Data suggests fossil fuels are the dirtiest and most dangerous energy sources

The world derives more of its energy from oil than from any other resource

Coal and gas are second and third, respectively, in terms of where the bulk of the world’s energy consumption stems from. These interactive charts can help you visualize where the world sources the most of its energy.

Explore which sectors produce the most greenhouse gas emissions by country

As of 2023, the energy sector, including electricity and heating, accounts for the largest share of greenhouse gas emissions. The 10 largest greenhouse gas-emitting nations account for two-thirds of global emissions, with the world's top three—China, the US, and India—contributing 15 times more than the bottom 100.

Methane leaks during natural gas processing reduce the gas's overall cleanliness

Natural gas is advertised as a cleaner fossil fuel because it emits 50% less carbon dioxide than oil and coal when burned. Supporting analysis only considers end-use combustion and excludes total emissions generated by extraction, shipping, and processing.

A breakdown of global electricity generation in 2025, led by coal power plants

Fossil fuel plants generated 57% of global electricity, with the remaining power produced by clean energy sources, led by hydroelectric power at 14.0%. Roughly equal amounts of generation were provided by nuclear (8.9%), solar (8.7%), and wind (8.5%) power.

Nuclear power supplies almost half of US carbon-free energy

As of 2023, nearly 20% of US electricity comes from nuclear power, but most reactors were built from 1971 to 1990. Expansion slowed due to safety concerns, high costs, and competition from natural gas.

The fracking industry has created hundreds of thousands of jobs since 1949

The method of extracting fossil fuels from shale rock formations has saved Americans an estimated $23B annually in energy costs. Every year, fracking generates billions of gallons of wastewater and causes methane—a greenhouse gas that is over 25 times more potent than carbon dioxide—to leak into the atmosphere.

Heat is the leading cause of death in natural disasters

Floods are a distant second, followed by hurricanes. That's according to data reported by the National Oceanic and Atmospheric Administration.

During emergencies, backup diesel generators in data centers emit substantial pollution

During power outages or when the power grid is at insufficient capacity, these generators emit 200 to 600 times more nitrogen oxides—a greenhouse gas—than natural gas plants, as well as fine particulate matter linked to respiratory disease.

Where radon comes from and why it may be the most dangerous source of radioactivity

Released from underground bedrock before passing through soil, this radioactive gas is produced from the decay of uranium, thorium, and radium and accounts for about half of all human exposure to radiation. It is the leading cause of lung cancer among nonsmokers and can build up in enclosed spaces such as buildings without proper ventilation to dilute the gas.

Why decarbonizing the entire electric grid is impossible with its current infrastructure

Fossil fuel plants can be built anywhere and have thus typically been built near highly populated areas, such as coastal cities, where electricity demand is high. However, certain renewable resources operate most efficiently in specific regions, such as wind turbines in the Midwest, and therefore require substantial transmission infrastructure to be constructed to transport the generated electricity.

Some renewable energy sources may weaken the resiliency of electric grids by removing outage buffers provided by coal- and natural gas-fired plants, which provide the system with more time to find a new power source if a plant goes down.

Renewable energy basics

Discover the many benefits to using renewable energy resources, but what is it exactly? From solar to wind, it’s the fastest-growing source of energy in the world – and how we can use it to combat climate change.

Demystifying the claim that crude oil is inorganically created and a renewable resource

The abiogenic petroleum theory holds that fossil fuels originate in Earth's mantle and are constantly replenished, rather than formed by microorganisms over millions of years. While inorganic chemical processes can produce simple hydrocarbons, the range of complex molecules found in crude oil suggests an origin from a diverse set of organisms. Isotope analyses of these molecules also support the model that they originated from living things that preferentially take up certain isotopes over others.

View an illustrative guide to climate change for kids

While climates have changed throughout Earth's history, they are now changing faster than usual, driven by the burning of fossil fuels and the release of greenhouse gases, which trap more of the sun's radiation.

The surprising world of coal seam fires

Hundreds of coal seam fires are actively smoldering around the world at any given time, including some that have stayed lit for centuries. These fires have occurred naturally for millions of years, lit atop deposits of coal in the earth. Dive into...

Large oil companies knew about the impact of carbon emissions since the ’70s

PBS Frontline’s The Power of Big Oil reveals how industry giants like Exxon and Shell were researching climate change in the 1970s but then funded denial campaigns—using internal science to sow public doubt for decades.

Among renewable sources, geothermal rivals hydropower in lifetime cost

As of 2024, the levelized cost of energy—the average cost per unit of energy over the lifetime of a power plant—for geothermal power is surpassed only by solar photovoltaic and onshore wind. Geothermal's LCOE has remained relatively unchanged since 2007, with significant decreases held back by significant upfront installation costs.

Air pollution in war-torn Iran unleashes invisible toxic threats

Burning oil depots and bombed buildings are endangering the health of millions of people during the 2026 attacks. Heavy metals from munitions and other damaged materials are going airborne, but the exact health implications depends on dose, wind currents, and other factors including preexisting health conditions.

How fusion—which releases energy when two lighter atoms combine to form a heavier atom—differs from fission

Ranking the most expensive appliances on your electricity bill

Energy costs have gone up amid war and inflation. Here's a breakdown on the cheapest and most expensive appliances in your home to help you lower your bill.

What fuels the sun?

The sun is our biggest source of heat and light, but how does this massive powerhouse continue to produce such amazing energy? Basically, it's a fusion reactor. At its core the sun produces all that solar energy through hydrogen fusing and converting into helium, over and over again. Learn more about the entire amazing and explosive process here.

Utah is the ‘greenest’ state to die in—determined by burial emissions and green options

This map ranks each US state based on accessible, sustainable burial services and recent emissions from people’s burial decisions. Utah, Colorado, Washington, and Vermont are ranked as the greenest options.

Are seed oils as bad as rumors say?

Some claim seed oils—oils extracted from seeds, such as sunflower or canola—increase inflammation and disease risk, advising consumers reach for saturated fats instead. Saturated fats, typically solid at room temperature, are found in animal products and some vegetable oils, including coconut. When adjusting for lifestyle risk factors, research shows seed oils are, on average, good for one's heart and considered healthy alternatives to saturated fat.

View a map of countries with the safest and most dangerous drinking water

More than a quarter of the world's population lives in water-stressed countries, and a similar number use contaminated drinking water sources, which can lead to widespread disease, according to the World Health Organization. The Environmental Performance Index shows which countries have safe drinking water.

Jet fuel is expensive—which is one reason why it's tough to make an airline profitable

Jet fuel is typically a commercial airline's second-largest expense, second only to labor. Oil prices can be volatile—there have been recent significant increases in jet fuel prices given the 2026 Iran conflict, for instance.

Bill Nye believes a World War II-level mobilization is needed to end climate change

As part of his science advocacy efforts, Nye has argued that existing technologies, including electric vehicles and renewable energy, can already significantly reduce emissions. However, switching to these technologies requires a more expansive awareness of the problem and a greater sociopolitical willingness by policymakers and the general public.

Explore a series of articles on the costs of critical mineral extraction

The acquisition of critical minerals—essential materials for clean energy technologies—has often been accompanied by harm to water supplies, natural ecosystems, and Indigenous lands, raising questions about the overall benefit of these technologies.

The price of gas is a composite made up of several different factors, with the federal gas tax making up less than 20% of what drivers pay at the pump.

Louisiana's 'Cancer Alley' is infamous for having some of the highest industrial pollution, toxic air emissions, and cancer risks in the US.

The deadliest aspect of volcanic eruptions is often not lava, but pyroclastic flows—avalanches of ash, gas, and rock that can move more than half the speed of sound.

An investigation suggests a Scottish island became awash in forever chemicals via seafoam and seaspray—raising questions about what that means for the safety of other coastal areas.

Scientists can determine Earth's past climate conditions by analyzing air trapped in microscopic bubbles within ice cores—columns of compressed snow layers that build up over hundreds of thousands of years.

Sunflowers have long been a symbol of nuclear disarmament because they can extract large amounts of radioactive cesium from soil.

Radioactive elements can introduce software errors because the ionizing radiation they produce can detach electrons from atoms, and computer code relies on the distribution of electrons.

11 people died from firework injuries in the US in 2024.

Animal phobias are likely the most common type of phobias, followed by an extreme fear of heights.

Three Ebola species are responsible for most large outbreaks of the disease, yet the only approved Ebola vaccine is known to work against just one of them.

The United States has had a tumultuous relationship with Cuba since its 1959 revolution, highlighted by a nuclear crisis and a decades-long trade embargo.

The American Society of Civil Engineers' infrastructure report card gave the US a C in 2025, its highest grade since the project launched in 1998.

As of 2025, the most cited papers in science include a review of graphene, methods to improve image recognition, streamlining electron density calculations, and optimizing protein studies.

Indefinite cloning of some endangered species may not sustain their longevity because cloning success rates decrease as genetic mutations accumulate.

The Russia-Ukraine conflict is the largest ground war in Europe since World War II in casualties, forces mobilized, and displacement of civilians.

See a ranking of the best (and worst) Federal Reserve Chairs since 1914 out of the 16 men and women who have held the office since.

In 2026, Finland was named the world's happiest country for the ninth consecutive year based on its wealth, social safety network, and high life expectancy, among other factors.

Iran's Revolutionary Guard Corps is independent of Iran's regular army and is one of the most powerful and influential military-political organizations in the Middle East.

44% of Americans say they pray at least once a day—discover how your state's religiosity stacks up against the rest of the country.

While the first exchange-traded fund (a 'basket' of different assets that can be bought and sold on a stock exchange) in the US only launched in 1993, the global ETF market has grown to more than $10T in the short time since.

Domino's Pizza's 30-minute delivery guarantee was responsible for the chain's 1980s surge, but it was discontinued after the company was found liable for delivery driver accidents.

Most of the observable universe's volume consists of voids and supervoids—enormous regions of space with little to no galaxies, stars, or light.

Gerrymandering works through two techniques: cracking opposing voters across districts to dilute their power, and packing them into a few to waste their votes in lopsided majorities.