Here's a problem to solve: The burning of fossil fuels has increased the carbon dioxide content of the atmosphere. What is a possible effect that the increased amount of carbon dioxide is likely to have on our planet?

Among the 4 following options, which is the correct answer?

- A: A warmer climate
 
- B: A cooler climate
 
- C: Lower relative humidity
 
- D: More ozone in the atmosphere
 