From that, scientists can directly calculate how much carbon has been absorbed. To measure tree height around the globe, Lefsky used lidar data from a satellite orbiting 600 kilometers above Earth.

Mark this point on the stick, then measure the distance to the ground. The measurement you get in inches will be roughly the same as the height of the tree in feet.

Physicists like to share the legend of a professor who asked students how they might determine the height of a building using a barometer. The story goes on to list some of the ways you might do ...