Peak coal is the point in time at which the maximum global coal production rate is reached, after which, according to the theory, the rate of production will enter to a terminal decline. Coal is a fossil fuel formed from plant matter over the course of millions of years. It is a finite resource and thus considered to be a non-renewable energy source.
There are two different peaks: one measured by mass (i.e. metric tons) and another by energy output (i.e. petajoules). The energy output per mass has dropped significantly since 2000, so the energetic peak will come much sooner than the mass peak.
The estimates for global peak coal extraction vary wildly. Many coal associations suggest the peak could occur in 200 years or more, while scholarly estimates predict the peak to occur as soon as the immediate future. Research in 2009 by the University of Newcastle in Australia concluded that global coal extraction could peak sometime between the present and 2048. Global coal reserve data is generally of poor quality and is often biased towards the high side. Collective projections generally predict that global peak coal extraction may occur sometime around 2025 at 30 percent above current extraction.
Hubbert's theory 
The contemporary concept of peak coal follows from M. King Hubbert's Hubbert peak theory, which is most commonly associated with Peak oil. Hubbert's analysis showed how each oil well, region, and nation has a depletion curve. However, this question was originally raised by William Stanley Jevons in his book The Coal Question back in 1865.
Hubbert noted that United States coal extraction grew exponentially at a steady 6.6% per year from 1850 to 1910. Then the growth leveled off. He concluded that no finite resource could sustain exponential growth. At some point, the rate of extraction will have to peak and then decline until the resource is exhausted. He theorized that extraction rate plotted versus time would show a bell-shaped curve, declining as rapidly as it had risen. Hubbert used his observation of the US coal extraction to predict the behavior of peak oil.
The Hubbert Linearization using yearly production rates has minor weaknesses for peak coal calculation, as the signal-to-noise ratio is inferior with coal mining data compared to oil extraction. As a consequence, Rutledge uses cumulative production for linearization. By this method the estimated ultimate recovery results in a stable fit for active coal regions. The ultimate production for world coal is estimated to be 680 Gt, of which 309 Gt have already been produced.
Peak coal for individual nations 
As of 2005, the top coal-extracting countries were China (44% of world extraction), United States (20%), India (8%), and Australia (7%). Each of these four largest coal-extracting countries are experiencing significant increases in coal extraction.
People's Republic of China 
The People's Republic of China is the world’s largest coal extractor and has the third largest reserves after Russia and the United States. The Energy Watch Group predicts that the Chinese extraction will peak around 2015. The EWG also predicts that the recent steep rise in extraction will be followed by a steep decline after 2020. Another study puts the peak at 2027. The US Energy Information Administration projects that China coal extraction will continue to rise until 2030.
United States 
Total mass extracted 
Coal extraction peaked in the early 1900s, then declined sharply during the depression years of the 1930s. Coal extraction peaked again in the 1940s, then declined during the 1950s. Then coal extraction revived, and has been on a nearly continual increasing trend since 1962, exceeding the previous peaks. Extraction in 2006 was a record 1.16 billion short tons. High-grade anthracite coal peaked in 1914; and declined from 44 million tons in 1950 to 1.6 million tons in 2007. Bituminous coal extraction has also been declining since 1990. The slack has been taken up by large increases in subbituminous coal extraction. Comprehensive analysis of historical trends in US coal extraction, reserve estimates along with a possible future outlook has been recently published scientific journals on coal geology .
Energetic peak 
Coal extraction in the United States, currently the world's second largest extractor, has undergone multiple peaks and declines, but total coal energy output peak was reached in 1998 at 598 million tons of oil equivalents (Mtoe); by 2005 this had fallen to 576 Mtoe, or about 4% lower.
- Expected total peak extraction: Sometime after 2050
Australia has substantial coal resources, mostly brown coal. It is responsible for almost 40% of global coal exports worldwide, and much of its current electricity is generated from coal-fired power stations. There are tentative plans to very slowly phase out coal electricity generation in favor of gas, although these plans are still a topic of much debate in Australian politics.
Long-term plans for coal in Australia include large-scale export of brown coal to large developing nations such as China and India. Other groups such as the Australian Greens, suggest that coal be left in the ground to avoid its potential combustion either in Australia or in importer nations.
Research in 2009 by the University of Newcastle in Australia concluded that Australian coal extraction could peak sometime after 2050. While the Australian Coal Association (ACA) optimistically estimates that Australia's identified black coal resources could last more than 200 years based on rate of extraction in 2007. This does not account for brown coal stocks.
New South Wales 
According to calculations conducted for the Hunter Community Environment Centre in Newcastle, the Australian state of New South Wales 10,600 million tonnes of coal reserves would be exhausted by 2042, based on current industry growth and extraction rates of about 3.2 per cent a year.
United Kingdom 
Coal output peaked in 1913 in Britain at 287m tons and now accounts for less than one percent of world coal extraction. 2007 extraction was around 15m tons.
Germany hit peak hard coal extraction in 1958 at 150 million tons. In 2005 hard coal extraction was around 25 million tons. Total coal extraction peaked in 1985 at 578 million short tons, declined sharply in the early 1990s following German reunification, and has been nearly steady since 1999. Total coal extraction in 2005 was 229 million short tons, four percent of total world extraction.
World peak coal 
- 2150 M. King Hubbert
M. King Hubbert's 1956 projections from the world extraction curve placed world peak coal at 2150.
- 2025 Energy Watch Group
Coal: Resources and Future Production, published on 5 April 2007 by the Energy Watch Group (EWG) found that global coal extraction could peak in as few as 15 years. Reporting on this, Richard Heinberg also notes that the date of peak annual energetic extraction from coal will likely come earlier than the date of peak in quantity of coal (tons per year) extracted as the most energy-dense types of coal have been mined most extensively.
- Institute for Energy
The Future of Coal by B. Kavalov and S. D. Peteves of the Institute for Energy (IFE), prepared for European Commission Joint Research Centre, reached conclusions similar to those of Energy Watch Group, and stated that "coal might not be so abundant, widely available and reliable as an energy source in the future". Kavalov and Peteves did not attempt to forecast a peak in extraction.
- US Energy Information Administration projects world coal consumption to increase through 2035.
See also 
- "Research forecasts world coal production could peak as soon as 2010". The University of Newcastle, Australia. 28 October 2009.
- "Coal: Resources And Future Production" (PDF). Energy Watch Group. 10 July 2007. p. 8. Retrieved 20 August 2010.
- Coal: Resources and Future Production. Energy Watch group. 28 March 2007, revised 10 July 2007.
- Uranium Resources and Nuclear Energy. Energy Watch Group. December 2006.
- M. King Hubbert (June 1956). "Nuclear Energy and the Fossil Fuels 'Drilling and Production Practice'" (PDF). API. p. 36. Retrieved 18 April 2008.
- M. King Hubbert (June 1956). "Nuclear Energy and the Fossil Fuels 'Drilling and Production Practice'" (PDF). API. p. 8. Retrieved 18 April 2008.
- David Rutledge (Januar 2011), "Estimating long-term world coal production with logit and probit transforms" (in German), International Journal of Coal Geology (Elsevier) 85 (1): pp. 23-33, doi:10.1016/j.coal.2010.10.012, http://www.sciencedirect.com/science/article/pii/S0166516210002144. Retrieved 2012-11-10
- "World coal production, 1980-2005" (XLS). US Energy Information Agency.
- "International Energy Outlook 2008" (PDF). US Enegy Information Administration. p. 52. Retrieved 24 January 2009.
- "Coal: Resources and Future Production". Energy Watch Group. 2007.
- Heinberg, Richard (21 May 2007). "Peak coal: sooner than you think". EnergyBulletin.net.
- US Energy Information Agency: Coal production, selected years, 1949-2007
- Höök, Mikael; Aleklett, Kjell (2009). "Historical trends in American coal production and a possible future outlook". International Journal of Coal Geology.
- Gregson Vaux (27 May 2004). "The Peak in U.S. Coal Production". From the Wilderness. Retrieved 30 June 2008.
- "Brown promises allure of gold in new coal economy". The 7:30 Report. 15 May 2012.
- "Reserves to dry up as clean coal becomes viable". The Sydney Morning Herald. 10 April 2007.
- David Strahan (5 March 2008). "Lump sums". London: The Guardian. Retrieved 9 June 2008.
- M. King Hubbert (June 1956). "Nuclear Energy and the Fossil Fuels 'Drilling and Production Practice'" (PDF). API. p. 21. Retrieved 18 April 2008.
- Richard Heinberg (21 May 2007). "Peak coal: sooner than you think". Energy Bulletin. Archived from the original on 22 May 2008. Retrieved 6 June 2008.
- Richard Heinberg (March 2007). "burn the furniture". Richard Heinberg. Retrieved 6 June 2008.
- US Energy Information Administration. "International Energy Outlook 2011". Retrieved 29 January 2013.
Further reading 
- "Statistical Review of World Energy 2008". Beyond Petroleum. Retrieved 16 June 2008.
- "Coal Data, Reports, Analysis". US Energy Information Administration. Retrieved 16 June 2008.
- "McCloskey's Coal Report". McCloskey Coal. Retrieved 16 June 2008.
- "Energy Export Databrowser". Mazama Science. Retrieved 25 March 2010.
- "World: Mining - Coal Mining - Industry Overview". MBendi. Retrieved 16 June 2008.
- Michael Orme (15 January 2008). "Are we heading for peak coal?". Money Week. Retrieved 16 June 2008.
- David Strahan (19 January 2008). "Coal: Bleak outlook for the black stuff". New Scientist (2639). Retrieved 25 June 2008.
- Graham Stewart (13 September 2008). "Remember when coal was going to run out?". London: Sunday Times.
- Les Jones (2 January 2009). "Peak coal". A Bouquet of Weeds.