The above image shows how the global biosphere changes over time. The Normalized Difference Vegetation Index measures the amount and health of plants on land, while chlorophyll a measurements indicate the amount of phytoplankton in the ocean. Land vegetation and phytoplankton both consume atmospheric carbon dioxide. As the seasons change, the patterns of life change as well. Plants thrive in the summer on land and in the oceans, and die or become dormant during the winter. Tropical areas respond more rainfall patterns than temperature. Over years of observation, the results of long-term climate change become apparent. By tracking these changes in the biosphere, scientists can study changes in the carbon cycle. (Animation courtesy the SeaWiFS Project, NASA/Goddard Space Flight Center, and ORBIMAGE)

back to: Carbon on the Land and in the Oceans: The modern carbon cycle