Yearly CO2 Changes

Most recent answer: 02/08/2012

Q:
Can carbon dioxide levels in the atmosphere decrease and increase throughout the year?
- Chris (age 8)
FL,USA
A:
Yes, the CO2 level oscillates every year, as you can see in graphs on this site:
The reason has to do with the seasonal cycle of plant growth and decay. Since there's more land in the northern hemisphere, the opposite seasonal changes in the two hemispheres don't cancel out.

Mike W.

(published on 02/08/2012)