The images show the ice cap as it was in 1979 and the ice cap in 2003.
Top Ice cap, 1979; bottom 2003
The shrinkage corresponds to consecutive minimal records being set throughout the 1990s, with the year 1991 being the only exception to the pattern (when Mount Pinatubo erupted in the Phillipines, spewing ash into the atmosphere, which temporarily cooled the arctic - this event also illustrates just how sensitive the global climate is to emissions in the atmosphere).
In the last two decades, temperatures have been rising in the arctic at a rate 20 times faster than the warming that occured over the previous century, and the thickness of the ice sheet has decreased by about half (down from 15 feet in the 1980s to 8 feet in 2003). Springs are coming earlier, and fall is arriving later, which combined with higher summer temperatures year after year contributes to the gradual shrinking of the permanent ice sheet. Surface temperatures are increasing at a rate of 2 degrees per decade over the region, and the result is pooling of liquid water on the surface of the ice sheets. Because water absorbs heat (rather than reflecting most of the radiation, as ice does) this results in accelerated ice melt, and also causes deep fractures to develope in ice shelves and glaciers, leading to such events as the splitting of the Ward Ice Shelf last month, and eventually to ice berg calving events, as the the ice sheet splits along this fissures. Arctic sea ice set a new record for minimum size in 2002.
Sea temperature anomolies, October 21st, 2003
The sea temperature anomoly map continues to show unusually warm water in arctic region at the end of October, with the scale being light yellow about a degree or less warmer than normal, the oranges representing 2 or 3 degrees warmer than normal, and the reds indicating 4 or 5 degrees warmer than normal. An archive of sea temperature anomoly maps is online which goes back to 1984. What these maps reveal is that during the 80s and early 90s, there were temperature anomolies of only about one half to one degree in scattered spots around the arctic during the month of October, and then around 1997 dramatic differentials begin to appear (as much as 4 or 5 degrees warmer than normal).
Warming in the arctic should be expected to take place with increasing speed once a certain threshold has been crossed (one can imagine rather than a smooth continuous graph, there would be a graph which for some time follows almost a straight line moving upward slowly and then once the threshold has been crossed, begins to curve upward dramatically - in short, if warming of the arctic is thought of as a curve on a graph, it should be expected to resemble the curve of a function that increases exponentially...the reason why this would be the case is that ice reflects almost all the energy it receives back into space, while water absorbs energy, and thus warms...as the ice decreases, the surface area of water increases, and thus the amount of warming increases due to this increased absorption...therefore the rate of warming begins to increase dramatically and the melting of the ice cap occurs at ever increasing speeds...given that the rate of warming has increased to 20 times the rate of the previous century, you can well imagine the exponential increase of the curve if the rate of increase was plotted on a graph, and as the ice sheet continues to retreat, this rate of warming can be expected to continue to increase - the curve would climb upward - and the real world analogue would be ever more rapid retreat of the ice cap). One of the criticism leveled at current climate change computer software is that it models climate change as taking place gradually, when the historical record indicates that climate changes suddenly. See also : Arctic Ice Melting Much Faster Than Thought.
The retreat of the arctic ice cap has global ramifications, and given the complexity of the climate, and its sensitivity to even small changes (such as the eruption of Pinatubo as just one example) it is difficult for scientists to given unqualified predictions of just what the effects on the global climate will be in response to these changes taking place in the arctic. Both the atmospheric currents and the ocean currents can be expected to change, and this is already some research would suggests that the changes in the arctic affect such weather events as rainfall in far away Africa.
It surprises me that there are those who say, 'I don't believe in Global warming.' The graph of global temperature increase shows a particularly sharp increase beginning in the 1970s (it is beginning to display the characteristics of an exponential curve, with a period of gradual increase, followed by a sharp upward turn in the graph). Global warming is a fact, and if people remain ignorant of this fact it can only be due to propaganda which originates with special interest groups. The amount of CO2 in the atmosphere has increased by one third during the fossil fuel age, and I find it remarkable that there are those who would suggest that an increase in greenhouse gas of this magnitude could not possibly result in a change in the global climate. For example, they will try to suggest that this change is 'part of the natural variability of the climate' or they will blame it on 'an increase in the sun's energy level'. How could the amount of greenhouse gas increase by a third, and global warming occur, and yet still their is all this disputation concerning the cause of the warming that is occuring?
Global warming is not controversial science (or at least it should not be) and similarly the cause of the warming (increased greenhouse gases) should not be controversial, and probably would not be, if it were not for the fact that a multi-trillion dollar industry fuels and funds the controversy. What is controversial is what the effects of this ongoing global warming will be. No one can say for certain what the new climate of the planet will be like, since climate is extremely complex, as well as being extremely sensitive. Climate change is a gamble, and the unfortunate thing is that like in all gambling, if anyone suffers a loss, there is no way to begin again.
If greenhouse gases were not present in the atmosphere, the average temperature of the earth would be 0 degrees. Most of the planet would not be able to support life as we know it, with the exception of a narrow band close to the equator. Venus is a planet about the size of the earth, with an atmosphere composed almost entirely of greenhouse gases, and the temperature on Venus is about 500 degrees Celsius (which is over 900 degrees Fahrenheit), and this is a remarkable example of the Greenhouse effect run wild. Greenhouse gases allow the energy from the sun to reach the earth. Here the energy is transformed into heat (infrared radiation) which is then reflected back towards space. Greenhouse gases are not transparent to infrared radiation and so this heat energy is then reflected back to earth (the greenhouse effect) and it is this concentration of greenhouse gas that is responsible for the Earth having a climate which is conducive to life (and the extreme density of greenhouse gases in the atmosphere of Venus traps so much infrared energy that Venus is a hell compared to the heaven of Earth). An increase of greenhouse gases in the Earth's atmosphere of one third is not insignificant, and when we see that global warming is taking place, attributing the cause to 'natural variability' or 'an increase in the sun's energy' is the least reasonable hypothesis when there has been an increase of one third in the amount of greenhouse gases in the atmosphere, which would result in global warming by definition, and global warming is what is taking place, as one would expect.
That the climate is changing is obvious, not only when considering one regional change taking place (in the Arctic) but when examining what is happening on a global scale (it is hardly likely that such global changes would be unrelated). For example, a similar process of disintegration of the ice cap and the ice shelves is taking place in Antarctica. It was around 1997 that the warming trend in the Arctic waters began to accelerate (as revealed by the anomolous temperature map archive). It was also at this time that changes in the climate in Northern Africa began to occur. Just a new records for minimal ice cover were set yearly in the Arctic, new records for rainfall in Northern Africa began to occur during the same decade, and this year such strange events occured as having the rivers in the region swollen with eight times as much water as would be expected. In Timbuktu on the Sahara, a United Nations heritage site, elaborate mud brick structures as much as 600 years old melted in the torrential downpours that took place this year.
Scientific surveys have indicated that the Sahara desert is retreating. One theory concerning global warming holds that one of the results should be the rejevenation of what is now the Sahara desert. The reason for this conclusion is that only 6,000 years ago, when the global climate was only a degree warmer than in the following millenia, the Sahara was fertile, rivers ran through it, and fossilized remains of a wide variety of African wildlife remain from this previous time. 'Global cooling' of only a single degree was enough to change global atmospheric and ocean currents, which resulted in a changed climate in which the Sahara became a massive desert, one of the stable features of the world's climatic regime for the last six thousand years.
Opportunistic desert grasses make the most of the opportunity presented by rains to temporarily grow, and then disappear. (These sorts of plants produce seeds that can lie dormant for a long time, making them perfectly adapted to the conditions in a desert). Now as plants live and die, the conditions are established that will eventually allow colonisation by other plants, since it is dead plants that produce humus, and thus build soils. Anyone who has ever seen the farm land on what used to be the Savannahs of the North American plains, will be familiar with the extremely thick layer of top soil that has existed on the plains, which was produced by generations of grasses and other plants over many thousands of years.
One usual feature over the Sahara this year has been the persistance of preciptable water over Sahara, as well as the appearance of low pressure systems. The map below shows the Totals/Totals index, with the darkest browns indicating the largest amounts of precipitable water in the atmosphere. This feature appeared over the Western half of the Sahara, and is now present over the Eastern Sahara, and this, along with the appearance of low pressure systems, is highly unusual (note that as of today, Tuesday, October 28, 2003) this anomalous band of precipitable water has once again moved into the Western Sahara). These changes have been pronounced since the late 1990s, and just as the tempo of change in the Arctic has been increasing, so the tempo of change in the Saharan region has been increasing year after year.
Other changes of note include the breaking of temperature records in the American west this fall, as well as record breaking numbers of tornadoes and wind storms earlier this year (the rising global temperatures have resulted in a ten per cent increase in global humidity levels over the last decade due to increases in evaporation- and water in the atmosphere is another potent greenhouse gas - so as the process continues it also accelerates - and increased humidity causes more tornadoes of increasing severity). Also very significant is the world wide retreat of mountain glaciers, which, over time, means the end of rivers, which are fed by mountain glaciers, and just how people plan to get by without these rivers is a good question...but apparently they don't spend a lot of time thinking about it, and even if they did, it would require drastic action to stop the process of global warming, and thus save the planet from convulsing and dying of thirst in the times to come (to even begin to hold the climate steady and save those all important glaciers, and those ever so important rivers and lakes which are very neccesary sources of fresh drinkingwater) this would require reductions in CO2 emissions of at least 60 per cent, according to current scientific consensus. Now given how people shot the buffalo until no buffalo were left, and how they hack down the old growth rainforests until not a spot is left (in British Columbia they are presently ruining the last habitat of the spotted owl and the rare barking salamander), well considering all this I would assume that they will just find 'economic reasons' to continue doing what they are doing, and just deal with that other problem of dying of thirst later on when it becomes a more immediate and pressing concern...
But then this is one of the problems of having people become socialized in a 'free market economy'. This type of fiercely competitive, dog eat dog, everyone for themselves, compete or die Social Darwinism, while it is always hyped as 'bringing out the best in people' (by throwing them into fierce competition with each other) actually brings out the worst in people, causes them fear for their survival, live in fear of having the economic rug pulled out from under them (at which time, they, being the losers in the battle of the 'survival of the economic fittest' can then become homeless under a bridge) well this kind of thinking causes people to bust up into feuding special interest groups,filled with anger and fury, whose only thought is to 'battle' and 'defeat' their 'competition'. Furious loggers against angered environmentalists, as just one example, and those loggers will definately do the buffalo thing on those forests, and the whole planet will definately commit suicide by dying of thirst by melting all those damn glaciers. They will do it, because they can't do anything else. They are free marketeers, and that system does not bring out the best in people, but rather the very worst. When you hear about 'ethnic cleansing' (where one group battles another over resources) what you are actually seeing is just 'free marketeering' stripped of its veneer of so called 'cvilization' (for example, the 'civilized' way of committing acts of ethnic cleansing, would be to destroy your rivals business and thus capture his market share...this will of course leave him and all his employees completely ruined, but then, to the victors go the spoils, and as to what happens to them afterwards, well that's their problem). Naturally given what a worthless system we live under, and what it does to destroy the human soul, I think we can all look forward to watching those forests burn to the ground, while the ice caps disappear and flood islands and coasts, while the rivers continue to disappear and people then feud with each other over precious water (will they finally have to shut down all barge traffic on the Mississipi next year - this year the barges are only half full to avoid scraping bottom - and the Great Lakes have dropped another foot - that one foot equals years of glacier build up, by the way, and the glaciers are not building up, they are shrinking...)
