How GM Invented Planned Obsolescence It all started with a struggling auto company in the 20s.

Find out what nitrogen oxides (NOx) are, why they are a serious environmental concern, and what role they play in the Volkswagen diesel engine scandal.

Pine trees are one of the most common coniferous species in North America. Learn how to identify the types found in the United States and Canada.

Learn how trees use massive amounts of water through the process of transpiration for the benefit of themselves and the Earth.

What can you learn from a tree's leaves? Discover how leaf shapes, edges, patterns, and more can help you identify a tree in the forest.

There are many preconceived notions about tree root systems. Tree roots are sensitive but tougher than expected. They just need appropriate care.