Chemistry

Forests in Europe, North America, the Caucasus, and Central Asia have expanded steadily over the last two decades, increasing by more than 25 million hectares — an area slightly larger than the United Kingdom — since 1990, a UN report says. In Europe alone, forested areas increased by 17 million hectares from 1990 to 2010, with the volume of forests growing by more than 430 million cubic meters annually, according to the Global Forest Resource Assessment 2010.

Corals are marine organisms living in compact colonies of many identical individual polyps. The group includes the important reef builders that inhabit tropical oceans, which secrete calcium carbonate to form a hard skeleton. Coral reefs form some of the most diverse ecosystems on Earth.

Think about the millions of tons of waste materials that are hauled away, buried or burned each day from landscaping and groundskeeping operations. This includes trees, shrubs, brush, lumber, asphalt and concrete, just to name a few.

The amount of dust in the Earth's atmosphere has doubled over the last century, according to a new study; and the dramatic increase is influencing climate and ecology around the world.