This global view of the Arctic Ocean, captured using advanced radar that sees through all weather conditions, is enabling researchers to determine how global warming may be affecting the Polar Ice Cap. The Arctic sea ice is providing clues to the Earth's overall climatic condition.
During the Cenozoic Era, the continents that formed Pangea, the super continent, had begun to move into their present positions. As these continents drifted northward, they formed the shoreline of the Arctic Ocean, which lies directly over and around the geographic North Pole.
About 15 million years into the Cenozoic Era (about 50 million years ago), the Arctic Ice Cap formed over the Arctic Ocean, virtually covering the entire sea with a sheet of ice. As the continents continued to move, climatic changes brought about by shifts in water and air currents caused the Earth to gradually cool down. This created the glaciers that mostly dominated the land masses through the end of the Great Ice Age in the Pleistocene Epoch, about 10,000 to 1.8 million years ago, and that still exist today on Greenland.
The same climatic conditions that created the glaciers, which are essentially great ice sheets formed on land, also formed the Arctic Ice Cap. Yet the ice sheet covering the Arctic Ocean rests directly on top of the ocean instead of land, and it has remained relatively stable and frozen since it was formed...
The Arctic Ice Cap is shrinking dramatically. Roughly the size of the United States, it has lost an area roughly the combined size of Massachusetts and Connecticut each year since the late 1970s. Since the 1950s, when data was first collected on the Arctic, the ice cap has lost nearly 22 % of its volume. It is projected that in another 50 years, nearly half of the Arctic Ice Cap will be gone.
So what is going on? We know that the Arctic Ice Cap, frozen for 50 million years, is melting. We also know that above normal Arctic temperatures from the ocean water to the air currents account for the melting. Global warming is real, and the melting of the Arctic Ice Cap is one of its symptoms.
Scientists have determined that the Earth's surface temperature has increased an average of 1 °F since the beginning of the 20th century, which is enough to trigger significant global climatic changes. According to the United States Environmental Protection Agency (EPA), the 20th century was the warmest century of the last millennium, and the 1990s was the warmest decade. Increased average temperatures have been recorded in both the southern and northern hemispheres, although some regions have recorded cooler temperatures.
Using the best available data, many scientists believe this warming trend will cause an additional 5 - 10 °F increase in the average global temperature in the next century. Still, there are many scientists who believe the global warming trend may reverse itself within the next century. The fact is, there is not enough known about WHY the climate is changing the way it is for scientists to determine what really is going on or what will happen in the future.
But there is enough information to tell us several things.
1. Human activity, such as the burning of fossil fuels, is releasing enormous volumes of carbon dioxide and other greenhouse gases that are contributing to the Earth's natural greenhouse effect, the Earth's natural process of trapping the sun's warmth. About 5 - 6 billion tons of carbon dioxide are emitted each year due to human activity. This increase results in additional heat being trapped within the Earth's atmosphere.
2. The Polar Ice Cap itself reflects sunlight energy (heat) back into space, rather than the heat being absorbed by the Earth. This is called albedo, the amount of sunlight reflected by an object. As the Ice Cap melts however, the albedo is reduced and the Earth absorbs the energy that is not reflected. Thus, more heat is retained in the Arctic.
3. The Earth's natural carbon cycling process the amount of carbon dioxide that enters and leaves the atmosphere as a result of the natural cycle of water exchange from and back into the sea and plants account for about 95 % of the carbon dioxide in the atmosphere which contributes to the greenhouse effect.
4. Ocean waters constantly move along a giant oceanic conveyer belt, which travels, from the North Atlantic to the Atlantic, Pacific and Indian Oceans. This circulation distributes warm tropical waters northward, which are then chilled and returned to the warmer southern oceans. This heat exchange also has a significant impact on global weather patterns.
Ocean waters are constantly on the move, carrying warmer waters north toward the Arctic and cooler waters south to the temperate and tropical zones. This ocean circulation is referred to as the great oceanic conveyer belt, which is a single continuous current that carries chilled water from the North Atlantic into the Atlantic, Indian and Pacific basins. The conveyer belt returns water warmed in the tropics back to the North Atlantic.
Ocean currents also affect global heat exchange by redistributing heat, especially in coastal regions. In fact, the oceans have the greatest impact on the Earth's climate.
PUTTING IT ALL TOGETHER
The point is that while all of these things are taking place at the same time none of them exists in a vacuum. They are all interrelated and can have a reciprocating effect on each other. To what extent, scientists do not know at this point.
The climatic changes that are taking place can have profound impacts on the Earth's ecosystems, human health, plant and animal species. Scientists fear that continued melting of sea ice could weaken the North Atlantic Current, the northward continuation of the Gulf Stream. The Gulf Stream transports 25 times more water than all the Earth's rivers, and a diversion could result in extremely cold winters in the North Atlantic regions, especially in northern Europe.
There are many-fold scenarios; however, human-induced global warming is one that we should pay close attention to because we can control it. If we can reduce carbon-dioxide emissions, it could have a penetrating effect on the natural climatic occurrences that have been affected by human activity. Scientists project that the amount of carbon dioxide released into the atmosphere in the next 30 years will double or triple. The number of cars in operation around the world will double by the year 2030.
ARCTIC ICE DELUGE
One concern that most people have with regard to the melting of the Arctic Ice Cap is the eventual flooding of the landmasses. What is commonly misunderstood is that the Arctic Ice Cap is relatively thin, about 10 feet thick on average.
And about 90 % of that is already displacing the water (taking up space that would otherwise be occupied by water). Thus, even a complete melting of the Arctic Ice Cap would only result in a small increase in sea water level.
Antarctica is a continental landmass 98 % covered by thick ice sheets. It contains 70 % of Earth's fresh water and 90 % of Earth's ice. The average ice thickness is 1.5 miles, reaching 3 miles deep in some regions.
The major concern, however, would be the increase of fresh, cold water into the marine environment. This would alter ecosystems and the food chain dependent on the saline waters would funnel more cold water into the oceanic conveyer belt. As a result, you would see a global climate change due to the introduction of the additional cold water into the southern oceans, and you would see a displacement of plant and animals species dependent on the more saline ecosystems. Some animal species will, of course, retreat to the land-based ecosystems.
TRACKING AIR POLLUTION FROM SPACE
NASA's Terra spacecraft is providing scientists the most complete view of global pollution. Terra sees C in the atmosphere from 2 - 3 miles above the surface, where it interacts with other gases and forms ozone.
NASA's Terra Spacecraft has assembled the first ever-complete view of the world's air pollution as it treks around the globe. Terra's new global air pollution monitor, contributed by the Canadian Space Agency, allows scientists to identify the major sources of air pollution and see what happens to it anywhere on the planet.
Terra is one of the United State's major Earth-observing satellite systems (EOS), designed for the accumulation of data needed to predict future changes in the global environment.
It takes pictures with digital cameras, about 435 miles (700 km) above the Earth, basically to catch reflected sunlight and released heat on or from the Earth, rather than scanning the global surface by microwaves.
Unlike other satellites, Terra travels in a North-South polar orbit.
Through Terra, which launched in December 1999, air pollution is clearly identified as a global problem, with pollution from sources in one region having a dramatic impact on others. Among the greatest impacts observed so far there is the transcontinental drift of an immense carbon monoxide plume from a source in South-east Asia across the Pacific to North America. The pollution reaches North America in fairly high concentrations. In the winter, a major source of pollution captured by Terra is the burning of fossil fuels for mass transportation and business and residential heating in the northern regions of the planet, which is observed traversing a majority of the hemisphere.
A NEW LOOK AT HUMAN EXTINCTION
The very powerful technologies of the new Millennium - from robotics, genetic engineering and nanotechnologies - "are threatening to make humans an endangered species," according to the April 2000 issue of
"Wired Magazine" ("Why the Future Doesn't Need Us") in an article by Billy Joy, co-founder and chief scientist of Sun Microsystems. As man's dependence on technology continues to substantially increase, so does his progress in developing intelligent machines that can and will do all things better than humans can do them-selves. In a way, it is the technological version of Charles Darwin's "survival of the fitted." If technological evolution reaches the point where sophisticated systems of machines can function on a cognitive level, and make decisions and perform tasks without the need for any human intervention whatsoever, then, as Mr. Joy points out, the human race would be at the mercy of machines.
So, why doesn't the future need us? Mr. Joy covers this possibility in extraordinary thought which considers a simple theme in our efforts to improve the quality of our lives, we - humans - strive to make things that can do things better than we can ourselves. In so doing, we create things that replace what humans once did exclusively. Just consider such simple creations as the calculator, remote control devices, personal computers and microwave ovens.
Yet, the 21st century will provide such compelling technologies as genetic engineering and nanotechnologies (work at the atomic, as opposed to the molecular level) that have the potential to threaten any human involvement whatsoever - far more than the simpler technologies of yore. According to Joy, "Specifically, robots, engineered organisms, and nanobots (robots on the atomic level) share a dangerous amplifying factor: they can self-replicate. A bomb is blown up only once - but one can become many, and quickly get out of control." And the risk of this would be substantial damage to the physical world, the environment on which humans and all of
Earth's other organic co-inhabitants depend.
The promises of these new technologies are equally powerful: virtual immortality, providing treatments and cures for almost every disease, and solutions and advances that could expand the human life span indefinitely and improve the quality of our lives - particularly the environment. All the while, Joy says, "with each of these technologies, a sequence of small, individually sensible advances leads to an accumulation of great power, and, concomitantly [coupled with], real danger."
Simply getting rid of machines would be suicide, Joy points out. So perhaps an equally viable option is that human progress be tempered with the care of ensuring that human involvement remains essential to that progress, thereby ensuring that human needs are maintained and the quality of life improved. While it's true that machines and other products of our technologies have no consciousness, it does not mean that they will not some day have the cognitive qualities to perform tasks as humans do. Today, that is called science fiction.
But as we have learned from our science fiction literature of the past, such things are based on real possibilities, many of which we have already witnessed in our lifetime, such as space travel, visiting other planets, the creation of the atomic bomb, nuclear power and machines that will talk to you. Perhaps English author H.G.
Wells, considered by many to be the father of modern science fiction, could foresee such human decline "at a time when civilization passes it zenith," when he authored his first literary work, "The Time Machine" in 1895.
In speaking of the result of human progress witnessed far into the future by the Time Traveler, he wrote: "The great triumph of Humanity I had dreamed of took a different shape in my mind. It had been no such triumph of moral education and general co-operation as I had imagined. Instead, I saw a real aristocracy, armed with a perfected science and working to a logical conclusion the industrial system of today. Its triumph had not been simply a truth over Nature, but a triumph over Nature and the fellow man."
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