Climate Desk: This week the exiled head of the Syrian opposition movement said he would meet representatives of President Bashar al-Assad in Geneva, a promising turn for a conflict that has left 100,000 dead, including many civilians, since spring 2011. It has been a long, bitter battle, but for many Syrians one root of the violence stretches back to several years before al-Assads troops began picking off anti-government protestors. Beginning in 2006, a prolonged, severe drought decimated farmland, spiked food...