Fossil fuel, any of the classes of biologically-derived, hydrocarbon-containing materials found in the Earths crust which may serve as sources of energy. Fossil fuel is fuel formed through natural processes, such as the anaerobic decomposition of dead organisms that are buried, that contains organic molecules that originated from ancient photosynthesis and which provide energy when burned. Fossil fuels formed over millions of years through burials of photosynthetic organisms, including plants on land and plankton in the sea . Photosynthetic organisms, including plants on land and plankton in the sea . Fossil fuels provide approximately 80% of global energy. Fossil fuels include coal, oil, natural gas, oil shale, bitumen, tar sands, and heavy petroleum. Fossil fuels range from volatile materials with a low carbon-to-hydrogen ratio , to liquids , to non-volatile materials composed of nearly pure carbon, such as anthracite coal. The most significant sources of primary energy are fossil fuels that are based on carbon. Even today, oil, coal, and natural gas supply approximately 80% of our energy needs. When we burn oil, coal, and gas, we are not only meeting our energy needs--we are contributing to the ongoing global warming crisis. To make a dent, the U.S. would have to reduce its energy needs by half, develop renewable sources so they supply at least 80% of our electricity, electrify nearly every mode of transportation, and move fossil fuels from our buildings. Unfortunately, fossil fuels are nonrenewable resources, and waiting millions of years for new deposits of coal, oil, and natural gas to form is not a realistic solution. To address concerns about rising concentrations of greenhouse gases and to diversify their energy mixes, many countries have sought to decrease their reliance on fossil fuels by developing sources of renewable energy such as wind, solar, hydroelectric, tidal, geothermal, and biofuels, while increasing the mechanical efficiency of engines and other technologies that depend on fossil fuels. Technologies such as carbon capture and storage may help to lower greenhouse gas emissions produced from fossil fuels, while nuclear power could become a carbon-free option for generating electricity. CCS has not been proven to be a safe or feasible method for reducing greenhouse gas emissions at commercial power plants, and there are still ongoing environmental and health costs associated with extraction. Carbon capture and storage , in which carbon is separated out of coal and injected underground for long-term storage, can theoretically be used to reduce the greenhouse gas emissions from the coal industry. Carbon capture and storage technologies, along with the management of methane emissions across the fossil fuel energy value chain, can contribute to the implementation of ambitious CO 2 emissions reduction targets, as long as fossil fuels remain a part of the energy system. Given the continued reliance of the world on fossil fuels, it is widely believed that, beyond efforts aimed at replacing them, we must suck the carbon out of the air through technologies like carbon capture, where emissions are moved into underground storage or recycled before reaching the atmosphere. While all sources of energy produce inherently undesirable effects, evidence shows that fossil fuels produce the highest levels of greenhouse gases and are most dangerous for human health. Natural gas is cleaner than coal and oil when it comes to emissions, but it still accounts for one-fifth of global totals, and this does not include so-called fugitive emissions, which can be substantial, which flow away from fossil fuel industries. Increasingly, though, gas is being shipped in liquid form on ships in order to satisfy a large global demand for fuel. As a result, gas has overtaken coal as the leading fuel in the production of U.S. electricity, and the U.S. leads the world in gas production, followed by Russia and Iran. Oil usage has increased moderately over the last four years, as relatively low gasoline prices fueled an increase in car miles traveled and renewed interest in SUVs and light trucks. It is also been a steady shift to fuels that are more energy-dense and easier to use than their replacements. Coal transport requires diesel-powered locomotives, whereas crude oil is usually carried in tankers, which requires burning extra fossil fuels. Coal to liquids--Due to the abundance of coal resources in the U.S., advocates for liquid coal view the fuel as a stable, long-term supply for the transportation industry. The clean coal framework has been promoted more recently as a way of using this abundant energy source without harming the environment. Fossil fuel companies are spending millions of dollars in glossy clean energy advertising campaigns, all while continuing to ramp up production of oil and gas, releasing emissions that are having devastating effects on our planet. While fossil fuels are continuously formed through natural processes, they are classified as a non-renewable resource, as it takes millions of years for them to form, and known reserves are being consumed far faster than new ones are generated. A small fraction of hydrocarbon-based fuels are biofuels, which are derived from atmospheric carbon dioxide, thus they do not add a net amount of CO2 to the atmosphere. Inasmuch as emissions from methane and other short-lived climate pollutants are thought to be greatly underestimated, energy production and usage are probably sources of an even larger proportion of emissions. Once extracted, crude oil is processed at refineries to produce fuel oil, gasoline, liquefied petroleum gas, and other nonfuel products, such as pesticides, fertilizers, pharmaceuticals, and plastics. This declining trend is driven by countries in which supporting measures are in place relative to volumes of extracted fossil fuels, principally oil and natural gas, that have, in many cases, reached their lowest levels since 2011, because of slowing demand for oil as a result of restrictions related to the pandemic, and subsequent production quotas set by OPEC in response. In fact, oil support fell 16 percent, recording the steepest drop in support amounts of any fuel.