system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: If trees are technically “hibernating” during winter, how are they continuing to turn our CO2 into oxygen?
gpt
It depends on what kind of trees you're talking about.

Deciduous trees, i.e. those that lose their leaves during the winter, absolutely do not convert CO2 into O2 during the winter months. This is because photosynthesis is required for the carbon cycle, and that is not possible without chlorophyll, which is present only in the leaves. Deciduous trees truly do "shut down" during the winter.

Fir and pine trees, and other evergreen plants, do continue to photosynthesise, but at a much reduced rate due to the low availability of sunlight. So they do convert CO2 into O2, but at a much reduced rate.