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Energy: Can World Meet Demand of Next 50 Years? The demand for energy will increase by at least 50% over current levels during the next 50 years, raising grave concerns over how so much energy can be produced without enormous environmental damage.  By Michael Lindemann Start Date: 8/10/99 Two key world trends are joined in lock-step as we approach the new millennium. One trend is human population growth; the other is human energy consumption. It is now believed by United Nations demographers that, barring unforeseen catastrophic events, there will be approximately 9 billion people on Earth at the close of year 2050. At that time, population will still be growing, though much more slowly than at present. It will probably level out somewhere near 9.5 billion late in the century. Meanwhile, however, all those humans will be consuming energy at least as voraciously as humans do today. With fully 50 percent more people in 2050 than in 1999, energy consumption will be at least 50 percent greater than today; but it could be more than that. Nearly all the increase in human population will occur in today's developing nations, where per capita energy consumption can only be expected to grow rapidly, even as per capita consumption declines in the most developed nations due to greater energy efficiency. Thus, unless there is a massive transfer of state-of-the-art energy-efficient technologies to the developing world (not likely by 2050), it is reasonable to estimate that global per capita energy consumption might be as much as 10 percent greater in 2050 than it is now. How much energy are we talking about? Measured in units of one million tons of oil equivalent (mtoe), total world energy consumption in 1997 is estimated to have been 9,657 mtoe.* In the year 2000, it will be about 10,040 mtoe, the increase being approximately proportional to human population growth. In the year 2050, if per capita consumption stays even, total energy consumption will be in the range of 14,831 mtoe. On the other hand, if per capita consumption is up by 10 percent, total consumption will be about 16,314 mtoe. The question is, where will all that energy come from, and what will be the cost to the planetary environment of producing and consuming it? As of 1997, the latest year for which fairly complete data are available, energy consumed by human society was produced as follows. All figures are in mtoe units.**
Projections of future energy production must take account of the fact that four of today's major energy sources are severely constrained in terms of future growth. These four are oil, hydroelectric, biomass and nuclear. It is widely acknowledged that there is still an enormous amount of oil in the ground. But much of that remaining oil is very expensive to extract -- so much so that major oil companies do not even plan to try unless the price of oil goes up a great deal (double or triple the current level). In time, that will undoubtedly happen. In the meantime, however, the amount of oil that can be profitably extracted and competitively marketed as fuel is definitely limited. (By the time sustained oil prices are above $50 per barrel, oil will be widely regarded as too valuable to simply burn.) Some oil experts believe the steady increase in oil production seen during the last several decades will finally peak in about ten years and then begin to decline. More optimistically, annual oil production could maintain a peak level of around 3400 million tons until the year 2020. But then, by most estimates, it must begin to decline. By 2050, the decline could be precipitous -- 50 percent or more -- and it will continue falling toward zero by century's end. Global hydroelectric power, which depends for the most part on the creation of huge dams on major rivers, has expanded enormously -- nearly 15-fold -- since the year 1950. But today, constrained by the huge capital costs of dam-building, growing concern over damage done to natural river systems and the sheer lack of additional high quality dam sites, the days of major hydroelectric expansion will soon end. In 1997, the total installed capacity of all hydroelectric projects was in the range of 1224 mtoe (725,000 megawatts continuous). A combination of several giant new projects, notably in Asia, and a larger number of small-scale projects throughout the world can optimistically increase total installed capacity to some 1500 mtoe (885,000 megawatts) by the year 2025. From then on, however, growth in capacity will probably be negligible. Hydroelectric, as a mature renewable energy source, has the distinct advantage over oil of being able to maintain nearly its maximum energy production capacity for many decades. But inasmuch as that maximum capacity is strongly constrained, hydroelectric will play a gradually decreasing role in the world's total energy picture from about the year 2020 onward. People in the world's most-developed nations can easily overlook the importance of biomass in the total global energy picture. But in some developing countries, biomass represents the primary source of energy for non-industrial (mainly household) use. In the world as a whole, biomass currently delivers slightly more total energy than nuclear power, about 600 mtoe in 1997. But the future viability of biomass for energy production is severely constrained. Biomass fuel comes from two sources: forest wood and cultivated crops. The vast majority comes from forest wood, and the widespread use of wood for fuel contributes significantly to forest loss in much of the developing world. At present, forest wood is being harvested for fuel at drastically unsustainable rates. Whether through enforced forest protection or its converse, forest destruction, the availability of wood for fuel must rapidly decrease in coming decades. The alternative source of biomass fuel, agriculture, is neither economically nor logistically suited to fill the deficit as fuelwood resources decline. Thus, the biomass share of global energy production will fall steadily during the 21st century. Of all the currently important energy sources, however, nuclear power will see the greatest decline in the decades immediately ahead. Constrained by enormous capital costs, increasingly stifling regulation and strongly negative public sentiment, the nuclear power industry faces extinction within 50 years. It is probable that the total installed capacity estimated for the year 2000 of about 592 mtoe (350,000 megawatts continuous) is the maximum the industry will see. As of year-end 1997, 33 new reactors were under construction worldwide, but this was the lowest level of new construction in 30 years. A number of partially completed new reactors will never see completion, while growing numbers of older reactors will be decommissioned. Only in a few countries, notably China, does there remain a commitment to expand nuclear capacity. Elsewhere, especially in western Europe, the trend is toward rapid elimination of nuclear power. The result seems inevitable. Even with expected growth in parts of Asia, by the year 2020 total nuclear capacity will be down more than 40%. By the year 2050, barring unforeseen developments, nuclear power could be nearly gone.
 Taken together, the combination of oil, hydroelectric, biomass and nuclear power will account in the year 2000 for an estimated 55 percent of total human energy consumption. But in the year 2050, if the foregoing assumptions prove true, these four key energy sources will account for only 22 percent of total human energy needs. Where, then, will our energy come from? Leaving aside (for the moment) the prospect of exotic new means of energy production, we must assume that the majority of human energy needs in the year 2050 will be met by two main resources: coal and natural gas. The good news is that we do have enough proven reserves of these two resources to meet the world's expanding energy needs even well past mid-century. The bad news is that continued and increasing reliance on fossil fuel, especially coal, can only spell disaster for the planetary environment. Particularly worrying is the virtually inevitable acceleration of global climate change brought about by increasing injections of the combustion product carbon dioxide into the atmosphere. There will be at least two other major contributors to the energy picture in 2050, both highly desirable, renewable and environmentally friendly resources: wind and solar photovoltaic power. Both of these energy technologies proved their economic viability during the decade of the 1990s. As we approach the new millennium, installation of new wind generating capacity is increasing globally by the heroic figure of 25 percent per year, and new solar power installation is increasing by nearly 17 percent per year. These remarkable growth rates can be expected to continue well into the next century. But we must also recognize that, at present, the world's total wind and solar power generating capacity represents a barely visible fraction of total power consumption -- just over four hundredths of one percent. In order for wind and solar power to contribute substantially to the world energy picture, they will both have to grow at sustained rates never before seen in the history of power production. Yet, with sufficient economic and environmental incentives, that may be possible. Given the most optimistic projections, by the year 2050, total wind and solar power production could rival the combined energy of nuclear and biomass today -- approximately 1200 mtoe. That figure would account for between 7 and 8 percent of total global energy consumption. After taking stock of wind and solar, we must still account for 70 percent of global energy needs in the year 2050. From a conventional perspective, the world is left no choice but the massive exploitation of coal and natural gas. Both of these energy resources are abundant, economical to access, and easy to use. Indeed, coal is so plentiful and accessible that in some parts of the world, notably China, millions of peasants literally dig it out of the ground themselves, walking it home in hand-carried bags for cooking and heating. But coal and gas differ in one crucial respect. Natural gas is the cleanest-burning of all fossil fuels, while coal is by far the dirtiest. Natural gas is seen by some energy theorists as the ideal "transition fuel" to fill the energy needs of the early 21st century with minimum environmental impact, until exotic new energy technologies can be developed and brought on line. Coal on the other hand is the fuel of desperate last resort from an environmental perspective, but all too likely to be the fuel of choice in much of the developing world simply because it is cheap and available. In a world without alternatives, consumption of coal and natural gas will both increase tremendously. By the year 2050, annual consumption of coal could be double the current level, accounting for at least 27 percent of total energy needs. This figure, in fact, assumes strenuous global efforts to prevent even greater reliance on coal for energy. For that to occur, annual consumption of natural gas will have to triple between the year 2000 and 2050, accounting at mid-century for 44 percent of total energy. It is by no means clear that natural gas production can be economically expanded and sustained at that tremendous rate. Nor is natural gas itself an answer to the worry over global climate change; it is merely less devastating than coal, while still contributing substantially to the rise in atmospheric carbon dioxide. Given all the foregoing, there should be very strong incentives to develop other means of energy production. It is possible that some highly exotic technology will prove viable and dramatically change our energy prospects. Among often-mentioned possibilities are cold fusion, hot fusion and zero-point energy. Each of these has strong proponents, but there is as yet no consensus that any of these theoretical possibilities can result in commercially significant energy production in the coming century.
 Of all the exotic energy options currently under discussion, the one that seems closest to reality is solar-hydrogen production. In this technology, solar energy is used to crack water molecules into hydrogen and oxygen. The process is simple and can be installed along any sunny seashore. The resulting oxygen is vented to the air or directed to other applications as desired. The hydrogen is stored under pressure, then either piped to central power stations or shipped in tanks wherever it is needed. As a fuel, hydrogen is close to ideal. Its combustion energy is extremely high and its only combustion product is water. Hydrogen also has direct application in highly efficient fuel cells. On the downside, because hydrogen molecules are extremely small, pressurized hydrogen is harder to contain than more complex gas molecules such as methane or propane. And even a small leak in a hydrogen fuel system poses a severe threat of explosion. Nonetheless, some hydrogen enthusiasts declare that the entire world energy economy could be based upon solar-hydrogen technology by the end of the 21st century. That may be too optimistic, but solar-hydrogen does have great promise. Unfortunately, so far very little progress has been made toward commercial development.
* Figures are adapted from several publications of the Worldwatch Institute. Their sources include: United Nations Energy Statistics Yearbook (1997); British Petroleum Statistical Review of World Energy (1997); U.S. Dept of Energy International Energy Annual (1996) and Monthly Energy Review (Jan 1998); European Energy Report; Energy Economist; International Atomic Energy Agency; Nuclear News; New York Times; Financial Times. Back
** Despite best efforts, different reports and reporting methods arrive at different figures in virtually all categories, with variation in the range of +/-10%. The numbers used in this report are conservative extrapolations from a combination of sources.Back
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