Voice of America: A bipartisan advocacy group is calling on the United States to lead the effort to protect tropical forests around the world as a way to combat global warming. The Commission on Climate and Tropical Forests is pushing for the Senate to make deforestation a centerpiece of its climate bill. Carbon dioxide pollution also comes from forests converted to farmsTropical forests are home to more than half of all the animal and plant life on the planet. But 17 percent of the world’s …