The fact that environmental degradation and the problems it causes have reached levels that threaten life on the planet has increased the importance of policies that are agreed upon at the global level and will be adopted and implemented by all countries. Policies determined in this framework are intended to be implemented by national governments with various tools, especially development plans and budget strategies. Directing public expenditures in line with sustainable development goals is among the basic strategies that can be applied in this area. The findings of this study, which examines the effects of environmental degradation in terms of public expenditures in BIMSTEC countries located in a sensitive region, show that public expenditures put pressure on environmental quality and cause environmental degradation by increasing carbon emissions. Therefore, it is important to implement public policies in line with global and regional strategies that will ensure environmental protection and sustainable development, and to realize public expenditures in a way that prioritizes environmental efficiency within the framework of a holistic financial plan covering all sectors.