Determine the overall effect that plants have on the atmosphere. Add carbon dioxideRemove carbon dioxideAdd oxygenRemove oxygenI'm not sure

Plants have a significant impact on the atmosphere in several ways:

1. Remove Carbon Dioxide: Through the process of photosynthesis, plants absorb carbon dioxide (CO2) from the atmosphere. This is a crucial process that helps to reduce the levels of CO2, a greenhouse gas that contributes to global warming.

2. Add Oxygen: As a byproduct of photosynthesis, plants release oxygen (O2) into the atmosphere. This is essential for the survival of most life forms on Earth that require O2 for respiration.

3. Add Carbon Dioxide: It's important to note that while plants do absorb CO2 for photosynthesis during the day, they also respire just like animals, releasing CO2 back into the atmosphere, but this is significantly less than the amount they absorb.

4. Remove Oxygen: Similarly, during respiration, plants use up oxygen, but again, this is less than the amount they produce during photosynthesis.

So, overall, plants help to decrease carbon dioxide levels and increase oxygen levels in the atmosphere, contributing to a healthier and more sustainable environment.