The years between 1900 and 1945 were very difficult for humanity. In this period, not only were there two world wars to survive but also some of the worst parts of the social, economic, and environmental challenges of sustainable development all began to make themselves felt. The one area in which progress was made was in the social context, in which the rights of workers and the welfare state expanded. The idea of ‘development’, especially for the developing world, also evolved in this period. In the economic arena, the world went up, and then crashed in the Great Depression, producing negative results that were unprecedented. In environmental terms, positive templates were created for some habitat management, some wildlife law, and parts of freshwater conservation. Where there was not so much success was with regard to air and chemical pollution.
