Earth Day, event first observed internationally on April 22, 1970, to emphasize the necessity for the conservation of the world's natural resources. Starting as a student-led campus movement, initially observed on March 21, Earth Day has become a major educational and media event. Environmentalists use it as an occasion to sum up current environmental problems of the planet: the pollution of air, water, and soils; the destruction of habitats; the decimation of hundreds of thousands of plant and animal species; and the depletion of nonrenewable resources. The emphasis is on solutions that will slow and possibly reverse the negative effects of human activities. Such solutions include recycling of manufactured materials, fuel and energy conservation, banning the use of harmful chemicals, halting the destruction of major habitats such as rain forests, and protecting endangered species.