What are unconventional fossil fuels

Fossil energy sources

Lexicon> Letter F> fossil fuels

Definition: Energy sources that were created during geological times when dead plants and animals were broken down

More general terms: energy carrier

English: fossil energy carriers

Categories: Energy sources, basic terms

Author: Dr. Rüdiger Paschotta

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Original creation: May 1st, 2010; last change: 03/17/2020

URL: https://www.energie-lexikon.info/fossile_energietraeger.html

Fossil energy sources are such energy sources that were created in the long past when dead plants and animals were broken down. These include, in particular, fuels such as coal, oil and natural gas (including shale gas), but also peat; they all store chemical energy. Many of them mainly contain various hydrocarbons. Fossil fuels do not include substances such as biodiesel and biogas, which are made from new plant and animal products (biomass).

Fossil fuels are a blessing and a curse at the same time: They are extremely useful economically, but at the same time cause enormous climate hazards.

Around 80% of global primary energy consumption is currently covered by fossil fuels. The use of fossil fuels, which are abundantly available at least in the short term, has contributed enormously to the development of the prosperity of a substantial part of the world population. On the other hand, it also causes enormous problems, as outlined in the following sections.

Fossil fuels such as crude oil are in principle constantly being formed anew in different places in the earth. However, these processes are extremely slow compared to the speed with which fossil fuels are being mined. That is why fossil energies are not counted among the renewable energies.

Shortage of fossil fuels

While the demand for fossil fuels is still growing significantly, many resources are being increasingly depleted. This is especially true of petroleum; the maximum of global oil production (Peak oil) has in any case been roughly achieved for conventionally produced oil, which can only be temporarily offset by an increasing proportion of “non-conventional” (often very expensive and environmentally harmful) production. If this no longer succeeds, the fall in funding, despite actually increasing demand, is likely to result in severe economic upheavals given the strong dependencies. A few decades later, natural gas is also likely to become scarce globally; funding from many areas, e.g. B. the North Sea, is already losing weight.

As a result of increasing shortages, severe political tensions and even wars are likely to arise in many cases. Even today, a number of wars are at least partially related to the struggle for access to fossil fuels.

However, the problem of shortages could suddenly disappear if the so-called carbon bubble bursts (see below).

Carbon dioxide emissions; the carbon bubble

All fossil fuels contain more or less carbon (mostly coal, least natural gas), so that when they are burned, carbon dioxide (CO2) is released. Since the exhaust gases are almost always released into the atmosphere, the CO increases2-The content of the atmosphere year after year, and this will lead to increasing climate changes.

Avoiding a climate catastrophe requires that a large part of the existing fossil fuels remain unused. In principle, CCS would also be possible, but that should not defuse the problem much.

In principle, the CO2-Problem of fossil fuels, at least for individual large consumers due to CO2- Deposition and storage (CCS technology) are greatly reduced. However, it is still unclear to what extent this will be practicable - probably not for a long time to the extent that would be necessary for a significant reduction in the climate problem.

Everything indicates that an early and extensive phase-out from the use of fossil fuels (see below) will be inevitable - which of course means a huge task.

It must be emphasized that the availability of fossil fuels is limited, but the quantities available are far greater than the quantities required in terms of CO2Emissions may be consumed. This means that the limits for the use of fossil fuels are not set by availability, but by ecological limits.

The market prices for fossil fuels have presumably so far hardly been influenced by the indispensable necessity of severely restricting the consumption of fossil fuels for reasons of climate protection; they are essentially based on the expectation that the energy consumption of mankind will continue to increase and with it the consumption of fossil fuels - although the latter would quite clearly lead to a climate catastrophe. Investments in projects for the extraction of fossil fuels and in systems for their use are correspondingly high today. However, if one day the realization prevails that effective climate protection must be pursued worldwide, and this is actually implemented, the market values ​​of fossil fuels would collapse massively. The markets would then realize that demand would decrease sharply (for example as a result of a comprehensive CO2Emissions trading system with sharply rising allowance prices). Initially, moderately falling prices would quickly trigger a downward spiral, as all providers of fossil fuels (e.g. crude oil) wanted to quickly sell what soon could no longer be sold. This would be the bursting of the so-called carbon bubble, which is explained in more detail in the corresponding lexicon article.

Other environmental impacts from use

When fossil fuels are burned, toxic air pollutants such as carbon monoxide (CO) and nitrogen oxides (NOx), unburned hydrocarbons (HC) and particulate emissions e.g. B. from soot (→ fine dust). These pollutants cause massive health problems in many places. However, such emissions are heavily dependent on the type of fuel and its use, and can be greatly reduced by using suitable exhaust gas cleaning systems.

Environmental pollution in mining and transport

The extraction and transport of fossil fuels is also sometimes very polluting:

  • Accidents in oil production (especially on oil platforms in water) and tanker accidents repeatedly lead to severe destruction of ecosystems. Due to the exhaustion of conventional oil deposits, unconventional extraction methods (e.g. for oil sands), which are even more polluting, are increasingly being used.
  • During the production and transport of natural gas, leaks can lead to considerable amounts of methane entering the atmosphere, which are much more harmful to the climate than the carbon dioxide that is otherwise produced during combustion. In the case of natural gas production, too, unconventional extraction methods, e.g. B. for shale gas usually bring higher environmental pollution.
  • When lignite is extracted in open-cast mining, entire landscapes are destroyed (and not always restored after extraction). The lignite and hard coal production creates z. T. considerable perpetual costs.

People are also often directly harmed, e.g. B. in accidents in coal mines or the collapse of coal pits.

Reducing dependence on fossil fuels

The dependence on fossil fuels can be reduced in different ways:

Phasing out the use of fossil fuels

The exit from fossil fuels will be more difficult than the nuclear phase-out. But this is not less necessary!

Over the next few decades, it will be necessary to largely phase out the use of fossil fuels worldwide in order to avoid a climate catastrophe. The majority of climate scientists have come to the conclusion that the rise in global temperature should not exceed around 2 ° C in order to avoid unsustainable damage. In order to achieve this 2-degree target, however (as of 2012) only around 600 gigatons of carbon dioxide should be released into the atmosphere. If global emissions were to be frozen at the 2010 level (31.8 gigatons), emissions would have to cease completely around 2029, which is of course completely impossible. At the moment, emissions are even rising sharply. The longer it takes for annual emissions to fall, the faster the emissions must then fall in order to avert a climate catastrophe. In any case, the emissions and thus the consumption of fossil fuels must be much lower in the medium and long term than they are today. In any case, there is little to be said for the hope that the phase-out from the use of fossil fuels could be avoided, because either climate science is issuing completely unjustified warnings or means are being found in the future, the situation despite increasing CO2-Concentration of the atmosphere to control.

Incidentally, the reductions in consumption that the increasing scarcity of energy sources enforce will by no means be sufficient to avert a climate catastrophe. In some cases, a shortage even leads to recourse to other energy sources, which lead to even higher emissions - for example, non-conventional crude oil from oil shale as a replacement for conventionally extracted crude oil.

Despite these circumstances, which can hardly be doubted, the goal of phasing out the use of fossil fuels - in particular phasing out coal - has so far hardly been formulated politically.

The most effective approach to accomplish this exit would be a cap-and-trade system installed worldwide. Ideally, this would not work at the level of emissions trading, but instead start with the amounts of carbon that are brought onto the market in the form of fossil fuels. This is because recording is much easier at this level. However, efforts to trade emissions are already further developed, which speaks in favor of using this path, especially since there is very little time left for developing and introducing new instruments.

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See also: Energy, energy carriers, chemical energy, hydrocarbons, fuel, crude oil, natural gas, coal, emissions and immissions, carbon dioxide, climate hazards, perpetual costs, CO2-Separation and storage, coal exit, incineration
as well as other articles in the categories of energy sources, basic terms

Understand everything?


Question: Which of the following energy sources are considered to be fossil fuels?

Correct answers: (a), (b), (c), (e)


Question: Is CO2 from the combustion of fossil fuels more problematic than CO2 of biofuels, humans and animals?

Correct answer: (b)
To (c): This applies e.g. B. for biofuels also, even to a greater extent. (b) is the crucial point: What CO2 gives off, was previously bound by plants. Burning fossil fuels, on the other hand, brings carbon into the atmosphere that would otherwise have remained underground.


See also our energy quiz!