The American public's level of worry has ebbed and flowed in tandem across the six environmental threats over the past 21 years (2000 - 2021). Although degrees of worry have shifted over time, the rank order has remained largely consistent, with water pollution outpacing all other threats.

• Of six environmental problems facing the U.S., Americans remain most worried about those that affect water quality. Majorities express "a great deal" of worry about the pollution of both drinking water (56%) and rivers, lakes and reservoirs (53%).
• Fewer, though still substantial minorities ranging between 40% and 45%, express a great deal of concern about the loss of tropical rain forests, global warming or climate change, air pollution, and the extinction of plant and animal species.
• The latest figures show significantly lower levels of worry than in 2000 on all issues except global warming, which is roughly on par today with 2000 after some fluctuation in the interim years. 
• 41% percent of Americans rate the overall quality of the environment in the U.S. as "excellent" or "good," and 59% say it is "only fair" or "poor" -- both of which are essentially unchanged from the past several years' readings. Biden's election has resulted in a 26-point increase in Democrats' view that the quality of the environment is getting better. At the same time, Republicans have become less likely (by 12 points) to say it is improving.