Supplemental section of the file (for printing purposes, starts at p. 102)
Download 1.03 Mb.
|
- Navigate this page:
- Small Asteroids
- Ozone depletion causes complete extinction
Asteroid impact – EconomyNEO strike collapses global economyDore ‘7 (Mohammed, Climate Change Laboratory, Department of Economics, Brock University, Ch. 29: The Economic Consequences of Disasters due to Asteroid and Comet Impacts, Small and Large, in Comet/Asteroid Impacts and Human Society: An Interdisciplinary Approach, SpringLink) Suppose the capital market disruption was accompanied by a more serious financial crisis, perhaps because of the destruction of a government along with its Central Bank. Following such an impact a government might be perceived to be financing recovery by issuing more currency. A loss of some minor currency would not be a problem. Even the loss of an internationally traded currency such as the Canadian dollar would not be a problem, as those affected would merely shift to one of the major currencies such as the US dollar, which is now the reserve currency of the world. But if the magnitude of the NEO impact were large enough to destroy confidence in a major world currency, such as the Japanese Yen, the euro or the US dollar, then its consequences could be serious on a global level. Loss of confidence in a major currency can be rapid. The worst decline in a major currency occurred in Germany between January 1921 and December 1923, as shown in Table 29.4. It shows a rapid decline in the external value of the currency, as domestic prices rose in response to the German government printing more and more currency to meet its reparation obligations. This occurred after it lost a large part of its productive capacity after WW I along with the destruction of the state apparatus and its ability to levy taxes. With regard to the social cost of this hyperinflation, it is worth noting that the real quantity of money (after adjusting for inflation) declined by 92 percent, indicating a virtual collapse of monetary exchange and a return to barter (Keynes 1923). After this loss of confidence in the German Mark, the government introduced a new currency, called the Rentenmark, and declared that one unit of the new currency would be equal to 1 trillion (i.e. 1012) old marks! Hungary, Poland and Austria had similar experiences, although the German case was the most spectacular. Thus history shows that a fiat currency can collapse, and collapse most dismally, under the right conditions. A dramatic decline in the external value of the US dollar could occur even if there were not a catastrophic NEO, but some “large” event that shakes the confidence of the international community, especially as the US has now become a debtor country and does not have enough reserves to cover its external debt, as the Table 29.5 shows. The comparison of Reserves of Foreign Exchange and Gold with external debt should be carried out with care. The external debt can be held in government bonds, or it can be held in the form of equity in real investments in corporations in the form of plant, machinery and equipment. The external debt results in an annual flow of dividends and interest payments out of the indebted countries. It is this flow that can be jeopardized when the level of reserves and holdings of foreign currencies is inadequate to meet the flow. A depreciation of the currency (in terms of its external value) can follow. If a NEO impact that interferes with this annual flow could have a serious effect on that particular currency, it could be “dumped” in the market, leading to its precipitous decline. Another set of data that is of relevance is what is called the Net Investment Position: this is in fact the total external debt of the country. That information is given in Table 29.6. The international comparison in Table 29.6 is an indicator of indebtedness and hence of vulnerability. The English speaking countries and Finland show heavy foreign investments into their countries and net indebtedness. The level of indebtedness approaches the debt of some developing countries. Of particular concern is the US debt ratio (–22.2%). Fortunately for the US, its currency is a world reserve currency, but it is all a matter of confidence. As soon as some major player, such as OPEC, prices its oil in euros, the US dollar as a reserve currency can lose ground in a matter of years. The debt service would then become burdensome and a rapid decline would be a real possibility. A NEO impact in the indebted countries would have major implications for the main creditor nations that are Japan and Switzerland, followed by countries in Western Europe. A major catastrophic impact of a NEO in the indebted countries, with destruction of factories or real estate could be viewed as a force majeure, and an act of God. When real capital is wiped out, it is the insurance companies who will have to meet the costs. Of course the insurance companies could declare bankruptcy and default on their payment obligations. Such a financial disaster would have cascading multiplier effects. Its global spread would be rapid. It is important to note that whereas financial disasters could have major consequences, the damage or destruction of real capital assets such as power stations could have enormous consequences, as the world has become more reliant on large power sources such as nuclear power stations and hydroelectric dams. Table 29.7 gives information on the world’s 11 largest hydroelectric dams. The destruction of any one of them could cause massive floods as well as disruption of economic life. Small AsteroidsImpact – OzoneSmall NEO could kill the planet via ozone depletionMacCracken ‘7 (Michael C., fellow at the Climate Institute, Ch. 16: The Climatic Effects of Asteroid and Comet Impacts: Consequences for an Increasingly Interconnected Society, in Comet/Asteroid Impacts and Human Society: An Interdisciplinary Approach, SpringLink) During and following an impact, nitric oxide could be created in several ways (Toon et al. 1997), including rapid cooling following dissociation of O2 and N2 by shock waves, in the plume following impact with the surface, as debris ejected ballistically re-entered the atmosphere, and possibly as a result of induced fires. Model simulations and observations following nuclear weapons tests indicate that injection of substantial amounts of nitric oxide into the stratosphere would lead to large-scale ozone depletion (NRC 1975). Considering the effect of an asteroid impact, Birks et al. (2007) calculate that an object of about 0.5 km or greater would lead to significant depletion of the global ozone layer; this estimated diameter is about half that cited by Toon et al. (1997), suggesting that asteroid impacts with only about one-eighth the energy have the potential for devastating global-scale impacts and substantially raising the frequency that such events have likely occurred in the past and should be expected in the future. In that ozone is the primary absorber of solar radiation in the stratosphere (balanced by loss of thermal radiation due mainly to carbon dioxide), the stable vertical structure of the stratosphere could also be disturbed, causing changes in atmospheric circulation and in the concentrations of ozone and other substances. Such depletion would allow UV radiation to pass downward toward the surface, where it could do biological harm if not otherwise absorbed by other substances. Nitric oxide injected into the lower atmosphere would also interact chemically, although the lack of light would diminish its role in ozone formation and the suppression of precipitation might slow its removal in rain. Ultimately, however, the nitric oxide (probably in the form of nitric acid) would be likely to be removed from the atmosphere and would tend to acidify water bodies and harm remaining vegetation. Despite many limitations in our understanding, the Earth’s climatic history and model simulations indicate that the impact of a large asteroid or comet would have globalscale effects on climate, which would, in turn, very adversely impact the environment and many key societal activities. While an individual might well have a chance of surviving, the impacts would be such as to make it very difficult for societies to function, leading to very large numbers of secondary deaths (even aside from direct effects of blasts, tsunamis, etc.). That mass extinctions would result from the largest impacts appears quite plausible. Ozone depletion causes complete extinctionGreenpeace ’95 (Full of Holes: Montreal Protocol and the Continuing Destruction of the Ozone Layer -- A GREENPEACE REPORT with contributions from OZONE ACTION -- http://archive.greenpeace.org/ozone/holes/holebg.html) When chemists Sherwood Rowland and Mario Molina first postulated a link between chlorofluorocarbons and ozone layer depletion in 1974, the news was greeted with scepticism, but taken seriously nonetheless. The vast majority of credible scientists have since confirmed this hypothesis. The ozone layer around the Earth shields us all from harmful ultraviolet radiation from the sun. Without the ozone layer, life on earth would not exist. Exposure to increased levels of ultraviolet radiation can cause cataracts, skin cancer, and immune system suppression in humans as well as innumerable effects on other living systems. This is why Rowland's and Molina's theory was taken so seriously, so quickly - the stakes are literally the continuation of life on earth. Directory: files files -> Answer True False 2 points Question 2 files -> Integer programming and game theory files -> 4 Integer Programming files -> Bpa vehicle Window Repair Scenario #1 task: Procure vehicle window relacement. Objective files -> Pop Warner History files -> North Carolina Inclusion Initiative Mapping Where Children with ieps are Being Served Purpose files -> Fall 2013 Spring 2014 Program Data: Standard 1 Exhibit 4d files -> Hanban – asia society confucius classrooms network 2010 request for proposal files -> Northern England’s set-jetting locations Download 1.03 Mb. Share with your friends:
|