Here are some quick facts about the pollution coming from fossil fuels.
Fossil fuels (coal, oil and natural gas) when burn create carbon dioxide (CO2) emissions that contribute to global warming, and also some air pollutants like nitrogen oxides, sulfur dioxide, volatile organic compounds, etc.
Fossil fuel burning is also responsible for the formation of acid rains, and acid rains are one of the most vicious contributers to environmental pollution, mostly in form of water pollution (acid rains increase the acidity of rivers, lakes and other water bodies).
The fossil fuel that mostly pollutes our planet is coal. Coal, when burned creates large amounts of coal ash. Coal ash is known to have extremely negative impact on air and water pollution.
Fossil fuels also contain some radioactive elements like uranium and thorium so they can also contribute to increased levels of radioactive pollution. These radioactive levels are not to be ignored because one study showed that during 1982, US coal power plants released 155 times as much radioactivity into the atmosphere as the infamous Three Mile Island incident.
Fossil fuels can also indirectly contribute to increased levels of pollution. For instance offshore oil drilling can cause big ocean pollution which can cause serious problems for many marine ecosystems.
Oil tanker accidents can also cause huge levels of pollution in form of oil spills like for instance the infamous Exxon Valdez oil spill. You all probably still remember what kind of environmental damage did Gulf of Mexico oil spill done to nearby marine environment.
Many countries in the world still lack the adequate laws that would limit the levels of pollution connected with fossil fuel burning. This is one of the reasons why world still fails to agree on new international climate deal.
Many environmentalists believe that the best way to force fossil fuel industry to reduce the levels of pollution would be in form of heavy taxes. Some energy experts fear that this would significantly increase average energy bill because renewable energy is still not ready to replace fossil fuels on global level.
Moving away from fossil fuels would no doubt significantly decrease the environmental pollution on our planet, but fossil fuels are sadly expected to remain dominant energy sources for at least next couple of decades.