The modern world wouldn’t be what it is without fossil fuels.
The Industrial Revolution—the very beginning of our prosperous, technologically advanced society—couldn’t have happened without them. Today, cars and planes, homes, and industries all rely on this abundant energy source. It’s not an exaggeration to say we’ve built our society around them.
Of course, we’ve known all along that our reliance on fossil fuels has a downside. The pollution created by their smoke was plain to see—and often to smell. But in the last half-century or so, we’ve discovered an even bigger problem: global warming. When we burn fossil fuels, they release heat-trapping greenhouse gases into the atmosphere.
Because of our heavy fossil fuel use, the planet is already hotter than at any time in recorded history. Heat waves, wildfires, droughts, and storms have all grown more destructive as a result. And they will get worse still if we don’t curb our fossil fuel use in the future.
There are three main kinds of fossil fuels: coal, oil, and natural gas. These substances are formed from the remains of plants and tiny creatures called plankton that lived millions of years ago. As they grew, they captured and stored energy in their bodies from sunlight. They also absorbed carbon dioxide (CO2) from the atmosphere.
When they died, their remains sank to the bottom of the ocean. Layers of sediment built up over them until they were deep underground, subjected to intense pressure and heat. Under these forces, the organic matter in them gradually broke apart and transformed. Plant matter turned into coal and plankton into oil (also called petroleum) and natural gas.
These materials contain all the stored energy of the living organisms they once were. Burning them releases all that trapped energy. For over 200 years, humans have relied heavily on fossil fuels as an energy source. Today, 80% of all the energy used in the U.S. comes from them.
If you’re like most people, you use fossil fuels many times every day. For instance, you drive a gas-powered car, the gasoline it burns comes from oil. If you travel on a plane or boat, it also most likely runs on petroleum-based fuel. At home, you may rely on natural gas for heating water or your home, cooking, and even drying clothes. And there’s a good chance the electricity you use comes from burning natural gas or coal.
You’re also probably using products made from fossil fuels, especially oil. All sorts of common goods, including plastics, fertilizers, lubricants, and cosmetics, are petroleum-based. The paint on your walls, the asphalt in your driveway, and the shingles on your roof are all very likely to be petroleum products.
Most industries rely on fossil fuels for energy. Roughly 18% of all fossil fuels used in the U.S. are burned as fuel for industrial purposes. Industries that use fossil fuel energy include manufacturing, agriculture, forestry, fishing, mining, and construction. These industries also rely on fossil fuels for products such as fertilizers, lubricants, solvents, and building materials.
Although industry is a big consumer of fossil fuels, it’s not the biggest. More than one-fifth of all fossil fuels in the U.S. are burned to generate electricity. And transportation accounts for over one-fourth of the nation’s fossil fuel use.
Unfortunately, burning fossil fuels doesn’t just release energy. It also releases all the carbon the ancient organisms stored in their bodies. The carbon mixes with oxygen in the air to form carbon dioxide (CO2), the main greenhouse gas responsible for global warming.
And this isn’t the only harmful compound produced. Burning fossil fuels also creates particulate matter, or soot—tiny black particles that damage your lungs when inhaled. It releases harmful sulfur dioxide and nitrogen oxides that react with sunlight to form smog. All these chemicals pollute the air, hurting both humans and wildlife.
Fossil fuel deposits are most often found deep underground or trapped within layers of rock. To use them, we need to dig or drill into that rock and extract the fuels. Unfortunately, this process can be both dangerous and damaging to the environment.
There are two main methods of mining for coal.
Underground mining means using heavy machinery to burrow deep into the earth’s surface. Miners climb down into these deep pits and hack out the underground coal by hand. This is a very dangerous job. Mines can collapse and miners may encounter trapped pockets of poisonous or explosive gases. They also suffer lung damage from long-term exposure to coal dust. And the digging of deep mines damages wildlife habitats.
Surface mining, or strip mining, tears away layers of soil and rock to get at the coal deposits below. This process poses much less risk to miners, but it does even more damage to the environment. It tears away trees and topsoil from large areas of land, leaving them barren. It also exposes minerals and heavy metals formerly trapped underground. These harmful chemicals wash into nearby streams and aquifers, making the water undrinkable.
In some cases, strip mines can also be used for oil extraction. While most oil deposits are deep underground, oil can also be trapped in sand and rock closer to the surface. Strip mining this rock, known as oil shale, is just as destructive as strip mining for coal.
The main way to extract oil and natural gas is through drilling. Huge drills bore down into the layers of rock to reach the deposits of oil or gas below. This can happen either on land or on the ocean floor.
In both cases, the process of exploring and drilling for oil disrupts local ecosystems. On land, it involves clearing all the vegetation from an area. Underwater, it displaces fish and other sea creatures. Also, wells can leak, releasing oil or gas into the environment. Gas leaks are a particular problem since natural gas is mostly methane, a potent greenhouse gas.
A newer method of extracting oil and gas is hydraulic fracturing or fracking. This means blasting large amounts of water mixed with toxic chemicals into cracks in rock layers. The pressure of the water splits apart the rock, allowing the oil and gas to escape. Fracking produces large amounts of contaminated wastewater, which companies generally dispose of by injecting it back into the ground. This process can contaminate groundwater supplies and, in some cases, cause earthquakes.
When fossil fuels first come out of the ground, they usually contain other chemicals that don’t make good fuel sources. So, after extracting fossil fuels, companies must process them to remove these chemicals. This is called refining.
Oil refining is particularly complicated. It involves heating the crude oil that comes out of wells until it turns to vapor. Different chemicals within the oil vaporize at different temperatures. Each one gets extracted, recondensed, and purified to form a variety of products, including:
Refining fossil fuels goes hand-in-hand with transporting them. First, they must travel from the mine or well to the refinery. Crude oil and gas often flow from place to place through large pipelines. Fossil fuels can also travel on large tanker ships, trucks, and trains. And when they leave the refinery, similar methods carry them to the places where they’ll be used.
Like extraction, fossil fuel refining and transportation can harm the environment. Pipelines can leak oil or gas. Spills can also occur as a result of truck, train, or tanker crashes. The refining process pollutes the air, and refineries' wastewater can also pollute water. And because the ships and trucks that carry fossil fuels usually run on them as well, they’re a source of greenhouse gas emissions.
One problem with fossil fuels is that they’re not renewable. Because they take millions of years to form, we can’t just make more of them when we use up what we have. However, fossil fuel companies are pretty good at finding and extracting new supplies. So, at present, we’re not in any danger of running out.
What we are running out of is time. Because every day that we keep using fossil fuels, they do more damage to the environment. At every stage of their use—mining, processing, and burning—fossil fuels harm our health and the health of the planet. And the longer we continue to rely on them, the greater the danger becomes.
Extracting, refining and burning fossil fuels release a variety of chemicals that harm human health. These include soot, sulfur and nitrogen oxides, and leaked methane. All these chemicals pollute the air we breathe, increasing our risk of respiratory diseases. Pollution poses the greatest risk in low-income communities, which are usually closer to fossil fuel pipelines, refineries, and power plants.
The sulfur and nitrogen oxides created by burning fossil fuels don’t just pollute the air. They also react with water and other substances to form acid rain. Acid rain harms plants, trees, fish, and other wildlife. It can also damage buildings and other structures.
Fossil fuel use pollutes the water in a variety of ways. These include oil spills, runoff from strip mines, wastewater injection from fracking, and wastewater from refineries. Nitrogen oxides produced by burning fossil fuels also contribute to water pollution. They precipitate out of the air and wash into waterways, changing the water chemistry in ways that threaten aquatic life.
Like air pollution, water pollution has an outsized impact on low-income households and people of color. Small, low-income communities are much more likely than other communities to lack access to safe drinking water. And they’re less likely to have the resources needed to bring their water system up to par.
Plants that burn fossil fuels use large amounts of freshwater for cooling. This drains local water supplies, leaving less for farming and other uses. Some power plants return the water to rivers, lakes, and oceans, but this causes problems as well. The water leaves the plant much hotter, and it contains lower levels of dissolved oxygen. This threatens the health of fish and other water-dwelling creatures.
The biggest threat fossil fuels pose is their effect on global temperatures. Fossil fuels are the largest source of greenhouse gas emissions responsible for global warming. This includes CO2 and nitrous oxide (N2O) from burning fossil fuels and methane leaked from gas wells and pipes.
Fossil fuels also worsen global warming in another way. When fine particles such as soot land on snow or ice, they make their surface darker. This causes it to absorb more heat from sunlight and melt faster. As the snow cover vanishes, the land surface gets darker still, absorbing heat even faster. This is one of the reasons ice and snow in many areas now melt earlier and faster, reducing freshwater supplies.
Climate change is the greatest environmental threat we face today. It increases the severity of all kinds of weather disasters, including storms, droughts, floods, and wildfires. It’s melting icecaps and glaciers, causing sea levels to rise. And much of the increased CO2 in the atmosphere is being absorbed into the ocean, making it more acidic. This threatens various kinds of wildlife, including fish and coral reefs.
Climate change is also an environmental justice issue. Historically, wealthy nations in Europe and North America have been the heaviest users of fossil fuels. Yet it’s lower-income countries and communities that are paying the highest price for the resulting global warming.
Countries near the equator are suffering from more extreme heat. Indigenous peoples in the Arctic, which is warming faster than other parts of the globe, are losing the wildlife crucial to their traditional way of life. Island nations and low-lying coastal areas, such as Bangladesh, are at risk from sea level rise.
Even within the U.S., low-income people face the greatest danger from extreme weather. They have higher rates of illness and death from extreme heat. Low-income communities are more likely to suffer damage from natural disasters. And they’re less likely to have the resources to rebuild afterward.
At this moment, the answer is yes.
Although alternative power sources can replace fossil fuels in many cases, they don’t work for everything yet. For instance, electric vehicles are great for passenger travel, but they don’t work well for long-haul trucking. The best batteries available today don’t have enough power to carry heavy loads over long distances. Likewise, today’s airplanes are dependent on jet fuel made from petroleum.
Some industrial processes also can’t currently work without fossil fuels. The blast furnaces used to make steel need to reach temperatures of around 1,100°C. The kilns used for producing cement must get even hotter, around 1,400°C. Right now, it is difficult to reach these temperatures without burning fuel, which usually means fossil fuel. Though innovations are being made to get there, though few exist today, like a solar-powered steel mill in Colorado.
But even if these industries require fossil fuels now, that doesn’t mean they always will. If we want to stop climate change, we’ll need to find alternatives. And we’re already beginning to explore some, such as hydrogen and biofuels. A Swedish company is testing a process to manufacture steel with renewable electricity and hydrogen. A Finnish company has created a plant-based jet fuel. And Daimler is working on long-haul trucks powered by hydrogen fuel cells.
Fossil fuels serve many different purposes, and there’s no single alternative that can do all the same jobs. To replace them, we’ll need to use a variety of clean energy sources.
For generating electricity, wind and solar energy are good alternatives. In fact, both are already cheaper than fossil fuels for this purpose. And, as these power sources make the grid greener, it becomes possible to power homes and cars cleanly with electricity.
Hydrogen, as noted above, shows great potential for use in industry and transportation. But to fight climate change, it needs to be green hydrogen, produced without the use of fossil fuels. Ramping up renewable power production will be key to making hydrogen energy sustainable.
Another idea we’re just beginning to explore is renewable natural gas or biomethane. This is methane emitted by sources such as landfills and animal waste pools on farms. Since methane is a powerful greenhouse gas, letting it escape into the atmosphere is very harmful. Capturing it and burning it releases CO2 instead—still a greenhouse gas, but a less potent one. That reduces its climate impact while producing energy at the same time.
Fossil fuels play a huge role in the world economy today. Keeping that economy working without them won’t be easy. But we don’t have a choice about it. Phasing out fossil fuels is the only way to prevent catastrophic climate change that will destroy society anyway.
Moreover, a future world powered by 100% renewable energy will be better for everyone than the world of today. Without fossil fuels, the air and water will be cleaner. Fewer people will suffer from respiratory illnesses. There will be no new mines to scar the landscape, and ecosystems already damaged by mining may begin to recover.
This environmentally sustainable world is possible if we all work toward it together. Companies will need to adopt alternatives to fossil fuels where they can, as well as continue to develop new and better alternatives. World governments will have to adopt policies that discourage fossil fuel use and steer people toward renewable energy. And individual consumers like you and me can do our part by eating sustainably, traveling sustainably, conserving energy, and switching to renewable power.
With a little effort from everyone, we can build a better world for the future.