Under Gorbachev's leadership, the official attitude toward the environment changed. Various social and economic factors helped produce this change. To maintain economic growth through the 1980s, a period in which the labor force had been declining significantly, intensive and more prudent use of both natural and human resources was required. At the same time, glasnost' provided an outlet for widespread discussion of environmental issues, and a genuine grass-roots ecological movement arose to champion causes similar to the ecological concerns of the West. Public campaigns were mounted to protect Lake Baykal from industrial pollution and to halt the precipitous decline in the water levels of the Caspian Sea, the Sea of Azov, and, most urgently, the Aral Sea. A grandiose scheme to divert the northern rivers southward had been counted on to replenish these seas, but for both economic and environmental reasons, the project was canceled in 1986.