THE SCIENCE oF GLOBAL WARMING: > 자유게시판

For those believing that global warming is accepted by most scientists as leading towards what Clive James mischievously referred to as the bodies of fried polar bears floating past your penthouse windows, they could do worse than read James Hogan’s book, "Kicking the Sacred Cow" and see just how many scientists wish to question the mainstream view and why. Those who keep watch on the hurricanes do not observe a present trend towards fiercer hurricanes and many scientists claim that while some areas are currently devastated in some form or other this is not new, even if population increase and redistribution finds more people currently affected than was the case in the past. For example removing trees in areas towards the poles is thought to have a cooling effect since it exposes white snow which then reflects sunlight back into space. Conversely, areas where too much warmth damages crops are adversely affected by increased temperature.

This has implications for the current mainstream acceptance of the carbon dioxide effect since we are currently on just beginning to shift from the 11.1 year sun spot cycle where atmospheric carbon dioxide appears to have had a measurable relationship to temperature and we are now moving to the verge of a more extreme cycle where the carbon dioxide effect is relatively poorly known. Although it is the gases like water, methane and carbon dioxide which are the energy trappers, when we measure temperature it is predominantly the gas molecules which have collided with these energised molecules that are the ones being measured. Complications abound. For example there is a serious contention in the current scientific literature that having greenhouse gases like carbon dioxide in the air may even be lowering global temperature since air warmed by the greenhouse effect at ground level rises during the day to a height where the heat can be dissipated into space at night. For example the scientific consensus is that for the last few centuries there has been widespread evidence of some climate warming and it is also clear that some molecular forms like the well publicised greenhouse gases of carbon dioxide and methane may well help the atmosphere trap heat.

The most recent few years’ record is a little embarrassing right now in view of the apparent recent agreement about warming in the scientific community, and that is that the steep increase in global temperatures through the 1980s and 1990s has now effectively flat-lined despite the steady increase of carbon dioxide and other greenhouse gases in the last ten years. The anthropogenic (human produced) contribution is much more uncertain since other gases like water, ozone, nitrogen oxides, methane, CFCs and various sulfur compound aerosols also impact on the atmosphere’s ability to hold heat, and depending on what stage the Sun has reached in terms of its longer term cycles, the atmosphere itself plays a variable role. Modern smogs in large cities are often toxic with nitrogen dioxide from cars reacting with the other chemicals from produced by various processes to produce a particularly nasty soup called PAN (peroxyacyl nitrate for the chemically literate). Since more carbon dioxide is produced by a variety of oxidation processes at higher temperatures and since more carbon dioxide can be trapped by the sea at lower temperatures temperature affects should be reflected in changing carbon dioxide levels without necessarily being a prime causal factor.

From this combined record we note at times in the relatively recent past, temperatures have been considerably higher than today, and occasionally, temperatures were far colder. That famous graph which became the key rallying picture for the Kyoto summit, was based on very limited sampling and not only purported to plot unprecedented recent global temperature rises - but was extrapolated in a variant of an exponential curve to predict which was said by its author Michael Mann to represent runaway global warming. For those of us brought up with familiarity with graphs from simplistic school laboratory experiments, those comforting and precise looking lines plotting temperature change over millions of years, What is 3c billiards or even plots of recent temperatures or carbon dioxide levels with time convey an implied accuracy of measurement which is quite unwarranted. When it comes to sea level, measurement problems confound those trying to find out what is happening. Temperature measurement in the atmosphere is hard to interpret since above average temperatures higher in the atmosphere might correspond with lower than average temperatures nearer ground level and vice versa. One of the most embarrassing global warming glitches occurred when the IPCC announced with gloomy satisfaction that October 2008 had been the warmest October for world temperatures on record.