What Should We Do Now?
Yoshiaki FUJII and Sayaka ISHIMOTO
Rock Mechanics Laboratory, Hokkaido Univ., JAPAN
ABSTRACT
The next glacial period will occur in 50,000 years. Air temperatures will drop by 10 degrees centigrade, and sea level will become as low as the continental shelves. Northern Europe and Canada will be covered by ice sheets. If humans have not evolved significantly and are not very different from humans today, many people will need to move to warmer regions. Some nations, if they are constituted more or less as they are presently, will undergo devastating changes. The author finds it impossible to imagine the nature of human life after the next glacial period. We will therefore consider how to maintain human society as comfortably as it is at present only until the peak of the next glacial period.
Potential problems for human society include population increase, water shortage, food crises, exhaustion of resources, global warming, economic crises, comet impacts, massive earthquakes, catastrophic eruptions, HIV, malaria, avian (bird) flu, Methicillin-resistant Staphylococcus aureus (MRSA), poverty, religious wars, nuclear wars, etc. Spatial and temporal scales, as well as the characteristics of these problems, differ from one another and influence each other. Let us select the first 5 problems and consider their relationships.
Water shortage will accelerate the food crises and decelerate population increase. Food crises will decelerate population increase. Exhaustion of resources will accelerate food crises, because agricultural machines, chemicals, fertilizers, irrigation, transportation, etc. strongly depend on energy resources. Global warming will accelerate water shortages and will decelerate food crises but will vanish when fossil energy resources are exhausted. Lastly, population increase will accelerate all 4 problems. It is therefore very easy to say that population increase is the source of the 5 problems even without computer simulations.
Population in the developed countries is almost constant, but it in the developing countries is still increasing significantly. Clearly, population in the developing countries should be stabilized. The ethical way to approach this problem would be to furnish financial aid to developing countries to promotethe education of women. These measures will encourage women to work and will finally lead to a decreased birth rate and to population stabilization. Education about birth control and free distribution of contraceptive devices should both be carried out simultaneously in the developing countries. This approach also leads to reducedlevels of HIV infection. A two-child policy will be very effective if it is adopted by the United Nations.
Some unconventionalapproaches also exist. One approach would be to decrease human height instead of stabilizing the population. This result can be achieved without causing any technical problems by using the same approach that produced domestic animal breeds (e.g.,the Chihuahua, ponies). For example, society could prohibit people taller than 160 cm from having children. After 30 years, the limit could be changed to 150 cm. Encouraging homosexuality is another approach. Prohibitions of homosexuality appear rather problematic in the context of the current discussion. Humans will also be able to move to other planets in 10,000 years.
Let us now consider the other 4 problems cited above. Water shortagesare already serious and will grow even more serious as populations increase and as global warming intensifies. Populations should be stabilized as soon as possible. The amount of food in the world is not insufficient. Food crises are a political problem and will not becomemore severeafter populations are stabilized. Energy resources will be adequate for the next 74 years if conventional sources are used by stabilized populations. Use of such new fossil energy sources as oil sands, natural gas from shale, methane hydrate, coal bed methane, etc. will postpone the exhaustion of energy resources for several more decades. Thorium and sea uranium can be used by world energy consumers beginning 100 years from now. The former source will serve to supply all primary energy for 140 years, and the latter source will serve for one million years (estimates based on 2008 data). Sea uranium can be exploited for 100 million years if fast breeder reactors are used. Mineral resources have never been exhausted and will not be exhausted easily in the future for the following reasons: (1) mining companies prospect and explore only for several decades, (2) resources will increase and recycling will be carried out willingly as prices increase and (3) substitutes will be developed.
Some people believe that global warming is the most serious threat tothe future of humanity. These people advocate attempts to stop global warming by reducing anthropogenic CO2 emission. According to the Fourth Assessment Report of the IPCC, globalmean surface temperature would rise by 2.3 degrees centigrade from 2000 to 2050 if present levels of CO2emissions continue. The report predicts that reducing CO2 emissions by 50% would moderate global warming by 0.6 degrees centigrade. The accompanying economic loss would exceed 5.5%. The world GDP loss via the Lehman shock effect was 1.5%. The author does not believe that the world can sustain four Lehman shocks in order to achieve a global warming mitigation of just 0.6 degrees centigrade.
The author's opinion on this issue differs from that expressed by IPCC. Arguably, most attempts to reduce CO2 actually increase CO2 emissions because the environmental businessesinvolved in these attempts apparently increase GDP. CO2 emissions apparently increase with GDP increases. In fact, they exhibit a positive correlation. Increased CO2 emissions mean increased fossil energy consumption. This logic is not fully proven, but some suggestive evidence is available, e.g.,charging of electric vehiclesby using coal- generated electricity, oxygen combustion for carbon dioxide capture and storage (CCS), and bio-ethanol. The best approach would attempt not to increase CO2. This goal can be attained by population stabilization, by quitting unreasonable attempts to reduce CO2 and by improving the efficiency of coal-fueled power plants in the US, India and China to the Japanese level (more than 40%). One of the authors has also started to investigate the possibility of injecting fine limestone powder into the stratosphere to mitigate global warming. This measure represents a possible alternative to reducing CO2 emissions.
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