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Fossil fuel

Main article: Fossil fuel

Remaining reserves of fossil fuel are estimated as: Assessment Team |

Fuel	Energy reserves in ZJ
Coal	290.0
Oil	18.4
Gas	15.7

Significant uncertainty exists for these numbers. The estimation of the remaining fossil fuels on the planet depends on a detailed understanding of the Earth crust. This understanding is still less than perfect. While modern drilling technology makes it possible to drill wells in up to 3 km of water to verify the exact composition of the geology, one half of the ocean is deeper than 3 km, leaving about a third of the planet beyond the reach of detailed analysis. The Energy Watch Group reports suggest that supplying the demand for oil may be insufficient,^[36] and that uranium resources would be exhausted within 70 years.^[37] However, these views are greatly at variance with those of most industry observers.

Coal

Main article: World coal reserves

Coal is the most abundant fossil fuel. This was the fuel that launched the industrial revolution and has continued to grow in use; China, which already has many of the world's most polluted cities,^[38] was in 2007 building about two coal fired power plants every week.^[39][40] Coal is the fastest growing fossil fuel and its large reserves would make it a popular candidate to meet the energy demand of the global community, short of global warming concerns and other pollutants.^[41] According to the International Energy Agency the proven reserves of coal are around 909 billion tonnes, which could sustain the current production rate for 155 years,^[42] although at a 5% growth per annum this would be reduced to 45 years, or until 2051. With the Fischer-Tropsch process it is possible to make liquid fuels such as diesel and jet fuel from coal. Citing concern for global warming, the Stop Coal campaign calls for a moratorium on the construction of any new coal plants and on the phase out of all existing plants.^[43] In the United States, 49% of electricity generation comes from burning coal.^[44]

Oil

See also: Oil reserves and Peak oil

It is estimated that there may be 57 ZJ of oil reserves on Earth (although estimates vary from a low of 8 ZJ,^[1] consisting of currently proven and recoverable reserves, to a maximum of 110 ZJ^{[citation needed]}) consisting of available, but not necessarily recoverable reserves, and including optimistic estimates for unconventional sources such as tar sands and oil shale. Current consensus among the 18 recognized estimates of supply profiles is that the peak of extraction will occur in 2020 at the rate of 93-million barrels per day (mbd). Current oil consumption is at the rate of 0.18 ZJ per year (31.1 billion barrels) or 85-mbd.

There is growing concern that peak oil production may be reached in the near future, resulting in severe oil price increases.^[45] A 2005 French Economics, Industry and Finance Ministry report suggested a worst-case scenario that could occur as early as 2013.^[46] There are also theories that peak of the global oil production may occur in as little as 2–3 years. The ASPO predicts peak year to be in 2010. Some other theories present the view that it has already taken place in 2005. World crude oil production (including lease condensates) according to US EIA data decreased from a peak of 73.720 mbd in 2005 to 73.437 in 2006, 72.981 in 2007, 73.697 in 2008.^[47] According to peak oil theory, increasing production will lead to a more rapid collapse of production in the future, while decreasing production will lead to a slower decrease, as the bell-shaped curve will be spread out over more years.

In a stated goal of increasing oil prices to $75/barrel, which had fallen from a high of $147 to a low of $40, OPEC announced decreasing production by 2.2 mbd beginning January 1, 2009.^[48]

Sustainability

Political considerations over the security of supplies, environmental concerns related to global warming and sustainability will move the world's energy consumption away from fossil fuels. The concept of peak oil shows that we have used about half of the available petroleum resources, and predicts a decrease of production.

A government led move away from fossil fuels would most likely create economic pressure through carbon emissions and green taxation. Some countries are taking action as a result of the Kyoto Protocol, and further steps in this direction are proposed. For example, the European Commission has proposed that the energy policy of the European Union should set a binding target of increasing the level of renewable energy in the EU's overall mix from less than 7% today to 20% by 2020.^[49]

The antithesis of sustainability is a disregard for limits, commonly referred to as the Easter Island Effect, which is the concept of being unable to develop sustainability, resulting in the depletion of natural resources.