World energy resources
There is uncertainty in the total amount of reserves, but also in how much of these can be recovered gainfully, for technological, economic and political reasons, such as the accessibility of fossil deposits, the levels of sulfur and other pollutants in the oil and the coal, transportation costs, and societal instability in producing regions.
This was the fuel that launched the industrial revolution and continued to grow in use; China, which already has many of the world's most polluted cities,[2] was in 2007 building about two coal-fired power plants every week.
Improvements in technology and wide exploration led to a major increase in recoverable natural gas reserves as shale fracking methods were developed.
At present usage rates, natural gas could supply most of the world's energy needs for between 100 and 250 years, depending on increase in consumption over time.
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).
[10] A 2005 French Economics, Industry and Finance Ministry report suggested a worst-case scenario that could occur as early as 2013.
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, and 73.697 in 2008.
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 1 January 2009.
[13] Political considerations over the security of supplies, environmental concerns related to global warming and sustainability are expected to move the world's energy consumption away from fossil fuels.
The concept of peak oil shows that about half of the available petroleum resources have been produced, and predicts a decrease of production.
A government moving away from fossil fuels would most likely create economic pressure through carbon emissions and green taxation.
IPCC estimated currently proved economically recoverable uranium deposits for once-through fuel cycles reactors to be only 2 ZJ.
[18] Resources and technology do not constrain the capacity of nuclear power to contribute to meeting the energy demand for the 21st century.
It generates large quantities of heat by fusing the nuclei of hydrogen or helium isotopes, which may be derived from seawater.
[24][25][26] Geothermal and biomass are the only two renewable energy sources that require careful management to avoid local depletion.
[27] Estimates of exploitable worldwide geothermal energy resources vary considerably, depending on assumed investments in technology and exploration and guesses about geological formations.
[29] A 2006 report by the MIT that took into account the use of Enhanced Geothermal Systems (EGS) concluded that it would be affordable to generate 100 GWe (gigawatts of electricity) or more by 2050, just in the United States, for a maximum investment of 1 billion US dollars in research and development over 15 years.
Globally, solar generation is the fastest growing source of energy, seeing an annual average growth of 35% over the past few years.
China, Europe, India, Japan, and the United States are the major growing investors in solar energy.
