If the rise in carbon dioxide concentrations contributes to the increase in global warming threats, then what has led to the increase in global warming?

Answer choices:
- Greenhouse gases
 - movements in the earth's crust
 - Increase in carbon dioxide
 - Greenhouse gasses
 - forest is destroyed
 - Burning fuel and air
 - movement of tectonic plates
 - tectonic plates being pushed together

 

   Increase in carbon dioxide       