a source of something releases that something & gases released during the use of fossil fuels causes global warming ->  the use of fossil fuels is a source of gases that cause global warming  worldwide means across the entire earth & global warming is when worldwide temperature increases ->  global warming is when temperatures across the entire earth increase  global warming is when temperatures across the entire earth increase & temperature increase is a kind of impact ->  global warming impacts the entire earth  global warming impacts the entire earth & if something impacts the entire earth then that something has a significant impact on the earth ->  global warming has a significant impact on the earth  global warming has a significant impact on the earth & earth's atmosphere is a part of the earth ->  global warming has a significant impact on eath's atmosphere  the use of fossil fuels is a source of gases that cause global warming & global warming has a significant impact on eath's atmosphere ->  the use of fossil fuels is a source of gases that significantly impact the earth's atmosphere  the use of fossil fuels is a source of gases that significantly impact the earth's atmosphere & something comes from a source of that something -> gases that significantly impact the earth's atmosphere come from the use of fossil fuels