Guardian: Desmond Tutu, the Nobel peace prize winner and activist, has called for an international campaign to boycott mining companies, oil corporations and other businesses involved in the trade of fossil fuels. Writing exclusively in the Observer prior to this week's UN climate summit in New York, Tutu says the same approach that was taken by the 1980s anti-apartheid campaign, of which he was a leader, should now be adopted in the battle to halt global warming. "The most devastating effects of climate...