The Carbon Dioxide Greenhouse Effect

In the 19th century, scientists realized that gases in the atmosphere cause a "greenhouse effect" which affects the planet's temperature. These scientists were interested chiefly in the possibility that a lower level of carbon dioxide gas might explain the ice ages of the distant past. At the turn of the century, Svante Arrhenius calculated that emissions from human industry might someday bring a global warming. Other scientists dismissed his idea as faulty. In 1938, G.S. Callendar argued that the level of carbon dioxide was climbing and raising global temperature, but most scientists found his arguments implausible. It was almost by chance that a few researchers in the 1950s discovered that global warming truly was possible. In the early 1960s, C.D. Keeling measured the level of carbon dioxide in the atmosphere: it was rising fast. Researchers began to take an interest, struggling to understand how the level of carbon dioxide had changed in the past, and how the level was influenced by chemical and biological forces. They found that the gas plays a crucial role in climate change, so that the rising level could gravely affect our future.

Like many Victorian natural philosophers, John Tyndall was fascinated by a great variety of questions. While he was preparing an important treatise on "Heat as a Mode of Motion" he took time to consider geology. Tyndall had hands-on knowledge of the subject, for he was an ardent Alpinist (in 1861 he made the first ascent of the Weisshorn). Familiar with glaciers, he had been convinced by the evidence — hotly debated among scientists of his day — that tens of thousands of years ago, colossal layers of ice had covered all of northern Europe. How could climate possibly change so radically?

One possible answer was a change in the composition of the Earth's atmosphere. Beginning with work by Joseph Fourier in the 1820s, scientists had understood that gases in the atmosphere might trap the heat received from the Sun. As Fourier put it, energy in the form of visible light from the Sun easily penetrates the atmosphere to reach the surface and heat it up, but heat cannot so easily escape back into space. For the air absorbs invisible heat rays (“infrared radiation”) rising from the surface. The warmed air radiates some of the energy back down to the surface, helping it stay warm. This was the effect that would later be called, by an inaccurate analogy, the "greenhouse effect." The equations and data available to 19th-century scientists were far too poor to allow an accurate calculation. Yet the physics was straightforward enough to show that a bare, airless rock at the Earth's distance from the Sun should be far colder than the Earth actually is.
Tyndall set out to find whether there was in fact any gas in the atmosphere that could trap heat rays. In 1859, his careful laboratory work identified several gases that did just that. The most important was simple water vapor (H2O). Also effective was carbon dioxide (CO2), although in the atmosphere the gas is only a few parts in ten thousand. Just as a sheet of paper will block more light than an entire pool of clear water, so the trace of CO2 altered the balance of heat radiation through the entire atmosphere.

Greenhouse Speculations: Arrhenius and Callendar

The next major scientist to consider the question was another man with broad interests, Svante Arrhenius in Stockholm. He too was attracted by the great riddle of the prehistoric ice ages. In 1896 Arrhenius completed a laborious numerical computation which suggested that cutting the amount of CO2 in the atmosphere by half could lower the temperature in Europe some 4-5°C (roughly 7-9°F) — that is, to an ice age level. But this idea could only answer the riddle of the ice ages if such large changes in atmospheric composition really were possible. For that question Arrhenius turned to a colleague, Arvid Högbom. It happened that Högbom had compiled estimates for how carbon dioxide cycles through natural geochemical processes, including emission from volcanoes, uptake by the oceans, and so forth. Along the way he had come up with a strange, almost incredible new idea.
It had occurred to Högbom to calculate the amounts of CO2 emitted by factories and other industrial sources. Surprisingly, he found that human activities were adding CO2 to the atmosphere at a rate roughly comparable to the natural geochemical processes that emitted or absorbed the gas. The added gas was not much compared with the volume of CO2 already in the atmosphere — the CO2 released from the burning of coal in the year 1896 would raise the level by scarcely a thousandth part. But the additions might matter if they continued long enough.(2) (By recent calculations, the total amount of carbon laid up in coal and other fossil deposits that humanity can readily get at and burn is some ten times greater than the total amount in the atmosphere.) So the next CO2 change might not be a cooling decrease, but an increase. Arrhenius made a calculation for doubling the CO2 in the atmosphere, and estimated it would raise the Earth's temperature some 5-6°C.
Arrhenius did not see that as a problem. He figured that if industry continued to burn fuel at the current (1896) rate, it would take perhaps three thousand years for the CO2 level to rise so high. Högbom doubted it would ever rise that much. One thing holding back the rise was the oceans. According to a simple calculation, sea water would absorb 5/6ths of any additional gas. (That is roughly true over a long run of many thousand years, but Högbom and Arrhenius did not realize that if the gas were emitted more rapidly than they expected, the ocean absorption could lag behind.) Anyway temperatures a few degrees higher hardly sounded like a bad idea in chilly Sweden. Another highly respected scientist, Walter Nernst, even fantasized about setting fire to useless coal seams in order to release enough CO2 to deliberately warm the Earth's climate.
Arrhenius brought up about the possibility of future warming in an impressive scientific article and a widely read book. By the time the book was published, 1908, the rate of coal burning was already much higher than in 1896, and Arrhenius suggested warming might appear wihin a few centuries rather than millenia. Yet here as in his first article, the possibility of warming in some distant future was far from his main point. He mentioned it only in passing, during a detailed discussion of what really interested scientists of his time — the cause of the ice ages. Arrhenius had not quite discovered global warming, but only a curious theoretical concept.

An American geologist, T. C. Chamberlin, and a few others took an interest in CO2. How, they wondered, is the gas stored and released as it cycles through the Earth's reservoirs of sea water and minerals, and also through living matter like forests? Chamberlin was emphatic that the level of CO2 in the atmosphere did not necessarily stay the same over the long term. But these scientists too were pursuing the ice ages and other, yet more ancient climate changes — gradual shifts over millions of years. Very different climates, like the balmy age of dinosaurs a hundred million years ago, puzzled geologists but seemed to have nothing to do with changes on a human time scale. Nobody took much interest in the hypothetical future warming caused by human industry.
Experts could dismiss the hypothesis because they found Arrhenius's calculation implausible on many grounds. In the first place, he had grossly oversimplified the climate system. Among other things, he had failed to consider how cloudiness might change if the Earth got a little warmer and more humid.A still weightier objection came from a simple laboratory measurement. A few years after Arrhenius published his hypothesis, another scientist in Sweden, Knut Ångström, asked an assistant to measure the passage of infrared radiation through a tube filled with carbon dioxide. The assistant ("Herr J. Koch," otherwise unrecorded in history) put in rather less of the gas in total than would be found in a column of air reaching to the top of the atmosphere. The assistant reported that the amount of radiation that got through the tube scarcely changed when he cut the quantity of gas back by a third. Apparently it took only a trace of the gas to "saturate" the absorption — that is, in the bands of the spectrum where CO2 blocked radiation, it did it so thoroughly that more gas could make little difference.
Still more persuasive was the fact that water vapor, which is far more abundant in the air than carbon dioxide, also intercepts infrared radiation. In the crude spectrographs of the time, the smeared-out bands of the two gases entirely overlapped one another. More CO2 could not affect radiation in bands of the spectrum that water vapor, as well as CO2 itself, were already blocking entirely.
These measurements and arguments had fatal flaws. Herr Koch had reported to Ångström that the absorption had not been reduced by more than 0.4% when he lowered the pressure, but a modern calculation shows that the absorption would have decreased about 1% — like many a researcher, the assistant was over confident about his degree of precision.But even if he had seen the1% shift, Ångström would have thought this an insignificant perturbation. He failed to understand that the logic of the experiment was altogether false.
The greenhouse effect will in fact operate even if the absorption of radiation were totally saturated in the lower atmosphere. The planet's temperature is regulated by the thin upper layers where radiation does escape easily into space. Adding more greenhouse gas there will change the balance. Moreover, even a 1% change in that delicate balance would make a serious difference in the planet’s surface temperature. The logic is rather simple once it is grasped, but it takes a new way of looking at the atmosphere — not as a single slab, like the gas in Koch's tube (or the glass over a greenhouse), but as a set of interacting layers.
The subtle difference did not occur to anyone for many decades, if only because hardly anyone thought the greenhouse effect was worth their attention. For after Ångström published his conclusions in 1900, the few scientists who had taken an interest in the matter concluded that Arrhenius's hypothesis had been proven wrong. Theoretical work on the question stagnated for decades, and so did measurement of the level of CO2 in the atmosphere.
A few scientists dissented from the view that changes of CO2 could have no effect. An American physicist, E.O. Hulburt, pointed out in 1931 that investigators had been mainly interested in pinning down the intricate structure of the absorption bands (which offered fascinating insights into the new theory of quantum mechanics) "and not in getting accurate absorption coefficients." Hulburt's own calculations supported Arrhenius's estimate that doubling or halving CO2 would bring something like a 4°C rise or fall of surface temperature, and thus "the carbon dioxide theory of the ice ages... is a possible theory."Hardly anyone noticed this paper. Hulburt was an obscure worker at the U.S. Naval Research Laboratory, and he published in a journal, the Physical Review, that few meteorologists read. Their general consensus was the one stated in such authoritative works as the American Meteorological Society's 1951 Compendium of Meteorology: the idea that adding CO2 would change the climate "was never widely accepted and was abandoned when it was found that all the long-wave radiation [that would be] absorbed by CO2 is [already] absorbed by water vapor."
Even if people had recognized this was untrue, there were other well-known reasons to deny any greenhouse effect in the foreseeable future. These reasons reflected a nearly universal conviction that the Earth automatically regulated itself in a "balance of nature." Getting to specifics, scientists repeated the plausible argument that the oceans would absorb any excess gases that came into the atmosphere. Fifty times more carbon is dissolved in sea water than in the wispy atmosphere. Thus the oceans would determine the equilibrium concentration of CO2, and it would not easily stray from the present numbers.
If somehow the oceans failed to stabilize the system, organic matter was another good candidate for providing what one scientist called "homeostatic regulation."The amount of carbon in the atmosphere is only a small fraction of what is bound up not only in the oceans but also in trees, peat bogs, and so forth. Just as sea water would absorb more gas if the concentration increased, so would plants grow more lushly in air that was "fertilized" with extra carbon dioxide. Rough calculations seemed to confirm the comfortable belief that biological systems would stabilize the atmosphere by absorbing any surplus. One way or another, then, whatever gases humanity added to the atmosphere would be absorbed — if not at once, then within a century or so — and the equilibrium would automatically restore itself. As one respected expert put it baldly in 1948, "The self-regulating mechanisms of the carbon cycle can cope with the present influx of carbon of fossil origin."

Yet the theory that atmospheric CO2 variations could change the climate was never altogether forgotten. An idea so simple on the face of it, an idea advanced (however briefly) by outstanding figures like Arrhenius and Chamberlin, had to be mentioned in textbooks and review articles if only to refute it. Arrhenius's outmoded hypothesis persisted in a ghostly afterlife.

It found a lone advocate. Around 1938 an English engineer, Guy Stewart Callendar, took up the old idea. An expert on steam technology, Callendar apparently took up meteorology as a hobby to fill his spare time. Many people, looking at weather stories from the past, had been saying that a warming trend was underway. When Callendar compiled measurements of temperatures from the 19th century on, he found they were right. He went on to dig up and evaluate old measurements of atmospheric CO2 concentrations. He concluded that over the past hundred years the concentration of the gas had increased by about 10%. This rise, Callendar asserted , could explain the observed warming. For he understood (perhaps from Hulburt's calculation) that even if the CO2 in the atmosphere did already absorb all the heat radiation passing through, adding more gas would change the height in the atmosphere where the absorption took place. That, he calculated, would make for warming.
As for the future, Callendar estimated, on flimsy grounds, that a doubling of CO2 could gradually bring a 2°C rise in future centuries. He hinted that it might even trigger a shift to a self-sustaining warmer climate (which did not strike him as a bad prospect). But future warming was a side issue for Callendar. Like all his predecessors, he was mainly interested in solving the mystery of the ice ages.
Callendar's publications attracted some attention, and climatology textbooks of the 1940s and 1950s routinely included a brief reference to his studies. But most meteorologists gave Callendar's idea scant credence. In the first place, they doubted that CO2 had increased at all in the atmosphere. The old data were untrustworthy, for measurements could vary with every change of wind that brought emissions from some factory or forest.Already in the nineteenth century scientists had observed that the level of the gas rose, for example, near a flock of sheep busy exhaling the gas, and dropped in London during the inactivity of a bank holiday. If in fact CO2 was rising, that could only be detected by a meticulous program stretching decades into the future.The objections that had been raised against Arrhenius also had to be faced. Wouldn't the immense volume of the oceans absorb all the extra CO2? Callendar countered that the thin layer of ocean surface waters would quickly saturate, and it would take thousands of years for the rest of the oceans to turn over and be fully exposed to the air. But nobody knew the actual turnover rate, and it seemed that the oceans would have time to handle any extra gases. According to a well-known estimate published in 1924, even without ocean absorption it would take 500 years for fuel combustion to double the amount of CO2 in the atmosphere.
There was also the old objection, which most scientists continued to find decisive, that the overlapping absorption bands of CO2 and water vapor already blocked all the radiation that those molecules were capable of blocking. Callendar tried to explain that the laboratory spectral measurements were woefully incomplete.Gathering scattered observational data, he argued that there were parts of the spectrum where the CO2 bands did not overlap others. Some scientists found this convincing, or at least kept an open mind on the question. But it remained the standard view that, as an official U.S. Weather Bureau publication put it, the masking of CO2 absorption by water vapor was a "fatal blow" to the CO2 theory. Therefore, said this authority, "no probable increase in atmospheric CO2 could materially affect" the balance of radiation.
Most damaging of all, Callendar's calculations of the greenhouse effect temperature rise ignored much of the real world's physics. For example, as one critic pointed out immediately, he only calculated how heat would be shuttled through the atmosphere by radiation, ignoring the crucial energy transport by convection as heated air rose from the surface (this deficiency would haunt greenhouse calculations through the next quarter-century). Worse, any rise in temperature would allow the air to hold more moisture, which would probably mean more clouds. Callendar admitted that the actual climate change would depend on interactions involving changes of cloud cover and other processes that no scientist of the time could reliably calculate. Few thought it worthwhile to speculate about such dubious questions, where data were rudimentary and theory was no more than hand-waving. Better to rest with the widespread conviction that the atmosphere was a stable, automatically self-regulated system. The notion that humanity could permanently change global climate was implausible on the face of it, hardly worth a scientist's attention.

The scientists who brushed aside Callendar's claims were reasoning well enough. (Subsequent work has shown that the temperature rise up to 1940 was, as his critics thought, mainly caused by some kind of natural cyclical effect, not by the still relatively low CO2 emissions. And the physics of radiation and climate was indeed too poorly known at that time to show whether adding more gas could make much difference.) Yet if Callendar was mistaken when he insisted he could prove global warming had arrived, it was a fortunate mistake.

Research by definition is done at the frontier of ignorance. Like nearly everyone described in these essays, Callendar had to use intuition as well as logic to draw any conclusions at all from the murky data and theories at his disposal. Like nearly everyone, he argued for conclusions that mingled the true with the false, leaving it to later workers to peel away the bad parts. While he could not prove that global warming was underway, he had given reasons to reconsider the question. We owe much to Callendar's courage. His claims rescued the idea of global warming from obscurity and thrust it into the marketplace of scientific ideas. Not everyone dismissed his claims. Their very uncertainty attracted scientific curiosity.

Causes of Global Warming

“As human-caused biodiversity loss and climate disruption gain ground, we need to keep our sights clear and understand that the measure of a threat is not a matter of whether it is made on purpose, but of how much loss it may cause. It's an ancient habit to go after those we perceive to be evil because they intended to do harm. It's harder, but more effective, to "go after," meaning to more effectively educate and socialize, those vastly larger numbers of our fellow humans who are not evil, but whose behavior may in fact be far more destructive in the long run." (Ed Ayres, editor of Worldwatch magazine, Nov/Dec 2001)

Carbon Dioxide from Power Plants

In 2002 about 40% of U.S. carbon dioxide emissions stem from the burning of fossil fuels for the purpose of electricity generation. Coal accounts for 93 percent of the emissions from the electric utility industry. US Emissions Inventory 2004 Executive Summary p. 10

Coal emits around 1.7 times as much carbon per unit of energy when burned as does natural gas and 1.25 times as much as oil. Natural gas gives off 50% of the carbon dioxide, the principal greenhouse gas, released by coal and 25% less carbon dioxide than oil, for the same amount of energy produced. Coal contains about 80 percent more carbon per unit of energy than gas does, and oil contains about 40 percent more. For the typical U.S. household, a metric ton of carbon equals about 10,000 miles of driving at 25 miles per gallon of gasoline or about one year of home heating using a natural gas-fired furnace or about four months of electricity from coal-fired generation.
Carbon Dioxide Emitted from Cars

About 33% of U.S carbon dioxide emissions comes from the burning of gasoline in internal-combustion engines of cars and light trucks (minivans, sport utility vehicles, pick-up trucks, and jeeps).US Emissions Inventory 2006 page 8 Vehicles with poor gas mileage contribute the most to global warming. For example, according to the E.P.A's 2000 Fuel Economy Guide, a new Dodge Durango sports utility vehicle (with a 5.9 liter engine) that gets 12 miles per gallon in the city will emit an estimated 800 pounds of carbon dioxide over a distance of 500 city miles. In other words for each gallon of gas a vehicle consumes, 19.6 pounds of carbon dioxide are emitted into the air. [21] A new Honda Insight that gets 61 miles to the gallon will only emit about 161 pounds of carbon dioxide over the same distance of 500 city miles. Sports utility vehicles were built for rough terrain, off road driving in mountains and deserts. When they are used for city driving, they are so much overkill to the environment. If one has to have a large vehicle for their family, station wagons are an intelligent choice for city driving, especially since their price is about half that of a sports utility. Inasmuch as SUV's have a narrow wheel base in respect to their higher silhouette, they are four times as likely as cars to rollover in an accident. [33]
The United States is the largest consumer of oil, using 20.4 million barrels per day. In his debate with former Defense Secretary Dick Cheney, during the 2000 Presidential campaign, Senator Joseph Lieberman said, "If we can get 3 miles more per gallon from our cars, we'll save 1 million barrels of oil a day, which is exactly what the (Arctic National Wildlife) Refuge at its best in Alaska would produce."
If car manufacturers were to increase their fleets' average gas mileage about 3 miles per gallon, this country could save a million barrels of oil every day, while US drivers would save $25 billion in fuel costs annually.
Carbon Dioxide from Airplanes

The UN's Intergovernmental Panel on Climate Change estimates that aviation causes 3.5 percent of global warming, and that the figure could rise to 15 percent by 2050.

Carbon Dioxide from Buildings

Buildings structure account for about 12% of carbon dioxide emissions.
Methane

While carbon dioxide is the principal greenhouse gas, methane is second most important. According to the IPCC, Methane is more than 20 times aseffective as CO2 at trapping heat in the atmosphere. US Emissions Inventory 2004 Levels of atmospheric methane have risen 145% in the last 100 years. [18] Methane is derived from sources such as rice paddies, bovine flatulence, bacteria in bogs and fossil fuel production. Most of the world’s rice, and all of the rice in the United States, is grown on flooded fields. When fields are flooded, anaerobic conditions develop and the organic matter in the soil decomposes, releasing CH4 to the atmosphere, primarily through the rice plants. US Emissions Inventory 2004
Water Vapor in the Atmosphere Increasing

Water vapor is the most prevalent and most poweful greenhouse gas on the planet, but its increasing presence is the result of warming caused by carbon dioxide, methane and other greenhouse gases. (See NOAA's National Climate Data Center (NCDC) FAQ page) Water vapor holds onto two-thirds of the heat trapped by all the greenhouse gases.[129] As the Earth heats up relative humidity is able to increase, allowing the planet's atmosphere to hold more water vapor, causing even more warming, thus a positive feedback scenario. Because the air is warmer, the relative humidity can be higher (in essence, the air is able to 'hold' more water when its warmer), leading to more water vapor in the atmosphere, says the NCDC. There is much scientific uncertainty as to the degree this feedback loop causes increased warming, inasmuch as the water vapor also causes increased cloud formation, which in turn reflects heat back out into space.
Nitrous oxide

Another greenhouse gas is Nitrous oxide (N2O), a colourless, non-flammable gas with a sweetish odour, commonly known as "laughing gas", and sometimes used as an anaesthetic. Nitrous oxide is naturally produced by oceans and rainforests. Man-made sources of nitrous oxide include nylon and nitric acid production, the use of fertilisers in agriculture, cars with catalytic converters and the burning of organic matter. Nitrous oxide is broken down in the atmosphere by chemical reactions that involve sunlight.
Deforestation

After carbon emissions caused by humans, deforestation is the second principle cause of atmospheric carbn dioxide. (NASA Web Site) Deforestation is responsible for 20-25% of all carbon emissions entering the atmosphere, by the burning and cutting of about 34 million acres of trees each year. We are losing millions of acres of rainforests each year, the equivalent in area to the size of Italy. [22] The destroying of tropical forests alone is throwing hundreds of millions of tons of carbon dioxide into the atmosphere each year. We are also losing temperate forests. The temperate forests of the world account for an absorption rate of 2 billion tons of carbon annually. [3] In the temperate forests of Siberia alone, the earth is losing 10 million acres per year.
City Gridlock

In 1996 according to an annual study by traffic engineers [as reported in the San Francisco Chronicle December 10, 1996] from Texas A and M University, it was found that drivers in Los Angeles and New York City alone wasted 600 million gallons of gas annually while just sitting in traffic. The 600 million gallons of gas translates to about 7.5 million tons of carbon dioxide in just those two cities. <>Carbon in Atmosphere and Ocean The atmosphere contains about 750 billion tons of carbon, while 1020 billion tons are dissolved in the surface layers of the world's ocean.

Permafrost

Permafrost is a solid structure of frozen soil, extending to depths of 2.200 feet in some areas of the arctic and subarctic regions, containing grasses, roots, sticks, much of it dating back to 30,000 years. About 25% of the land areas of the Northern Hemisphere hold permafrost, which is defined as soil whose temperature has been 32 degrees Fahrenheit (0 degrees Celsius) for a period of at least 2 years. Permafrost is under 85% of Alaska land surface and much of Canada, Scandinavia and Siberia and holds about 14 per cent of the world's carbon. The hard permafrost on which is built homes and other buildings, can, with rising temperatures, turn into a soft material causing subsidence and damage to buildings, electric generating stations, pipelines and other structures. Ground instability would cause erosion, affect terrain, slopes, roads, foundations and more. [121]
Svein Tveitdal, Managing Director of the Global Resource Information Database (GRID) in Arendal, Norway, a UNEP environmental information center monitoring the thawing of permafrost, told a meeting at the 21st session of the United Nation's Governing Council in Nairobi, Kenya on February 7, 2001: "Permafrost has acted as a carbon sink, locking away carbon and other greenhouse gases like methane, for thousands of year. But there is now evidence that this is no longer the case, and the permafrost in some areas is starting to give back its carbon. This could accelerate the greenhouse effect." (83)
In a December, 2005 study climate models at National Center for Atmospheric Research (NCAR) show that climate change may thaw the permafrost located in the top 10 feet of permafrost, releasing carbon dioxide into the atmosphere. "People have used models to study permafrost before, but not within a fully interactive climate system model," says NCAR's David Lawrence, the lead author. The coauthor is Andrew Slater of the University of Colorado's National Snow and Ice Data Center. "Thawing permafrost could send considerable amounts of water to the oceans," says Slater, who notes that runoff to the Arctic has increased about 7 percent since the 1930s. According to the NCAR press release (December 19, 2005) permafrost may contain 30% of all the carbon found in soil worldwide. In areas to a depth of 11.2 feet climate models (assuming business as usual scenarios) show permafrost presently in an area of 4,000,000 square miles shrinking to 1,000,000 square miles by 2050 and 400,000 square miles by 2100. With a scenario of low emissions (assuming a high degree use of alternative energy sources and conservation) permafrost is still expected to shrink to 1.5 million miles by 2100.........In a USA Today (December 26, 2005) interview David Lawrence says, "If that much near-surface permafrost thaws, it could release considerable amounts of greenhouse gases into the atmosphere, and that could amplify global warming," ….."We could be underestimating the rate of global temperature increase." In a study reported in the journal Science June 16, 2006 (see San Francisco Chronicle article) researchers say that thawing permafrost may add to the buildup in atmospheric greenhouse gases significantly, stating that present climate models do not include releases of Siberian carbon dioxide from permafrost. Dr. Ted Schuur of the University of Florida traveled to Siberia and secured samples of permafrost soil up to 10 feet in length, maintaining it in a frozen state until arriving back in his laboratory, where the thawing soil was attacked by microbes, releasing carbon dioxide in the process. The frightening scenario that scientists, Sergey A. Zimov of the Russian Academy of Sciences, Ted Schuur and Stuart Chapin III of the University of Alaska, paint is one of hundreds of billions of tons of greenhouse gases entering an already destabilized atmosphere this century, spurring yet more warming in a positive feedback syndrome. Extend this scenario to Alaska, Canada and Scandinavia, where permafrost underlies much of these regions and there's no other way to describe it. We'rTe in trouble.<>

Tundra

A name very suited to the environs of the arctic and subarctic, tundra means 'treeless plain' in Finnish. The tundra is a biome (a major segment of a particular region having distinctive vegetation, animals and microorganisms adapted to a unique climate), home to about 1700 kinds of plants, including shrubs, mosses, grasses, lichens and 400 kinds of flowers. About 50 billion tons of carbon are estimated to be held in a frozen state in the tundra, and now the tundra is beginning to become a source of carbon dioxide. In the 1970's University of California biologist Walter Oechel studied carbon dioxide emissions in the tundra, which until this time had been thought of as a carbon sink. Doing further tests in the 1980's, Oechel discovered that this was no longer the case, that warming temperatures had changed the tundra to a net emitter of carbon dioxide. Says Oechel, " We found to our great surprise that the tundra was already losing carbon dioxide to the atmosphere. So that by the start of these experiments, which was in 1982, the tundra had already warmed and dried enough, that its historic role as a carbon sink had reversed and changed. It was now losing carbon dioxide to the atmosphere. That was totally unexpected."

Top 10 steps to Create Global Warming Awareness

1. Use less produce able Carbon Dioxide bulbs or lightings
Don’t use fluorescent bulbs as it takes high ratio of energy to output large amount of lights. So replace it with less energy consumable light bulbs. Scientist has discovered that if we use CFL bulb than we can lower down nearly 700 pounds of carbon dioxide out of the air over the bulb's lifetime. It use only a quarter of the energy consumed by conventional bulbs.
2. Efficient usage of Home Appliances
In home we are using energy more than required and it resulting wastage of energy. As we get energy by power plants, which burn fossil fuel to power our electric products. Making it burn outputs air pollution and contributes to smog, acid rain and global warming. If we use less energy definitely we will be saving money as well as energy.The American Council for an Energy-Efficient Economy estimates that if each of us increases the energy-efficiency in our major appliances by 10 - 30%, we'll release the demand for electricity by the equivalent of 25 large power plants!
3. Buy power saving Appliances
While you go for shopping for any electric appliances don’t buy appliances which use power above than average use specially appliances such as Refrigerator, Stove, Washer/Dryer, Air Conditioners, Water Heater, Computers and Home Office Equipment. Buy which has highest energy efficiency rating specified by any experts or sources.By using appliances marked with Energy Star Logo can help us to save 15 percent of energy than the federal requirement.Energy Star is the symbol for energy efficiency. It's a label created by the U.S. Environmental Protection Agency and the U.S. Department of Energy to help consumers save money and minimize air pollution.
4. Mineralize the energy needed for heating
USA Scientist concluded that heating and cooling systems in the U.S.A. emit into the atmosphere more than millions of tons of carbon dioxide each year, which increasing the % of Global Warming rates. By decreasing the usage appliances we can save lots of energy which emits heat.
5. Save your fuel while driving
You can’t image that you can manage to save your fuel 30% by simple vehicle maintenance and attention to your style of driving in an appropriate way. You should take care of for saving fuel by: Don’t drive aggressively, Drive steadily at posted speed limits, Avoid idling your vehicle, Make sure your tires are properly inflated, Select the right gear, Service your vehicle regularly and much more.
6. Drive less and Use public transports more
If you try to drive less and walk more than it would be great contribution towards saving energy and creating global warming awareness. You should try travel by taking the bus, riding a bike, or walking. Try consolidating trips to the mall or longer routine drives. Encourage car-pooling.
7. Paint your Home according to Seasons
Paint your home a light color if you live in a warm climate, or a dark color in a cold climate. This can contribute saving up to 5000 pounds of carbon dioxide per year.
8. Recycle every material
Try not to use products and materials which are not recyclable. Recycling saves energy, landfill space and natural resources. Increase usage of recycled materials such as paper & cardboard, plastic, glass, aluminum, steel & copper. Visit your local recycling center and find out what materials they accept for recycling. For your convenience use plastic bags or totes to store materials for recycling.
9. Eat more vegetarian meals than non-vegetarians
Avoid eating non-vegetarian food as it is not good for human health as well as to the planet. Try to this meal to increase your contribution towards Global Warming Awareness: Nutburgers, Irish Colcannon, Tofu Tamale Pie, Tofu Loaf, Grilled Polenta with Portabello Mushrooms, Vegetable Fajitas and many more.
10. Choose clean Energy Options
If you can choose your electricity supplier, pick a company that generates at least half its power from wind, solar energy and other renewable sources.

Smog

The term smog was first used in 1905 by Dr H A Des Voeux to describe the conditions of fog that had soot or smoke in it. Smog is a combination of various gases with water vapour and dust. A large part of the gases that form smog is produced when fuels are burnt. Smog forms when heat and sunlight react with these gases and fine particles in the air. Smog can affect outlying suburbs and rural areas as well as big cities. Its occurrences are often linked to heavy traffic, high temperatures, and calm winds. During the winter, wind speeds are low and cause the smoke and fog to stagnate; hence pollution levels can increase near ground level. This keeps the pollution close to the ground, right where people are breathing. It hampers visibility and harms the environment. Heavy smog is greatly decreases ultraviolet radiation. In fact, in the early part of the 20th century, heavy smog in some parts of Europe resulted in a decrease in the production of natural vitamin D leading to a rise in the cases of rickets. Smog causes a misty haze similar to fog, but very different in composition. In fact the word smog has been coined from a combination of the words fog and smoke. Smog refers to hazy air that causes difficult breathing conditions.
The most harmful components of smog are ground-level ozone and fine airborne particles. Ground-level ozone forms when pollutants released from gasoline and diesel-powered vehicles and oil-based solvents react with heat and sunlight. It is harmful to humans, animals, and plants.
The industrial revolution in the 19th century saw the beginning of air pollution in Europe on a large scale and the presence of smog mainly in Britain. The industries and the households relied heavily on coal for heating and cooking. Due to the burning of coal for heat during the winter months, emissions of smoke and sulphur dioxide were much greater in urban areas than they were during the summer months. Smoke particles trapped in the fog gave it a yellow/black colour and this smog often settled over cities for many days.
The effects of smog on human health were evident, particularly when smog persisted for several days. Many people suffered respiratory problems and increased deaths were recorded, notably those relating to bronchial causes. A haze of dense harmful smog would often cover the city of London. The first smog-related deaths were recorded in London in 1873, when it killed 500 people. In 1880, the toll was 2000. London had one of its worst experiences with smog in December 1892. It lasted for three days and resulted in about 1000 deaths. London became quite notorious for its smog. By the end of the 19th century, many people visited London to see the fog. Despite gradual improvements in air quality during the 20th century, another major smog occurred in London in December 1952. The Great London Smog lasted for five days and resulted in about 4000 more deaths than usual. In response to the Great London Smog, the government passed its first Clean Air Act in 1956, which aimed to control domestic sources of smoke pollution by introducing smokeless zones. In addition, the introduction of cleaner coals led to a reduction in sulphur dioxide pollution. In the 1940s, severe smog began covering the city of Los Angeles in the USA.
Relatively little was done to control any type of pollution or to promote environmental protection until the middle of the 20th century. Today, smoke and sulphur dioxide pollution in cities is much lower than in the past, as a result of legislation to control pollution emissions and cleaner emission technology.

Carbon Footprint

Whenever human activities involve the burning of fossil fuels, carbon dioxide is emitted. This waste will accumulate in the atmosphere, contributing to global climate change, unless it can be captured and stored by plants. The carbon Footprint therefore measures the demand on biocapacity that results from burning fossil fuels in terms of the amount of forest area required to sequester these carbon dioxide emissions. Note that this does not suggest planting forests is the 'solution' to climate change; on the contrary, it shows that the biosphere does not have sufficient capacity to sequester all the carbon we are currently emitting.



Humanity's carbon Footprint has grown much faster than any other Footprint component, increasing more than nine fold since 1961 and now comprising about half the total demand we place on nature's regenerative capacity. With our overall Footprint now exceeding global biocapacity by about 30%, reducing our carbon Footprint is essential if we want to get out of overshoot. To be effective, however, this must be done in a careful, Footprint-neutral manner, and not simply by transfering demand from one Footprint component to another. For example, biofuels can be substituted for fossil fuels, but this requires cropland to grow the necessary biomass. If the resultant decrease of carbon Footprint is more than compensated for by an increase in the cropland Footprint, overshoot will grow rather than shrink.

Recently the term 'carbon Footprint' has been adopted as a shorthand for the amount of carbon (usually in tonnes) being emitted by an organization or activity. The carbon component of the Ecological Footprint differs in that it goes beyond simply describing the physical quantity of carbon being emitted, instead indicating the amount of nature's limited regenerative capacity required to get this carbon back out of the atmosphere.

Ten things you can do to help curb Global Warming

Responsible Choices

The choices we make and the products we buy test our commitment to maintain a healthy planet. When we burn fossil fuels—such as oil, coal, and natural gas—to run our cars and light our homes, we pump carbon dioxide (CO2) into the air. This thickens the heat-trapping blanket that surrounds the planet, causing global warming.
Choosing modern technology can reduce our use of fossil fuels and help protect the planet. These ten steps will help curb global warming, save you money, and create a safer environment for the future.

1.Drive Smart!
A well-tuned car with properly inflated tires burns less gasoline—cutting pollution and saving you money at the pump. If you have two cars, drive the one with better gas mileage whenever possible. Better yet, skip the drive and take public transit, walk, or bicycle when you can.

2.Buy Local and Organic
Did you know the average American meal travels more than 1,500 miles from the farm to your plate? Think of all the energy wasted and pollution added to the atmosphere—not to mention all the pesticides and chemicals used to grow most produce! So go to your local organic farmer to get your fruits and veggies.

3.Support clean, renewable energy.
Renewable energy solutions, such as wind and solar power, can reduce our reliance on coal-burning power plants, the largest source of global warming pollution in the United States. Call your local utility and sign up for renewable energy. If they don't offer it, ask them why not?

4.Replace incandescent light bulbs with compact fluorescent bulbs.
Especially those that burn the longest each day. Compact fluorescents produce the same amount of light as normal bulbs, but use about a quarter of the electricity and last ten times as long. Each switch you make helps clean the air today, curb global warming, and save you money on your electricity bill.

5.Saving energy at home is good for the environment and for your wallet.
Start with caulking and weather-stripping on doorways and windows. Then adjust your thermostat and start saving. For each degree you lower your thermostat in the winter, you can cut your energy bills by three percent. Finally, ask your utility company to do a free energy audit of your home to show you how to save even more money.

6.Become a smart water consumer.
Install low-flow showerheads and faucets and you'll use half the water without decreasing performance. Then turn your hot water heater down to 120°F and see hot-water costs go down by as much as 50 percent.

7.Buy energy-efficient electronics and appliances.
Replacing an old refrigerator or an air conditioner with an energy-efficient model will save you money on your electricity bill and cut global warming pollution. Look for the Energy Star label on new appliances or visit their website at www.energystar.gov to find the most energy-efficient products.

8.Plant a Tree, protect a forest.
Protecting forests is a big step on the road to curbing global warming. Trees "breathe in" carbon dioxide, but slash-and-burn farming practices, intensive livestock production, and logging have destroyed 90 percent of the native forests in the United States. And you can take action in your own backyard—planting shade trees around your house will absorb CO2, and slash your summer air-conditioning bills.

9.Reduce! Reuse! Recycle!
Producing new paper, glass, and metal products from recycled materials saves 70 to 90 percent of the energy and pollution, including CO2, that would result if the product came from virgin materials. Recycling a stack of newspapers only four feet high will save a good-sized tree. Please... buy recycled products!

10.Mount a local campaign against global warming.
Educate your community about how it can cut global warming pollution. Support measures at the national, state, and local level that:

Make automobiles go further on a gallon of gas;
Accelerate the use of clean, renewable energy sources, such as solar and wind;
Increase energy efficiency and conservation; and
Preserve forests around the world.