1920世纪末,美国许多知识分子和政治家开始意识到了对自然资源不顾后果的消耗、人口增长和工业技术史无前例的发展对自然环境构成的威胁。一些有识之士呼吁采取措施保护自然资源。他们对环境问题的关注影响到西奥多·罗斯福总统,他很快启动了一些由政府监督实施的项目,如发展森 At the end of the 1920s, many intellectuals and politicians in the United States began to realize the threat to the natural environment caused by reckless consumption of natural resources, population growth and the unprecedented development of industrial technology. Some people of insight called for measures to protect natural resources. Their concern for environmental issues affected President Theodore Roosevelt, who promptly started a number of government oversight projects, such as the development of Mori