The term "global warming" refers to an increase in Earth's mean global temperature because a part of Earth's outgoing infrared radiation is retained by several trace gases in the atmosphere whose concentrations have been increasing because of human industrial, commercial, and agricultural activities. These gases have the ability to absorb radiation, leading to the tendency of the atmosphere to create warmer climates than would otherwise be the case. The most important naturally occurring trace gases that have the ability to absorb infrared radiation are water vapor (H2O), carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), and ozone (O3). In addition, there are some industrial gases that are extremely effective absorbers of the radiation. Important among these are chlorofluorocarbons (CFCs), perfluorocarbons, hydrochlorofluorocarbons, hydrofluorocarbons (HFCs), and sulfur hexafluoride (SF6). These gases are analogous to the glass in a greenhouse, which also leads to the net trapping of infrared radiation, hence the terms "greenhouse gases" (GHGs) and "greenhouse effect." These GHGs act as a partial blanket for the thermal radiation from the surface and make the atmosphere warmer than it would otherwise be. Before human intervention, Earth's radiation balance was in equilibrium, resulting in a mean average temperature of Earth at 15°C (59°F). Without the presence of naturally occurring GHGs, Earth's average surface temperature would have been −18°C (−0.4°F). This difference of 33°C (91.4°F) is due to the natural greenhouse effect, which has made Earth a habitable planet. Although the level of naturally occurring GHGs may change naturally over time, their concentration has steadily increased since the Industrial Revolution that began around 1750, because of fossil fuel combustion, deforestation, biomass burning, drainage of wetlands, conversion of natural into agricultural ecosystems, and plowing/cultivation of soil.

The concentration of CO2 has increased from about 280 parts per million by volume (ppmv) in the preindustrial era to about 370 ppm in 2000, and is increasing at the rate of about 1.5 ppm/yr (0.4 percent/yr). The atmospheric concentration of CH4 has increased from 700 parts per billion by volume (ppbv) to 1,720 ppbv, and is increasing at the rate of 10 ppbv/yr (0.6 percent/yr). Similarly, the concentration of N2O has increased from 275 ppbv to 312 ppbv and is increasing at the rate of about 0.8 ppbv/yr (0.25 percent/yr) (Bruce, Lee, and Haites 1996). Because of the successful implementation of the Montreal Protocol in 1987, the concentration of industrial gases has been decreasing.

There are three anthropogenic human-derived sources of atmospheric enrichment of CO2: (1) fossil fuel combustion; (2) cement manufacturing; and (3) land use change involving deforestation, biomass burning, and cultivation. Fossil fuel combustion annually emits 6.22 Pg C (1 Pg = 1 billion metric tons) as CO2, 46 to 155 Tg of C (1 Tg = 1 million metric tons) as CH4, and 0.7 to 1.8 Tg N as N2O and NOx. The fossil fuel emission has steadily increased over the last 150 years. The CO2-C emission from fossil fuel combustion was negligible in 1850, 1,850 Tg/yr in 1900, 1.7 Pg/yr in 1950, and 6.2 Pg/yr in 1995 (Hansen, et al. 1998, pp. 12753–12758). Cement manufacturing emits 0.2 Pg C/yr as CO2. Tropical deforestation and soil cultivation annually emit 0.6 to 2.6 Pg C as CO2, 160 to 460 Tg of C as CH4, and 2.2 to 6.8 Tg N as NOx (Harvey 2000, pp. 16–20). From 1850 to 1998, approximately 270 (±30) Pg C has been emitted as CO2 by fossil fuel combustion and cement production. During the same time, about 136 (±55) Pg has been emitted as a result of deforestation and land use change, of which 78 (±17 Pg) is due to depletion of the soil organic carbon pool (Watson, et al. 2000, p. 4; Lal 1999, p. 317).

The alteration in Earth's radiation budget because of an increase in atmospheric concentration of GHGs is referred to as "radiative forcing," and is measured in w/m2. The radiative forcing of three gases (CO2, CH4, and N2O) since the preindustrial era is 2.45 w/m2, due to the accelerated greenhouse effect or global warming. The GHGs differ with regard to their radiative forcing and their life span, or residence time in the atmosphere. This relative ability of GHGs is called the global warming potential or GWP. The GWP is computed relative to CO2, and is 1 for CO2, 21 for CH4, 210 for N2O, 1,800 for O3, and 4,000 to 12,000 for CFCs. It is estimated that the mean global temperature has increased by about 0.5°C (32.9°F) since the preindustrial era. With business as usual, the radiation budget of Earth may change within a short span of several decades to a century, with an attendant increase in Earth's mean temperature of 1 to 4°C (33.8 to 39.2°F). The projected increase will be less in the tropics than in the boreal, temperate, and cold regions. The greenhouse effect is tolerable (i.e., the biomes or ecological communities comprising plants and animals can adapt) if the rate of increase in Earth's mean temperature is about 0.1°C (32.18°F) per decade.

World soils constitute the third largest global C pool (after oceanic and geologic), and comprise 1,550 Pg of soil organic carbon (SOC) and 750 Pg of soil inorganic carbon (SIC). Thus, the soil C pool is 3.2 times the atmospheric pool (720 Pg), and 4.1 times the biotic pool (560 Pg). The C depleted from the SOC pool can be resequestered through adoption of appropriate land use and soil/crop/vegetation management practices (Lal and Bruce 1999, p. 182; Lal 2001a, pp. 171–172). Restoration of degraded soils and ecosystems and desertification control have a potential to sequester C in soil and the biota and to decrease the rate of enrichment of GHGs in the atmosphere (Lal 2001b, p. 52; 2001c, p. 23).

There are short-term and long-term strategies of mitigating the accelerated greenhouse effect. In the short term, it is important to improve energy use efficiency and to identify strategies of CO2 sequestration. In the long term, it is important to develop noncarbon fuel sources. Carbon sequestration in soil and vegetation through restoration of degraded soils and the ecosystem and adoption of appropriate land uses is a winning strategy.

Thanks for posting this.

I think most of us already know all of this, and the problem is not the lack of knowledge, but the lack of initiative to do something about it.

Or, we do try to do our part, but half-heartedly.

One thing I'd love to see is builders building smaller houses that are much more energy-efficient (think solar panels and grey water recycling systems and such), but less expensive than the large cookie-cutter homes you see today. Of course, that will probably never happen because energy companies want money from us, despite advertising how they want to help us save money.

My husband and I are currently renting... we'd love to someday purchase a new house that's less than 1000 sq ft, but new houses simply don't come in such a size. Sure, one could purchase land and build your own customized house, but we can't afford it (it'd cost just as much if not more than the big new cookie-cutter houses on the market).

"Global Warming" as a theory is based on computer modelling that demonstrates that Earth's average temperature is rising. Warming and cooling is generally caused naturally by cyclical changes in nature.

"Global Warming" as a cause, hypothesized (although presented in appearrance as fact) by the opening post, holds that natural cyclical changes in climate are being caused by man. This mindset is so vain and narcissitic that it is barely credible. The average temperature in the United States, for instance, has been falling, not rising. That doesn't exactly square with the models, does it? The warmest temperatures in the United States, as example, were recorded in the 1930s when there were far less cars on the road than there are now. Many glaciers around the world are growing, not shrinking and, here's a surprise, they grow and shrink [u]naturally[/u] and man has nothing to do with it.

The Anthropogenic Global Warming hysteria that is sweeping our planet (doubtlessly the genesis of the opening post) is a hoax, no matter how many studies and citations it is cloaked in. It is a grand design to transfer wealth and poltical power even when it is not necessary to do so. None of the studies predicting a climactic doomsday yet properly stood up to scientific scrutiny.

You might remember, after all, the hysteria in the 1970's of a coming Ice Age caused by man. I'm still waiting for that. Then there was the Ozone Hole scare of the 1980's... now fully disproved as a complete hoax. The current Global Warming hysteria is simply the next step down that trail.

CO2 problem? Plant a couple of trees. CO2 is a fertilizer for all green plants. They can't live without it. Heard of photosynthesis? And the current measurable CO2 levels are considerably lower than measurements recorded in fossil and soil samples from earlier times. And what [u]exactly[/u] is "adoption of appropriate land uses"? What kind of agrarian reform is that?

The short and long term strategies of the AGW crowd are to control people's behaviors and enrich themselves by selling new technologies and scams like "carbon credits" (see Al Gore's stock portfolio while considering the hundreds of tons of "greenhouse gases" he pumps into the environment travelling in his Gulfstream V). But because it's a cause with some star power and cachet, and it's being drumbeated by even the corporate likes of PG&E (tell me there isn't something fishy in that), it's gained traction and it consumes far more thought and treasure than it really deserves.

Everyone is entitled to their opinions, but there seems to be a growing segment that thinks the "global warming" scare is exactly that.

To believe that mankind has not caused any damage to the environment is incredibly short-sighted and narrow-minded (no offence, but it is).

I agree that temperature changes are cyclical regardless of human activity, but what exactly is the point of debating about the stats? To shrug off our responsibilities to live a sustainable lifestyle on this planet?

There is no denying that animals and plants are becoming extinct each day... sure, it might not be because of glaciers growing/shrinking, but natural diversity is decreasing, and it is becauase humankind as a whole is destroying habitats.

Yes, "global warming" may (or may not) be a scare tactic to get people to become more environmentally conscious, but I don't understand what's so wrong with treading a bit lighter on this earth.

I completely agree with taking all stats and news reports with a grain of salt, but at the same time, actions speak louder than words, so please just treat our world a little bit better.

Let's go point by point.

quote:

Originally posted by echomyst:
To believe that mankind has not caused any damage to the environment is incredibly short-sighted and narrow-minded (no offence, but it is).

And no offense but to simply assume man is the root of all ills. as the AGW hysteria crowd would have us believe, is vain and self centered to the point of being delusional. Normal volcanic activity puts more gunk and gases in the air than man does.

But let's bring it closer to home. California's air quality is better than it was in the 1960's and 70's when there were millions less people. By contrast, have you been watching any of the Olympic coverage? Have you seen the Beijing skyline? If the answer is "yes" then you aren't watching as it is nearly invisible thanks to the massive pollution.

But since China is specifically exempted from Hyoto and other worldwide pollution standards I guess it's okay.

quote:

I agree that temperature changes are cyclical regardless of human activity, but what exactly is the point of debating about the stats? To shrug off our responsibilities to live a sustainable lifestyle on this planet?

Then what is the point of the "sustainable lifestyle" if, as you seem to admit, the temperatures will rise and fall regardless of what we do?

quote:

There is no denying that animals and plants are becoming extinct each day...

And they've been going extinct since the dawn of time just as sure as the rising and setting of the sun. Nature does that, you know, and was doing it long before man had an influence of any kind.

quote:

sure, it might not be because of glaciers growing/shrinking, but natural diversity is decreasing, and it is becauase humankind as a whole is destroying habitats.

Really? Where specifically? It might surprise you but more land is vacant and untouched by man on this planet than is settled and lived upon.

quote:

Yes, "global warming" may (or may not) be a scare tactic to get people to become more environmentally conscious, but I don't understand what's so wrong with treading a bit lighter on this earth.

There is nothing wrong with treading a bit lighter. What is wrong is the massive redistribution of wealth and political power the socialistic AGW hysteria crowd are driving with their line of bilge. And the economic impacts as all of us Americans (you know, the eeeeee-vil Americans) are being forced toward a Luddite world while the "emerging economies" work and pollute overtime to try and catch up to us.

A grain of salt... more like twenty pound licks, if you ask me.

I completely agree with taking all stats and news reports with a grain of salt, but at the same time, actions speak louder than words, so please just treat our world a little bit better.[/QUOTE]

Hey Big Dog, how I've missed you!
(you know I can't keep out of this for too long!)

Let's go point by point:

"vain and self centered human":

This is not a black and white issue. No one has claimed that humans are the sole root of all our environmental ills...you said it yourself it ain't simple..

"Beijing"

Big Dog wrote:
"But since China is specifically exempted from Hyoto and other worldwide pollution standards I guess it's okay."


Um, it's Kyoto,not "Hyoto", and when you pee in the pool does the pee just stay right there with you?
No Sir, it dissipates in the pool water much like lots and lots of pollution from all over the place (Kyoto exemption or not) that travels globally...

"sustainable lifestyle"

temps will rise and fall sure, but must we help it swing further and further, or do we try to mitigate it? Or at least consider changing our gluttony? Sometimes it's the thought that counts!
You're an all or nothin' kinda guy aren't cha?


"the cycle of nature"

no one is arguing that it doesn't exist, gee whiz we're not talking Creationism versus Darwinism here...

multiple factors create an inhospitable host planet, Mother Nature and we wacky industrialized nations all sorta work together on this, however to our mutual demise...

Big Dog writes:
"It might surprise you but more land is vacant and untouched by man on this planet than is settled and lived upon"

Now where oh where did you get that nifty little nugget of suggestion?


Current estimates of wilderness

According to a major study, Wilderness: Earth's Last Wild Places, carried out by Conservation International, 46% of the world's land mass is wilderness. For purposes of this report, "wilderness" was defined as an area that "has 70 percent or more of its original vegetation intact, covers at least 10,000 square kilometers (3,861 square miles) and must have fewer than five people per square kilometer."[7] However, an IUCN/UNEP report published in 2003, found that only 10.9% of the world's land mass is currently a Category 1 Protected Area, that is, either a strict nature reserve (5.5%) or protected wilderness (5.4%). [8] Such areas remain relatively untouched by humans. Of course, there are large tracts of lands in National Parks and other protected areas that would also qualify as wilderness. However, many protected areas have some degree of human modification or activity, so a definitive estimate of true wilderness is difficult.

The Wildlife Conservation Society generated a human footprint using a number of indicators, the absence of which indicate wildness: human population density, human access via roads and rivers, human infrastructure for agriculture and settlements and the presence of industrial power (lights visible from space). The society estimates that 26 percent of the earth's land mass falls into the category of "Last of the wild." The wildest regions of the world include the tundra, the taiga, the Amazonian rain forest, the Tibetan Plateau, the Australian outback and deserts such as the Sahara, and the Gobi.[9]

It should be noted that the percentage of land area designated "wilderness" does not reflect "quality" of remaining wilderness, part of which is barren areas with low biodiversity. Of the last natural wilderness areas, the taiga — which is mostly wilderness — represents 11 percent of the total land mass in the Northern Hemisphere.[10] Tropical rainforest represent a further 7 percent of the world's land base.[11] Estimates of the earth's remaining wilderness underscore the rate at which these lands are being developed, with dramatic declines in biodiversity as a consequence.


Ah facts are fun aren't they?

Oh yeah and here's some science for ya:
from those hysterics over at National Geographic:

Q&A

The Ice Man

Stationed atop the world's highest glaciers, paleoclimatologist (and self-taught mountaineer) Lonnie Thompson is unlocking the truth about global warming—one ice core at a time.
By Maren Dougherty



FROZEN ASSETS: Lonnie Thompson in his lab's "clean room," May 2004. His collection includes four miles [6.4 kilometers] of rare ice cores.

Lonnie Thompson has spent a collective 840 days above 18,000 feet (5,486 meters)—that's more time at altitude than any Sherpa or mountaineer on the planet. In 27 years he's explored ice fields and glaciers on five continents, reaching destinations as high as 23,500 feet (7,163 meters) on the Dasuopu ice field in the Chinese Himalaya as part of a quest to unlock the Earth's climactic past and look into the future. For the August issue of Adventure, writer Lolly Merrell joined Thompson for a drill on Alaska's Bona-Churchill glacier to retrieve a 1,500-foot (457-meter) ice core, the longest to date.



On Mount Sajama, Bolivia.

Thompson began analyzing ice cores for the information they held about the Earth's historic weather patterns in his lab at Ohio State University, where he's a professor of geological sciences. Figuring that the highest, coldest ice contains the most accurate records, he pioneered new technologies to drill at altitudes such as Peru's treacherously high Quelccaya ice cap. In 2000, Thompson took ice samples from the easiest of the Seven Summits, Mount Kilimanjaro, a peak that has lost 80 percent of its ice cover in the past 100 years. Next summer, he and his crew will take their six tons of equipment to begin research in southwestern Himalaya.

For Thompson, high science has attracted a lot of attention. His projects highlighting radical climate changes have been referenced by Al Gore, the New York Times, and the BBC. Three years ago, Time magazine ranked him as one of "America's Best" in science and medicine.

Here we ask Thompson about his ice-obsessed life and find out what's at stake with the planet's shrinking glaciers.

In the Roland Emmerich film The Day After Tomorrow, abrupt global warming causes mega-tornadoes, hail the size of baseballs, and tsunamis that wipe out entire cities. To what extent is this an exaggeration?

I've seen the movie twice. As far as showing all the climate changes happening at once, it's definitely over the top. But at least it forces the American public to think about climate.

In the real world, where we have detailed climate records—particularly those coming from the ice cores—we know that the climate system is capable of very abrupt changes and that we should be extremely sensitive to the fact that the present system can change dramatically, even if not all at once like in the movie.

You've predicted that the Kilimanjaro ice peak could be gone within 15 years. What's at stake if the glaciers disappear?

Tourism to Kilimanjaro is the number one foreign currency earner for Tanzania. Some 20,000 tourists travel to the mountain each year and half of them make it to the summit, at least partially to see the tropical glaciers that have been immortalized by [visual] artists and in Hemmingway's The Snows of Kilimanjaro. How many people will still travel to the mountain if the glaciers are gone?

I don't think anyone really knows the answer to that—but we may find out sooner than we thought.

I actually believe the glaciers could be gone before 2020, mainly because in the past the ice lost most of its mass from sublimation—the process of changing from a solid to a gas. Sublimation actually requires about seven and a half times as much energy as melting the ice requires. Yet we have photos from the summit of Kilimanjaro taken last summer that indicate that the ice is melting on Furtwängler Glacier at the summit of Kilimanjaro due to increasing temperatures and solar radiation-induced melting. Even with all the tourists who visit the mountain, no one has documented this before.

Disputes are common in the academic community, and global warming has been a hot topic. Do you deal with a lot of resistance?

Global warming is not as controversial as some people would like you to think. The people who actually study global warming agree that the climate is changing, partially due to human activity on the planet. When you consider the evidence, global warming is not something you necessarily have to go out and try to sell, even to critics.

What we do as scientists is look at what is and what has been. If you get the science right, the system plays out and it's just a matter of time before everyone will realize that we do have to do something about this if we want to maintain the type of civilization we live in.

Since global warming is a reality, why aren't people doing more about it?

Whether or not people do something about global warming is more of a human nature issue than a political issue. If you look at human behavior, we tend to deal better with crises than to proactively change before the situation escalates to an emergency. But if there's no choice, humans are capable of huge changes.

Here in Ohio we have the Cuyahoga River that everyone knew was polluted, but it wasn't until it caught on fire that people realized, "Hey, this is a crisis, and we probably ought to do something about it." Now the river's been cleaned-up so that even walleye, pike, and game fish can live in it. It wasn't that we couldn't take care of the problem sooner, it was that we didn't have to do it sooner.

With global warming, we're not quite to the point where the general population's lifestyle is about to be altered.


Once you've drilled and transported the ice cores, do you store them somewhere?

Over the past 20 years we have built a 2,100-square-foot (195-square-meter) storage facility at Ohio State. We have two storage rooms at between -30°C and -35°C, and about 7,000 meters (22,966 feet) of core are stored there. Each room has an alarm system built into it, so if the temperatures go outside of the five degree range, an alarm goes off. We have people at the OSU Environmental Control Center who monitor all the environmentally sensitive facilities on campus 24 hours a day.

Why is storing the ice so important?
The thing that's very clear to us—and we didn't realize this in the beginning—is that we need to keep an archive of ice like that of Kilimanjaro. We do it for other groups to sample and for the future, because it's clear that in as few as 15 years you will not be able to go out into the real world to recover that record. We know that our science and technology will increase, but we need samples to study.

Glaciers serve as the canaries in the coal mine. I grew up in West Virginia, where coal mining was an important part of the state's economy. Coal miners would take canaries down in a cage. If the canary died, they would get out of the mine because it meant methane gas was building up in the system. These tropical glaciers are an early warning system for the climate of the Earth. We need to record the past, then preserve that record for the future, so we can understand what's happening.



What is one of the most important lessons you've learned?
After having worked in some 15 countries around the world, we understand that we live in a world that is interconnected. We all need to make an effort to understand the cultures of the world, because what one group does affects the others. We all can work together to accomplish a mission under very difficult circumstances, and this is something we really need to do in the 21st century.



Related Web Sites

News from National Geographic
Worldwatch Institute researcher says the ice age in The Day After Tomorrow is impossible. Check out why.

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