higher levels of oxygen in the atmosphere lower levels of ozone in the atmosphere higher levels of carbon dioxide in the atmosphere lower levels of nitrogen in the atmosphere
I am hesitating between 4 options to answer the following question, which option should I choose?
Question: The average temperature of the surface of Earth has increased approximately 1°C in the past century. Which reason best explains this increase in temperature?
Possibilities:
- higher levels of oxygen in the atmosphere
- lower levels of ozone in the atmosphere
- higher levels of carbon dioxide in the atmosphere
- lower levels of nitrogen in the atmosphere

higher levels of carbon dioxide in the atmosphere