United Press International: Fewer than half of British voters believe human activity is responsible for global warming, a poll released Saturday by The Times of London said. Only 41 percent of those surveyed said they think climate change is underway and human activity is to blame, while 32 percent said they were unsure. Another 15 percent say the world is not getting warmer, while 8 percent said climate change is environmentalist propaganda. Conservative voters are less likely to say human activity is …