In the carbon cycle, it's not just about the individual tree-the entire forest plays a role. Leaves take in carbon dioxide, converting it to sugar, which is carbon-based. Some of the sugar is used immediately for energy, converted back to CO2, and released into the atmosphere. The rest is stored in living wood or dead matter, such as fallen leaves and branches. Old-growth forests, in particular, store vast amounts of carbon while continuing to absorb CO2.
Climate change holds the potential to profoundly affect epidemiologic patterns, and vector biologist Andrew Githeko says malaria is particularly sensitive to this upheaval.
So far, rational environmental arguments have largely kept Utah's tar sands, which contain an estimated 12 billion to 20 billion barrels of oil, in the ground. Rising oil prices, however, may soon erase these historic constraints, just as they have done in Canada.
Nanomaterials have a much higher surface-to-mass ratio, and while this makes them good for such purposes as water filtering, it also could cause them to interact with body cells that their tiny size allows them to infiltrate.
Jeppe Blak-Nielsen has his own very specific reason for appreciating windmills: "Whenever the turbines at Middel-grunden are running," the Copenhagen yachtsman says, "I know the wind is perfect for sailing."