Environmental Impacts of Fossil Fuels Serious adverse environmental impacts arise from the emission of carbon dioxide and the oxides of sulphur and nitrogen when fossil fuels are burned. The contribution to the "greenhouse effect", stemming from the emission of carbon dioxide which inevitably occurs when fossil fuels burn, may lead to global increases in temperature and sea-level, with resulting shifts in food-producing areas and patterns of disease, and species extinction. These changes, and the migration of people they could cause, could affect peace and international security. Acidic pollution, arising from the emission of the oxides of sulphur and nitrogen, is implicated in the increasing incidence of asthma and other respiratory diseases, the acidification of lakes, and damage to trees and buildings. Increasing public pressure to limit or reduce these emissions will severely constrain the reliance that could be placed on fossil fuels as a source of increased energy supply. Unless this lost fossil fuel output is replaced on a large scale by accepted alternatives, the cost, in terms of economic development foregone, will be very high.