Why are CO2 levels higher in winter than summer?

Question

Besides the fact that we heat our homes in the winter.

Thanks....

Answer 1

The cold air keeps CO2 which is heavier then air, close to the surface of the ground. In the summer plants process CO2 as part of their growing process, turning it into energy and producing oxygen

Answer 2

As I know in winter the surface of the ground is cold, because there is no sunlight and this makes the weather near the earth cold too
Cold weather is heavier than warm weather (because of its density); the warm weather has already gone up.
In this situation there won't be the normal circulation of weather in warm days
In the other hand, cars, industries, people,... are polluting the air, which results a much polluted air which is very dangerous in cities like Tehran (I'm Iranian)
How ever this is only correct in a situation which there is no wind or rain …
Those answers about trees and plants may be correct too
But this seems to be more serious in large cities

Answer 3

As a pure guess I would think it's because all the tree's are bare and are not turning as much CO2 into Oxygen as they do in summer when they're full of leaves and in full bloom.

Answer 4

Plant activity, reducing CO2 in the summer..

Unfortunately it's nowhere near enough to make up for our activities.

This graph is illuminating. The little teeth are plants trying to stop global warming. The big surge upward is us burning fossil fuels.

http://scrippsco2.ucsd.edu/graphics_gallery/mauna_loa_record/mlo_record.html

We're kicking natures' butt on this one.

Answer 5

Less plants are active to convert it back.

Answer 6

trees and other green plants arent actively exchanging.