In what season is there enough oxygen?

In winter, due to the decrease of leaf photosynthesis, why people don't feel any change in oxygen in winter? Because of the different climatic conditions in different parts of the earth, the plants on the surface of the earth are unevenly distributed, so the degree of photosynthesis is different. There is no seasonal change near the equator, and plants can carry out photosynthesis all year round to produce oxygen. The climate in the southern hemisphere and the northern hemisphere is just the opposite. As far as this area is concerned, the oxygen produced has decreased. However, at this time, it is summer in the southern hemisphere. Because the earth is constantly moving and the oxygen content in the air can be adjusted, the oxygen in the atmosphere is basically balanced all year round and will not be significantly reduced because of the fallen leaves of plants in winter. People naturally don't feel any changes in oxygen in winter.

But when a person's vital capacity is fixed, the amount of gas coming in is also fixed. The final oxygen content is directly proportional to the air pressure, and the higher the air pressure, the more oxygen content, and vice versa. High altitude, low air pressure and low oxygen content. On the other hand, the sultry weather in summer will make you feel short of breath, which is also due to the low oxygen content in the air pressure.