The single important reason is deforestation. Environmental hazards are generated by industries everywhere. 2,100 million tonnes of solid waste and 340 million tonnes of hazardous waste are coming out of these industries. There has been a worldwide concern about the disposal of radioactive wastes from nuclear reactors. The stock of nuclear power stations is also ageing.
Modern warfare using chemicals and gases is also a great threat to the environment.
In early 1991, the Gulf War lasted only for 42 days. The pressing problems are the crisis of terrestrial environment and long-term impact of fires on human health. The landscape is saturated with viscous droplets of crude oil and ash. A great deal of vegetation had died or been damaged as a result of black rains and shoot deposit. In the worst affected areas, the soil is soaked with petroleum, sometimes to a depth of one meter, while pools of oil have continued to gather around damaged wells.