The Trump administration’s top air and climate adviser at the EPA for the past two years is resigning effective today, according to a Feb. 7 resignation letter sent to the White House and obtained by Bloomberg Environment.

Mandy Gunasekara said in her resignation letter to President Donald Trump that she planned to launch a new organization to support “the many energy, regulatory and economic successes” of his energy and environmental agenda, which is likely to come under intense scrutiny...