Farther west in Africa, in Congo, Brazzaville, scientists have found a remarkable peat bog - a vast expanse of decaying plant material. The discovery could tell them about the whole planet's atmospheric history. It is a rare, tropical peat bog. It's the size of Pennsylvania. The thick layer of carbon it traps may offer clues to what was in the air over 10,000 years ago. Dr. Simon Lewis of the University of Leeds led the research team, and he joins us now to tell us about this little-studied region. Welcome to the program.