About two years after Congress passed “the most important climate change act ever,” President Trump let the world know he was reversing hopes for U.S. leadership on the issue, a noted University of Toledo lecturer said Tuesday night.

Andrew Jorgensen, a professor emeritus of chemistry who has given as many as 300 talks a year on climate change to all sorts of groups, used the abrupt policy switch to explain how the issue has come to a virtual standstill on the global stage since President Trump took office in January.

Mr. Trump immediately withdrew America from the Paris Agreement adopted by 195 countries in 2015 and has since done a lot more to promote more use of climate-altering fossil fuels and reduce investments in wind, solar, and other sources of renewable power, he said.

Mr. Jor

See Full Page