On the issue of health, the UNEP report says that much of the air pollution that kills an estimated 500,000 people each year comes from burning fossil fuels in power stations, industrial furnaces, and motor vehicles. Air pollution also causes an estimated four to five million new cases of chronic bronchitis, as well as millions of cases of other serious illnesses. These facts alone are reason enough to find new sources of energy and change the way it is used. However, the world's increasing appetite for fossil fuels has created an even more compelling reason to accelerate the switch to clean forms of energy, namely global climate change. However, there are solutions.
Renewable energy is abundant, clean, and inexhaustible.
It is also the most cost-effective energy source for a variety of applications, meeting between 15 and 20 percent of total world energy demand and 24 percent of the world's total electricity supply. Renewable energy in the form of traditional biomass fuels, such as wood and crop residues, represents about 14 percent of the world's total energy consumption - a larger share than coal. However, the contribution of newer renewable energy technologies is increasing rapidly, in spite of new competition from deregulated energy markets. From a small base in the 1970s, biomass, geothermal, solar, small-scale hydropower, and wind technologies have grown proportionally faster than any other electricity supply technology. The evolution of the wind energy industry has far exceeded even the most optimistic predictions in 1990.