If you take a long enough view, then effects are negligible.
So, by “long term” do you mean 1 year, 2 years, 5 years, 25 years, 100 years, or what?
I think it important to realize that oil, natural gas, and other “fossil fuels” are natural products of the Earth. It sucks when we spill it all over the place, of course, but it’s not nearly as bad as some of the nuclear-toxic, man-made, don’t-even-look-at-it-or-you-might-die kinds of artificial compounds that we produce.
And it’s amazing how fast the Earth can recover from the “bad” things it produces itself. Look at volcanoes, undersea heat vents, hurricanes, wild fires, tornadoes, etc. They’re all destructive… and yet they are all also necessary to maintain the variation of life we see on this planet.