<P> Some people are skeptical of the environmental movement and feel that it is more deeply rooted in politics than science . Although there have been serious debates about climate change and effects of some pesticides and herbicides that mimic animal sex steroids, science has shown that some of the claims of environmentalists have credence . </P> <P> Claims made by environmentalists may be perceived as veiled attacks on industry and globalization rather than legitimate environmental concerns . Detractors note that a significant number of environmental theories and predictions have been inaccurate and suggest that the regulations recommended by environmentalists will more likely harm society rather than help nature . </P> <P> Specific examples include when Rachel Carson, in her book Silent Spring, suggested that the pesticide DDT caused cancer and drastically harmed ecosystems . DDT is highly toxic to aquatic life, including crawfish, daphnids, sea shrimp and many species of fish . However, DDT is also used to control malaria . </P> <P> Prominent novelist and Harvard Medical School graduate Michael Crichton appeared before the U.S. Senate Committee on Environment and Public Works to address such concerns and recommended the employment of double - blind experimentation in environmental research . Crichton suggested that because environmental issues are so political in nature, policy makers need neutral, conclusive data to base their decisions on, rather than conjecture and rhetoric, and double - blind experiments are the most efficient way to achieve that aim . </P>

When did the environmental movement first start in the us