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

Fact 2: Global warming has great effect on crops and weather conditions around the world.

Given the two facts above, answer the question "What can have a long term effect on crops and weather conditions around the world?" with the following options: 
- electromagnetic energy
 - A farmer irrigating his crops
 - deforestation
 - Nitrogen in the soil
 - Temperature
 - Use of fossil fuels
 - Burning fuel and air
 - A windy day


 

      Use of fossil fuels   