Fact 1: Gases released during the use of fossil fuels causes global warming.

Fact 2: Cars and factories burn fossil fuels, releasing nitrogen oxide gases and reactive organic compounds.

Given the two facts above, answer the question "Driving a car contributes to " with the following options: 
- dark matter
 - Quality of life
 - global warming
 - salty cashews
 - kinetic energy
 - lowered energy cost
 - expansion of the universe
 - survive


 

   global warming      