A new series of NASA images illustrates how Earth's plant growth has changed over the past 11 years.

The global biosphere, or the sum of all ecosystems that support life on Earth, is in constant flux. The images show changes in chlorophyll, the green pigment in plants allows photosynthesis to occur, averaged over each year. Changes in land growth are shown as a vegetation index, a blend of the variation between the summer flourishes and the slow growth winter.

The NASA maps show dense vegetation areas on land as dark green and high concentrations of chlorophyll in the ocean as yellow. The highest vegetation index is found around the tropical regions near the equator. Chlorophyll is also abundant near the equator and near Earth's poles.