WELLSTON, Ohio — To Gwen Beatty, a junior at the high school in this proud, struggling, Trump-supporting town, the new science teacher’s lessons on climate change seemed explicitly designed to provoke her.So she provoked him back.When the teacher, James Sutter, ascribed the recent warming of the Earth to heat-trapping gases released by burning fossil fuels like the coal her father had once mined, she asserted that it could be a result of other, natural causes.When he described the flooding, droughts and fierce storms that scientists predict within the century if such carbon emissions are not sharply reduced, she challenged him to prove it. “Scientists are wrong all the time,” she said with a shrug, echoing those celebrating President Trump’s announcement last week that the United States would withdraw from the Paris climate accord.