Pollution of drinking water remains Americans’ top environmental concern, and few ever say that the government is doing “too much” to protect the environment. 62% of Americans say that they worry at least “a fair amount” about climate change, including 42% who worry “a great deal” about it. 61% of Americans recognize that pollution from human activities is the primary cause of increases in the Earth’s temperature over the past century. 59% of Americans recognize that the effects of global warming have already begun. Only 19% of Americans say that the U.S. government is doing “too much” to protect the environment. Americans are far more likely to say that the government is doing too little (50%), while 28% believe that the government is doing “about the right amount.”