Environmental policy is among the many issues that American voters will soon consider as they cast their ballots in the 2020 presidential election, and for some of them it will loom large. According to a recent survey by Yale University and George Mason University researchers, for example, some two thirds of registered voters say they are worried about global warming and would support a carbon tax to combat it.

Republican President Donald Trump and Democratic presidential nominee Joseph Biden have offered voters vastly different ideas about how to tackle climate change, limit pollution, and protect endangered species.

For the first two years after Trump took office, National Geographic kept a running list of the changes his administration made to environmental