Reuters: Rising greenhouse gases have boosted rainfall in the Sahel region of Africa, easing droughts that killed 100,000 people in the 1970s and 1980s, in a rare positive effect of climate change, a study said on Monday. The report adds to debate about the causes of a greening of the Sahel region, south of the Sahara Desert from Senegal to Sudan. It said a continued rise in greenhouse gas emissions was likely to help more rainfall in the region in future. "Amounts of rainfall have recovered substantially,"...