The Hubbert peak theory is most known for being applied to the peak in oil production. However, it can also be applied to other natural resources such as coal, gas and even water.
The concept of finding the production peak of a natural resource follows from M. King Hubbert's peak oil theory. Hubbert considered oil, gas and coal as natural resources, each of which would peak in production and eventually reach depletion for an area, a country and the world.
Peak coal is reached when the maximum rate of coal production has been reached, after which the rate of coal production declines. Coal is a fossil fuel formed from plant remains over a time period of millions of years. There is only a limited amount of coal available, thus it is considered to be a non-renewable energy source.
William Stanley Jevons, an economist, was the first person who wrote about peak coal in his book The Coal Question back in 1865. The book described Britain's reliance on coal.
Given that coal was a limited, non-renewable energy resource, Jevons raised the question of sustainability. "Are we wise," he asked rhetorically, "in allowing the commerce of this country to rise beyond the point at which we can long maintain it?"
In his book Jevons concluded that the British global dominance was transitory, given the limited availability of its primary energy resource, coal. Based on that conclusion Jevons described multiple issues such as overpopulation, growth limits, overshoot, energy return on energy input, post-global re-localization, energy alternatives, and coal peaking.
In chapter one of The Coal Question Jevons describes the importance of coal "Coal in truth stands not beside but entirely above all other commodities. It is the material energy of the country — the universal aid — the factor in everything we do. With coal almost any feat is possible or easy; without it we are thrown back into the laborious poverty of early times. With such facts familiarly before us, it can be no matter of surprise that year by year we make larger draughts upon a material of such myriad qualities — of such miraculous powers." Jevons further explains that coal is a crucial resource for the British prosperity and global dominance.
The predictions for the peak in global coal production vary wildly. Many coal experts claim it will take at least 200 years before peak coal occurs, but there are also experts who predict the peak will occur as early as in 2011. The University of Newcastle in Australia reported, in 2009, that the global coal peak could occur somewhere between 2010 and 2050.
Peak gas is reached when the maximum rate of gas production has been reached, after which the rate of gas production declines. Natural gas is a fossil fuel formed from plant remains over a time period of millions of years. There is only a limited amount of gas available, thus it is considered to be a non-renewable energy source.
Nearly 25% of the global energy consumption comes from natural gas. In the last 30 years the gas consumption has almost doubled. Energy experts predict that in the next 20 years the demand of natural gas will increase further. It is expected that in the future the natural gas will come mostly from developing countries.
David L. Goodstein, an American physicist and educator, claims the global peak in natural gas discoveries occurred in 1960. Harry J. Longwell, the Vice President of Exxon Mobile, claims the global peak in natural gas discoveries occurred in 1970. In 1980 the rate of gas discoveries has fallen below the gas consumption rate. The gap between gas discoveries and consumption has only been increased. Declining gas discovery rates are a forecast for gas production decline rates because gas production can only follow gas discoveries.
Global natural gas discoveries, with 1970 as peak
In October 2009 the chief executive of BP, Anthony Hayward, claimed that global gas reserves have risen up to nearly to 1.3 trillion barrels of oil equivalent. That's enough gas for the next six decades, assuming the gas consumption will not increase, and gas reserves are trending upward. However energy experts such as the former BP chief petroleum engineer, Jeremy Gilbert, claim a similar situation happened with oil reserves, like gas reserves the oil reserves increased despite the actual decline of global oil discoveries and increases in consumption. He suggests the increase of reserves "results largely from distortions created by the..reporting rules of the US Securities and Exchange Commission" and that "even this illusory growth is unlikely to last."
The purpose of Hubbert's peak theory is to predict when the peak of oil and other non-renewable resources occurs. But in the last few years, researchers have begun to apply Hubbert's theory on renewable resources to research whether consumption of some renewable resources follows Hubbert’s theory.
The term peak water is a new concept which helps to understand the growing problems on the quality, availability, and use of freshwater resources. The term peak water has become, like peak oil, a popular topic. Peak water has reached so much attention that The New York Times picked the term "peak water" as one of their 33 "Words of the Year" for 2010.
In 2010 two researchers named Meena Palaniappan and Peter Gleick wrote an article in the Proceedings of the National Academy of Science about peak water. In the article they defined peak non-renewable, peak renewable, and peak ecological water. Most of the planet's surface contains water, but sustainably water is becoming scarce, the water in lakes and underground behave like a finite resource which eventually reach depletion.
Global Water Shortage
There are concerns peak water is being reached in many regions around the world. Some regions are suffering from peak renewable water, where entire renewable flows are being consumed by humans, peak non-renewable water, where groundwater aquifers are being pumped faster than nature can recharge them, and peak ecological water, where environmental and ecological rules are being ignored for economical benefits provided by water use.
Potential peak water curve for production of groundwater from an aquifer
Researchers predict when present trends continue, a global water shortage will occur, nearly 2 billion people will be living with absolute water scarcity by 2025, and 2/3 of the total world population could be affected by the water shortage. Peak water is not about fresh water depletion, but about reaching economic, physical, and environmental limits on meeting human demands for water and the subsequent decline of water availability and use.