WASHINGTON (Reuters) - Donald Trump’s promise to gut U.S. environmental regulations and revive the controversial Keystone XL oil pipeline if elected president is a nightmare for green groups, but it may be a dream come true for their fund-raisers. The country’s biggest environmental groups say the Republican White House hopeful’s pro-drilling and anti-global warming positions have sparked a record wave of donations and volunteer recruitment that could revitalize U.S. green advocacy. Trump has said he would revive the coal industry, pull the United States out of a global climate pact and expand oil drilling.  “We couldn’t have asked for a more powerful motivator than Donald Trump,” Sierra Club Executive Director Michael Brune said. Brune said a spring email blast about the New York businessman to the San Francisco-based group’s members yielded $25,000 in donations, more than twice as much as projected, along with 15,000 new volunteers. The club’s Political Committee, which works directly on projects to engage voters during the election, has raised more than $62,000 this year, compared with just $22,000 at this point in the 2012 election, according to the filings with the Federal Election Commission.     The Washington-based League of Conservation Voters has also gotten a boost. Officials said its annual fund-raising dinner this week pulled in a record haul, which they would not disclose, after the group also used Trump as a focal point of its donor outreach. “It’s been a long time since there has been someone that our movement has so universally wanted to stop,” said spokesman David Willett.  The league’s Voters Action Fund, meanwhile, has raised more than $610,000 in donations so far this year for election-related work, more than triple what it pulled in during the same period of 2012, and more than double that of 2008, according to federal filings. Trump has long signaled his belief that global warming is a hoax. Last month he outlined plans to sweep away environmental regulations ushered in by the Obama administration, scrap the Paris Climate Accord, and revive the Keystone XL - moves that would reverse years of gains by the green movement. A spokeswoman for Trump’s campaign did not immediately respond to a request for comment. NextGen Climate, a San Francisco-based environmental advocacy organization founded by billionaire activist Tom Steyer, has called Trump’s agenda “frightening.” But its efforts were also getting some traction from the candidate’s rhetoric.  The group, which has featured Trump in its TV ads to drive voter turnout, said it had seen a 127 percent increase in clicks on its social media postings that mention the candidate compared with those that do not. “There is no question that voters are very engaged when it comes to fighting back against Trump,” said NextGen spokeswoman Suzanne Henkels. Ben Avery, associate fund-raising director of the Sierra Club’s Northwest chapter, said he was happy about the increase in donor support this year but was vexed by the reason behind it. “Bad news is good news for fund-raising,” he said.  