A UN-led pilot scheme hopes to highlight how trees can help people in arid zone, considered to one of the most hostile habitats on the planet.  The Food and Agriculture Organization (FAO) Acacia project's goal is to show how trees provide,...

China built its famous Great Wall to keep out marauders. Now, millennia later, a "Great Green Wall" may rise in Africa to deter another, equally relentless invader: sand. The proposed wall of trees would stretch from Senegal to Djibouti as part of a plan to...