Once these external costs are internalized and thus taken into consideration in the calculations of polluters and natural resource users, markets operate more efficiently and help improve social welfare through better allocation. Environmental taxes can also raise additional revenues and boost fiscal space, contributing to the need of developing countries to invest in infrastructure and other measures to pursue the SDGs and increase resilience to climate change impacts. In OECD countries, environmental taxes have already been widely used to decouple GHG emissions from economic growth and raise revenues for green investment. Similarly, in many developing economies, environmental taxes have been implemented to reduce pollution, foster conservation and reduce GHG emissions - as exemplified by taxes on fossil fuels in Costa Rica (see Cottrell et al. In countries that already raise substantial revenue from environmental taxes, review and administrative improvement can enhance the performance of such taxes and ensure that their positive environmental impacts are maximized, as exemplified by the efforts of China to reform its system of pollution charging into a more efficient system of environmental taxation.