WHAT'S INSIDE: ENVIRONMENTAL SCIENCE
The world's forests hold some of its most precious natural resources -- its trees. Sustainable forestry encourages attention to the forests' long-term health so they retain their value.
If you've ever seen a geyser letting off steam or witnessed a fuming volcano simmering under pressure, you know that the interior of the Earth is really hot. So where does all that heat come from, and is there any way to harness it?