Fourier method, the evidence of unidirectional causality running from the refugee population and traditional energy consumption to deforestation and evidence of unidirectional causality running from the refugee population and traditional energy consumption to environmental pollution were determined. The analysis results draw attention to the impacts of the increasing refugee population on deforestation, and environmental pollution. Governments must develop their long-term environmental policies in the context of the effects of refguee population on sustainability.