Reuters: Environmental groups driving the a divestment movement argue that most fossil fuels must not be burned if the world is to avoid the worst effects of climate change - a threat to the value of energy companies which own coal, oil and gas reserves. The movement is trying to repeat the success of a divestment campaign which decades ago pushed South Africa to dismantle the apartheid system. Fossil fuel divestment has gained some traction with U.S. city pension funds, but is running into legal uncertainty...