“Oil has made and destroyed empires.”
Oil, along with its sister fossil fuels coal and natural gas, has given us a heretofore unimaginable degree of comfort, mobility and wealth of consumables with minimal effort. But this is coming to an end. Not just because oil emits climate-destroying greenhouse gases when it burns, but because - we are running out of it!
In the US, conventional oil extraction peaked and began to decline in the 1970s. Worldwide, conventional oil extraction began to stagnate around 2005. Oil prices surged. The more arduous process of extracting oil locked in rocks - “fracking” for shale gas and oil - became competitive, with the US in the lead. But shale wells require continuous drilling and eventually dry up.
If the climate issue unfortunately provides insufficient motivation for a rapid global renonciation of fossil fuels, their slow but irrevocable depletion may begin once again to bring nuclear energy to the fore as an indispensable energy alternative.
For a fuller treatment of this issue, see And you thought CO2 was the only problem fossils had us facing?” posted by Voices of Nuclear.
On relative safety of energy sources, look here.