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Introduction
The “greenhouse” problem is the discharge to the atmosphere of gases that have the potential to raise the earth’s temperature. If the most optimistic views of climatic scientists prevail, the effect will not greatly exceed past “natural” climate variations. On the other hand, extreme pessimistic views predict that they will cause catastrophic changes. This article does not contribute to this climate debate except to be based on the simple premise that these great emissions are a bad thing, and that it would be of value to formulate realistic measures for their reduction. About 61% of the total calculated greenhouse effect is due to carbon dioxide [CO2] resulting from mankind’s use of carbon-containing fuels. This article puts forward measures that could virtually eliminate these emissions by about 2060 AD, which may be enough to stabilize the existing CO2 content of the atmosphere indefinitely. To the extent that optimism about the climate prevails, the proposals could be adopted to a lesser degree. Changes on a very large scale would be needed, but, on the time scale proposed, these would not be more disruptive than technological and industrial changes that have occurred in the past.
Human advancement
Abundance of energy, that is, when a user can readily obtain as much as is needed at a price that keeps producers in business, has been an integral and universal feature of our industrial civilization. Energy use is essential to prosperity and good living. It uplifts society by eliminating menial and repetitious work and creating leisure. Greenhouse reduction must not be achieved by a reduction of energy use, which would create an impediment to human advancement. What is needed is a changeover from energy involving CO2 emission to other sources. This article shows that it would be possible in this way to greatly reduce the greenhouse problem without harmful curtailment of energy use and without undue disruption of our world political-industrial system that, despite many faults and weaknesses, has been outstandingly beneficial to mankind in the overallRemedial action
To the extent that the greenhouse concern that is now being engendered is judged to be based on rationality, it would be necessary for an anti-CO2 program to work down the scale of Table 1., which is rough because it has been difficult to decide from readily available data how much CO2 emission resulted from each part of the “mixed bag” that each row represents. This scale is intended to progress from the easier and more profitable to the more difficult, and certainly includes some “wishful thinking”.
[1] Hydroelectricity is technologically and economically nearly perfect and CO2 free, but unfortunately the undeveloped amount available is relatively small. In some cases, dams could be rebuilt higher and further downstream, to yield more energy output and storage at higher cost. At the margin, hydroelectricity often involves the exchange of hectares of residential and fertile land for megawatts of grid electricity, and this comparison tends to be emotionally biased.
[2] Nuclear energy is the established non-CO2 emitting energy source that would permit the most effective and immediate remediation of the greenhouse problem. At present, about 18 % of the world’s grid electricity is generated by 450 reactors in 25 different countries, with another 29 reactors in course of construction. France has 59 reactors generating 78% of its electricity and Japan has 56 generating 29%. The safety of nuclear energy has caused concern. Advanced countries typically achieve a life expectancy of 80 years. In energy poor countries, about 50 years is typical. This difference amounts to an immense saving of human life. When a rational attempt is made to decide the relationship between this and energy use, it becomes clear that the share of this due to nuclear energy greatly exceeds the mortality from the single serious accident at Chernobyl to a primitive reactor primitively operated. Nuclear waste has been dealt with without serious difficulty for over 60 years.
[3] “Green” energy; windmills, biomass etc. The attractiveness of these “green” sources increases the further the viewpoint moves from the realities of the electricity industry. Windmills are unsightly, a detriment which could become dominant if the necessary vast “forests” of millions of very large windmills come to be planned, in contrast to the few thousands that have been scattered around so far, heavily subsidized and sited mainly to win votes for politicians. Biomass is discussed below; it is perhaps too valuable to be used for grid electricity. However, there is no need to exclude almost any of these measures. If an anti-greenhouse campaign is judged to be necessary, the right course is to pursue any or all of these technologies as energetically as possible. Whether or not they will be found to be feasible or effective will soon become apparent.
[4] The possible trapping of CO2 is a technology in its infancy and may never mature. However, if the most pessimistic concerns about the greenhouse problem come to be accepted, it is the only way that the world’s immense resources of carbonaceous fuels can retain their great value.
[5] Biomass. The carbon contained in biomass has recently been extracted from the atmosphere so that the energy ranks as net-non-CO2 emitting. Ethanol and methanol, useful fuels for road transport, are already being produced from biomass. Unfortunately their energy content per unit of volume or weight is low and both the quantity and the source of the energy needed to produce them are under question. An attractive prospect is to use grid electricity to hydrogenate the cellulose and lignin biomass to eliminate the oxygen and to combine all the carbon into paraffins such as dodecane, that is, diesel. This excellent liquid fuel would then contain all the energy of the biomass but would also be a “carrier” of the added hydrogen. To achieve much reduction in the very great CO2 emissions from road transport, the scale of biomass development would need to be correspondingly enormous. Very large land areas of genetically engineered monocultures with extensive use of fertilizers and pesticides would probably be necessary,
[6] Hydrogen. As a fuel at the point of use, hydrogen, generated from grid electricity, is excellent, but unfortunately it can only be stored and transported either in large and heavy tanks or as a liquid in tanks that are also large and from which the contents continually evaporate despite elaborate insulation. Much research and development is taking place and should of course be actively continued. Liquid hydrogen seems to be very suitable for air transport, starting with its high energy-to-weight content, though considerable changes in the layout of aircraft would be needed.
Road Transport
This is the most important transport medium for people and materials but it presents a difficult problem in reducing CO2 emissions. The automobile is widely deprecated by the “green” minded but most people who have any choice love their cars – an important case where free choice lacks ”virtue”. In 2007 there are more than 500 million automobiles, about 10 million heavy trucks and about 5 million buses of various kinds in use. This enormous fleet grew from almost nothing, starting mainly from the appearance of the Model T Ford, relegating more energy-virtuous railways to second place and bankruptcy, in only about 40 years. Unfortunately in the present context, road transport is almost totally dependent on liquid carbon based fuels and accounts for about 11 % of the overall greenhouse problem. If it is judged that this contribution must be eliminated, four technologies, trolley systems, batteries, compressed hydrogen and biomass liquids can be considered. Batteries charged from grid electricity, CO2 free as above, can drive road vehicles. Batteries now available use nickel and lithium in sealed enclosures and are thus 100% recyclable, though after a rather short life, typically one year. They store about 200 Watt-hours per kilogram of weight, which can give a range of 200 kilometres of travel in a typical automobile, but they then need a recharge that takes several hours. It seems probable that cars with both large batteries and liquid fuelled engines, a combination already in use, could derive half their total energy from grid electricity. Only a few trolley bus systems remain in business because of the excellence of the modern diesel bus and the low cost of oil, but the changeover could readily be made. It seems likely that liquid fuels will still be needed to provide about half the total energy needed for road transport. The most promising eventual source for these is biomass, as discussed above.
The scale of action needed
An earlier study by the author and others estimated that the world usage of energy in 2060, a date chosen here to give enough time for necessary changes, would be roughly 18.6 teraWatts. To allow, optimistically, for a greater effort to develop “green” energy, that is, windmills, biomass, CO2 trapping etc., the 2.8 teraWatts previously estimated under that heading is now increased by a factor of 2 to 5.6 TW, so that if the maximum anti-greenhouse effort is made on the lines here discussed, the make up could be, roughly:
Grid electricity can be conveniently and economically transmitted over long distances and is universally distributed in the advanced and advancing world. It therefore offers the prospect of being the source or carrier for supplying almost all human energy needs. It can be generated without emission of CO2 as outlined above. Realistically, the total nuclear generating capacity that would be needed in 2060 would be 11 teraWatts. To bring about this change, starting in 2020, a world total of about 68 nuclear power stations of 4 gigaWatts capacity would be manufactured and installed per year. It is difficult to be more precise, particularly since the change over to electrical energy source in the past has almost always resulted in greater energy efficiency. This enormous industrial effort would include the replacement of existing generation stations at the end of their useful lives, which would be needed in any case. If all static uses of energy had been converted to non-CO2 emitting grid electricity, the reduction in total greenhouse effect would be about 42% of the “business as usual” level, leaving perhaps 58 % still uncorrected – a brutal reality!. If all energy for road transport had been converted to non-CO2 emitting sources, a further 10 % reduction of the total could be achieved. The totality of these steps would almost eliminate CO2 emissions resulting from energy use. There do not appear to be any realistic alternatives to these measures. If nuclear stations are assumed to cost 3,000 $[US,2007] per kW, instead of perhaps 2,000 per kW for coal stations, they would represent a shift of about 2 % of the world’s spending and, perhaps, also a cost increase of about 1/2 % in world GFP. In a world with a GFP of which 70% is listed as “services” and where unemployment in advanced countries has usually been around 7%, these changes in 40 years would be relatively minor.
Implementation
The process of moving down Table 1 is the only realistic plan to achieve the elimination or major reduction of CO2 emissions in a reasonably short time with proper regard for human welfare. In the past, major changes in technological industry, such as the elimination of the coal-fired steam railway locomotive and the creation of an immense jet-aircraft transport industry, have been achieved very smoothly. In 5 years of WW2, after a decade of depression, the USA and the British Commonwealth alone built 45 million tons of shipping, in addition to an immensely expanded production of aircraft, tanks, road vehicles and munitions. These developments involved both government and private industrial effort and investment. The changeovers here indicated would be about comparable to these, but they would be spread out over 40 years instead of 5, so that the disruptions involved would be much less and easily accommodated. The major energy industries, coal, oil and natural gas, would be profoundly affected, but the total industrial effort would remain on about the same scale. Economic measures such as emission trading schemes and carbon taxes are often proposed to bring about the intended changes. However, in economic terms, energy is a good that is highly regarded in relation to what has been its usual price, and its price is extensively manipulated, often by governments very dependent on energy revenues. Most kinds of anti-greenhouse measures, if effective, will necessarily reduce demand for fuels, which will greatly reduce their market price, particularly the political component. This reaction, normally beneficial, will tend in this case to defeat economic and taxation measures. But in most advanced countries it would only be necessary for CO2 to be decreed to be noxious, and this would enable the necessary prohibitions for progress down Table 2 to be achieved simply as needed. This approach has been very successfully used in the advanced democratic nations to achieve a big reduction in the emission of smog-causing and health-threatening fumes from hundreds of millions of automobiles and from the burning of bituminous coal. These successive prohibitions, following ample advance notice, would merely be an addition to the mass of natural laws, man-made laws, government regulations, acceptable practices and planning approvals under which industry has developed. These restraints have had no adverse economic effects discernible at least to the layman. An international protocol -- “Kyoto N Real” -- in which the signatory nations would agree to legislate these co-ordinated actions would be needed.
Research and development
Nuclear energy, the most effective remedy to the greenhouse problem if such remedy is judged to be needed, is the product of an immense research and development program of the last century. Clearly, corresponding efforts on a similar scale would be justified in the following areas at least:
[1] Technologies for CO2 trapping as mentioned above.
[2] The production of high-quality liquid fuels by hydrogenation of biomass
[3] The advancement of nuclear breeder technology to full economic viability. This may be necessary if the effectiveness of the nuclear solution leads the demand for uranium to exceed new discoveries earlier rather than later
[4] Spallation-neutron nuclear energy and fusion energy.
[5] Any and all “green” energy sources that show economic or political promise.
Needless to say, mankind’s restless efforts to do better things in the full variety of possible activities should not be restricted by adherence to any single list such as this.
Conclusion
This points to the course of action that may become necessary to manage the greenhouse problem for greatest human net benefit. Worldwide, it is unlikely that mankind will accept restrictions of energy use, and they should not. Serious efforts to curtail the human-caused “greenhouse” gases without restricting energy use are feasible, technically and economically. However, they will only be practicable if broad worldwide scientific and political agreement can be secured. There is a need to work now towards this goal.
(Ed: There are some very interesting responses to this article at:
http://www.energypulse.net/centers/article/article_display.cfm?a_id=1453
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