As petroleum is a non-renewable natural resource the industry is faced with an inevitable eventual depletion of the world's oil supply. The Hubbert peak theory suggests that after a peak in oil production rates, a period of oil depletion will ensue. Since virtually all economic sectors rely heavily on petroleum, peak oil could lead to a partial or complete failure of markets

The petroleum industry is the largest industrial source of emissions of volatile organic compounds (VOCs), a group of chemicals that contribute to the formation of ground-level ozone (smog). The combustion of fossil fuels produces greenhouse gases and other air pollutants as by-products. Some petroleum industry operations have been responsible for water pollution through by-products of refining and oil spills.