What are three drawbacks of alternative sources of fossil fuels?

Of the three fossil fuels, for a given amount of energy released, coal produces the most carbon dioxide and natural gas produces the least. Coal and oil release sulfur dioxide gas when they burn, which causes breathing problems for living creatures and contributes to acid rain. I hope this helps!

Fossil fuels will run out eventually, they are dangerous to get to places(just imagine if a truck full of fuel got in a accident and spread fuel everywhere) , they are not good for the environment
Hope this helps:)