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

Fact 2: Carbon dioxide is produced by the burning of fossil fuels such as coal, oil and natural gas.

Given the two facts above, answer the question "What does burning oil cause?" with the following options: 
- Clean water
 - Dehydration
 - More oil
 - chemical reaction
 - Global warming
 - forest is destroyed
 - An ice age
 - hyperthyroidism


 

     Global warming    