Young climate activists outside the White House in September. (Jahi Chikwendiu/The Washington Post) Bruce Westerman, a Republican congressman from Arkansas, has a plan to help save the planet — one he thinks may also help save his party. His proposal, which calls for planting a trillion trees to suck carbon dioxide from the atmosphere, was warmly received last month when House Republicans gathered to discuss their policy agenda heading into the 2020 elections. After years of denying that the planet was growing hotter because of human activity, an increasing number of Republicans say they need to acknowledge the problem and offer solutions if they have any hope of retaking the House. In poll after poll, large numbers of young and suburban Republican voters are registering their desire for climate action and say the issue is a priority. And their concern about climate change is spreading to older GOP supporters, […]