Explanation: Coal is almost exclusively used to generate electricity and puts out the most CO2 of the three fossil fuels. Related questions What are some examples of carbon sources and carbon sinks? Why are fossil fuels bad? How do fossil fuels form? Why did the plants and animals that make up fossil fuels not rot away? What plants and animals make up fossil fuels? How do fossil fuels differ from other fuels? Overall energy consumption in the United States reached a record high in at quadrillion British thermal units Btu , of which more than 81 quadrillion Btu were from fossil fuels.
Despite the increase, the fossil fuel share of total U. The increase in fossil fuel consumption in was driven by increases in petroleum and natural gas consumption. Coal consumption fell by 4. Natural gas consumption increased in , reaching a new record consumption level of Natural gas consumption has increased in 8 of the past 10 years. Growth in natural gas consumption has largely been driven by increased consumption in the electric power sector.
Certain qualities of fossil fuels are difficult to replicate, such as their energy density and their ability to provide very high heat. To decarbonize processes that rely on these qualities, you need low-carbon fuels that mimic the qualities of fossil fuels.
The energy density of fossil fuels is particularly important in the transportation sector. A vehicle needs to carry its fuel around as it travels, so the weight and volume of that fuel are key. Electric vehicles are a much-touted solution for replacing oil, but they are not perfect for all uses.
Pound for pound, gasoline or diesel fuel contain about 40 times as much energy as a state-of-the-art battery. On the other hand, electric motors are much more efficient than internal combustion engines and electric vehicles are simpler mechanically, with many fewer moving parts.
Industrial processes that need very high heat — such as the production of steel, cement, and glass — pose another challenge. These very high temperatures are hard to achieve without burning a fuel and are thus difficult to power with electricity. For these processes, the world needs zero-carbon fuels that mimic the properties of fossil fuels — energy-dense fuels that can be burned.
A number of options exist, but they each have pros and cons and generally need more work to be commercially and environmentally viable. Biofuels are a possibility, since the carbon released when the biofuel is burned is the same carbon taken up as the plant grew.
However, the processing required to turn plants into usable fuels consumes energy, and this results in CO 2 emissions, meaning that biofuels are not zero-carbon unless the entire process runs on renewable or zero-carbon energy.
Biofuels also compete for arable land with food production and conservation uses, such as for recreation or fish and wildlife, which gets more challenging as biofuel production increases. Fuels made from crop waste or municipal waste can be better, in terms of land use and carbon emissions, but supply of these wastes is limited and the technology needs improvement to be cost-effective. Another pathway is to convert renewable electricity into a combustible fuel.
Hydrogen can be produced by using renewable electricity to split water atoms into their hydrogen and oxygen components.
The hydrogen could then be burned as a zero-carbon fuel, similar to the way natural gas is used today. Electricity, CO 2 , and hydrogen could be also combined to produce liquid fuels to replace diesel and jet fuel. However, when we split water atoms or create liquid fuels from scratch, the laws of thermodynamics are not in our favor.
These processes use electricity to, in effect, run the combustion process backwards, and thus use large amounts of energy. Since these processes would use vast amounts of renewable power, they only make sense in applications where electricity cannot be used directly.
Carbon capture and storage or use is a final possibility for stationary applications like heavy industry. Fossil fuels would still be burned and create CO 2 , but it would be captured instead of released into the atmosphere.
Processes under development envision removing CO 2 from ambient air. In either case, the CO 2 would then be injected deep underground or used in an industrial process.
The most common use for captured CO 2 today is in enhanced oil recovery, where pressurized CO 2 is injected into an oil reservoir to squeeze out more oil. The idea of capturing CO 2 and using it to produce more fossil fuel seems backwards — does that really reduce emissions overall? But studies show that the captured CO 2 stays in the oil reservoir permanently when it is injected in this way.
And if enough CO 2 is injected during oil production, it might make up for the combustion emissions of the produced oil, or even result in overall negative emissions. Carbon capture is today the cheapest way to deal with emissions from heavy industries that require combustion. It has the advantage that it can also capture CO 2 emissions that come from the process itself, rather than from fuel combustion, as occurs in cement production when limestone is heated to produce a component of cement with CO 2 as a by-product.
When considering how carbon capture might contribute to climate change mitigation, we have to remember that fossil fuels are not the ultimate cause of the problem — CO 2 emissions are. Science clearly tells us that we need to remake our energy system and eliminate CO 2 emissions.
However, in addition to the engineering challenges, the nature of climate change makes it politically challenging to deal with as well. These decisions are particularly difficult for politicians, who tend to focus on policies with immediate, local benefits that voters can see. Their perspectives inevitably differ, and the lack of consensus — combined with very real efforts to exert pressure on the policymaking process — is a key reason that climate action is so politically difficult. To try your hand at navigating the policy dilemmas, play our — admittedly simplified!
In the United States and other parts of the wealthy world, current efforts focus on reducing the greenhouse gas emissions from our energy-intensive lives. The need to provide both cleaner energy and more energy for developing countries magnifies the challenge, but a solution that leaves out the developing world is no solution at all.
Plentiful and inexpensive fossil fuels make transitioning away from them more difficult. Events of the past decade have proven that theory wrong. Technology has brought about a boom in oil production; geologists long knew the resources were there, but did not know how to make money producing them. In other words, running out of oil will not save us.
The world will need to transition away from oil and other fossil fuels while they are abundant and inexpensive — not an easy task. To achieve this technically and politically challenging transition, we need to avoid one-dimensional solutions.
My own thoughts about how we need to deal with climate change have certainly evolved over time, as we understand the climate system better and as time passes with emissions still increasing. As an example, I used to be skeptical of the idea of carbon capture, either from industrial processes or directly from the air. The accumulation of CO 2 in the atmosphere is like putting air into a balloon. The cumulative nature of the climate system means that we need more stringent measures the longer that we wait.
In other words: Sooner action is better. Other sectors need more technology, like heavy transport and industry, or will take a long time, like improving our existing stock of buildings.
Those pushing to end fossil fuel production now are missing the point that fossil fuels will still be needed for some time in certain sectors. Eliminating unpopular energy sources or technologies, like nuclear or carbon capture, from the conversation is short-sighted. I fear that magical thinking and purity tests are taking hold in parts of the left end of the American political spectrum, while parts of the political right are guilty of outright denialism around the climate problem.
In the face of such stark polarization, the focus on practical solutions can get lost — and practicality and ingenuity are the renewable resources humanity needs to meet the climate challenge. Correction: An earlier version of a graphic in this piece mistakenly indicated that renewables comprise 0.
It has been corrected to 9. Samantha Gross. June A combo shows the India Gate war memorial on October 17, and after air pollution level started to drop during a day nationwide lockdown to slow the spreading of Coronavirus disease COVID , in New Delhi, India, April 8, Coal, oil, and natural gas are fossil fuels.
Our energy comes from the sun, one way or another. Biomass can be burned directly or processed to create biofuels , like ethanol. How energy density and convenience drove fossil fuel growth.
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