Mongabay: In a dramatic response to global warming, tropical forests in the high elevation areas of five continents have been "browning" since the 1990s. They have been steadily losing foliage, and showing less photosynthetic activity.
Scientists analyzed the forest cover by using satellites to measure sunlight bouncing off the surface of the earth, then determining the different surface types via reflection patterns. Areas with lush foliage where photosynthetic rates are high appear green, and areas with...