Question

In An Inconvenient Truth, a graph of atmospheric carbon dioxide shows a regular decrease in the amount of the gas once a year. What time of year does this happen?

Answer 1

The regular decrease in atmospheric carbon dioxide levels shown in An Inconvenient Truth occurs during the Northern Hemisphere's spring and summer seasons, from around March to September. This phenomenon is related to the photosynthetic activity of vegetation, especially in the Northern Hemisphere, where there is a greater amount of landmass supporting plant life. During these seasons, plants are actively growing and photosynthesizing, absorbing carbon dioxide from the atmosphere and reducing its concentration.