The 15 kilometer (9.3 mile) wide Great Green Wall project stretches over 7,775 km from Senegal on the Atlantic to Eritrea on the Red Sea. The aim was to curb the Sahara Desert's spread. But major challenges remain.
Two communities — one in Canada, one in the U.S. — share both a border along the St. Marys River and a toxic legacy that has contributed to high rates of cancer. Now the towns are banding together to fight a ferrochrome plant.