Detailed Instructions: Given a scientific question and its correct answer, generate supporting facts for the answer. This supporting fact can be an explanation for the answer to the given question.
Q: Question: What is a byproduct from the combustion of fossil fuels like coal and gasoline? Answer: nitrogen dioxide
A:
The brown color is from nitrogen dioxide gas. Nitrogen dioxide is a byproduct from the combustion of fossil fuels like coal and gasoline.