How does the earth breathe CO2?

This graphic by a researcher at the Max Planck Institute shows how plants on Earth take in and release carbon with each season.

The Earth appears to be inhaling and exhaling in new graphics that reveal the process of absorbing and releasing carbon as the seasons change. The continents in the graphic appear to collapse in the summer, showing when and where plants grow and trees take in carbon dioxide (CO2) from the atmosphere. Come winter, the continents seem to swell, revealing a time when plants die and carbon is released.

The change is most pronounced in temperate regions such as Europe and North America, where seasonal differences are most pronounced. The regions at the equator do not change much throughout the year. Meanwhile, some sparsely vegetated desert regions do not store or release much carbon.

The data for the rendering comes from satellite observations and hundreds of carbon-monitoring stations around the world, says Markus Reichstein, director of the Department of Biogeochemistry at the Max Planck Institute in Germany. Reichstein shared the graphic on Twitter on January 6.

What is shown in the graphic is an important part of the carbon cycle or the flow of carbon through the planet. Carbon can be released into the atmosphere through decomposing organic matter and through the erosion of soil containing carbon compounds. In contrast, carbon can be sucked up by oceans and trees. Plants use carbon in photosynthesis.

Carbon can be released into the atmosphere through decomposing organic matter.

The importance of trees is clearly reflected in the graphic. Tree-packed places like the Amazon in Brazil and the forests of Eastern Europe suck up large amounts of carbon in the southern and northern hemisphere summers, respectively. The graphic doesn't include oceans because oceans absorb a lot of carbon but there is no discernible seasonal pattern.

According to Reichstein, climate change is changing plant growth patterns globally, so carbon flows in and out of the biosphere are also changing. Those changes are too small to show graphically, but will have different effects in different places. For example, longer and warmer summers in the Northern Hemisphere can be good for plant growth. But with warmer temperatures not accompanied by rain, as in much of the western US, climate change could limit tree growth.

"This carbon cycle and how it changes from month to month tells us a lot. Basically, the graphic shows how important it is to protect the carbon sinks," said Reichstein. Recent research has found that the Amazon, one of the largest carbon sinks on the planet, recently releases more carbon each year than it absorbs due to deforestation and wildfires.