How can you explain that we do not experience a lack of oxygen during the winter?

In winter, we do not experience a lack of oxygen due to the fact that there is enough oxygen in the air. Despite the fact that it is winter, and the trees have dropped their foliage, and the process of photosynthesis does not take place. In other parts of our planet, it is warm and there trees are producing oxygen at full speed. And thanks to the winds, this oxygen reaches us. Also, do not forget about the lungs of our planet. Equatorial forests that are always green and always produce oxygen.