OpenTreeMap is helping cities figure out where all the trees are, so they can better judge the environmental and public health impacts of a well-planted city. Here's a hint: The impacts are huge.

Find a tall stick. That and one good eye are all the tools you’ll need. With the stick in hand, walk exactly 11 paces from the base of the tree and mark the spot by driving the stick into the ...

A new map shows forest height around the globe and will improve estimates of how much carbon is stored in trees.