The chief ecosystem impacts result from large-scale hydropower projects in forests, although surface mining causes significant damage in some areas. At the regional scale, fine particles and ozone are the most widespread health-damaging pollutants from energy use, and can extend hundreds of kilometres from their sources. Similarly, nitrogen and sulphur emissions lead to acid deposition far from their sources. Such deposition is associated with damage to forests, soils, and lakes in various parts of the world. Thus energy use is the human activity most closely linked to potential climate change.
Climate change is feared to have significant direct impacts on human health and on ecosystems.
There are important opportunities for 'no regrets' strategies that achieve benefits at more than one scale. The President and Fellows of Harvard College.