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 20% 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 2004 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 as
effective 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 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) 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.
Also:
Forests 610 billion tons of Carbon
Soils 1580 " " "
Deep Ocean 38100 " " " Source: U.S.Global Change Research Information Office
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're in trouble.
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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."
Carbon Dioxide Increasing in Atmosphere
The atmospheric levels of the greenhouse gas carbon dioxide, have increased since pre-industrial times from 280 part per million (ppm) to 377.5 ppm (2004 Carbon Dioxide Information Analysis Center), a 34% increase. Carbon dioxide concentrations in the atmosphere are the highest in 650,000 years. Carbon dioxide is a by-product of the burning of fossil fuels, such as gasoline in an automobile or coal in a power plant generating electricity.
Methane Also Increasing
Levels of atmospheric methane, a powerful greenhouse gas, 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. Back to Top of Page
More Frequent Extreme Weather
The year 1999 was the fifth-warmest year on record since the mid-1800's; 1998 being the warmest year. According to Thomas Karl, director of the National Climatic Data Center (NOAA), the current pace of temperature rise is "consistent with a rate of 5.4 to 6.3 degrees Fahrenheit per century." By comparison, the world has warmed by 5 to 9 degrees Fahrenheit since the depths of the last ice age, 18,000 to 20,000 years ago.
The potential for floods and droughts is increasing."....... the heating from increased greenhouse gases enhances the hydrological cycle and increases the risk for stronger, longer-lasting or more intense droughts, and heavier rainfall events and flooding, even if these phenomena occur for natural reasons. Evidence, although circumstantial, is widespread across the United States. Examples include the intense drought in the central southern U.S in 1996, Midwest flooding in spring of 1995 and extensive flooding throughout the Mississippi Basin in 1993 even as drought occurred in the Carolinas, extreme flood events in winters of 1992-93 and 1994-95 in California but droughts in other years (e.g, 1986-87 and 1987-88 winters)," says Dr. Kevin Trenberth of the National Oceanic and Atmospheric Administration (NOAA). [6] Back to Top of Page
Disappearing Glaciers Ice is melting all over the planet. Glaciers are melting on six continents.
If present warming trends continue, all glaciers in Glacier National Park could be gone by 2030. [54] The park's Grinnell Glacier is already 90% gone. Pictured here is the glacier prior to its meltdown. [120]
Because of global warming, the glaciers of the Ruwenzori range in Uganda are in massive retreat.
The Bering Glacier, North America's largest glacier, has lost 7 miles of its length, while losing 20-25% of parts of the glacier.
Ice cores taken from the Dunde Ice Cap in the Qilian Mountains on the northeastern margin of the Qinghai-Tibetan Plateau indicate that the years since 1938 have been the warmest in the last 12,000 years.
The melting is accelerating. The Lewis Glacier on Mt. Kenya (In Kenya) has lost 40% of its mass during the period 1963-1987 or at a much faster clip than during 1899-1963. [29]
See Gary Braasch's Pictures of Receding Glaciers
See More Images of Receding Glaciers
Ohio State University researcher Lonnie Thompson on global warming and retreating glaciers
In southern Peru the rate of melting of the Qori Kalis glacier during the 8 year period 1983 to 1991 was 3 times the pace of the previous 20 years, 1963 to 1983. "By the time we probably know what they are doing, it will be far too late to worry about it because they are going to be like galloping glaciers," says Ellen Mosley Thompson, climate expert at Ohio State University. [30] The Qori Kalis is receding at about two feet per day. Sitting beside the glacier, one could witness the melting hour by hour. [120]
In a study that appeared in the journal, Science, September 15, 2000, a team led by Lonnie G. Thompson, including Ellen Mosley-Thompson, both of Ohio State, analyzed ice cores that came from deep within a glacier more than 20,000 feet high in the Himalayas. The results of their research showed that the past 100 years have been the hottest period in 1,000 years high in the Himalayas. Also their research supports other studies that demonstrated a dramatic decline in water levels of glacier-fed rivers, and that the high elevations are warming much more than the global average (one degree F). Mosley-Thompson says, "For these rivers to continue to flow year-round, they have to be fed by ice in the high mountains. The question then is where will the river flow come from during the dry season?" [59]
Greenland's glaciers are moving more rapidly to the sea, caused, perhaps, by melt water lubricating the base of the glaciers. See below for another look at dwindling ice mass in Greenland.
The Tasman Glacier in New Zealand has thinned by more than 100 meters in the past century. Glaciers in New Zealand have shrunk about 26% between 1890 and 1998. [54]
The melting of the Gangotri Glacier in India is accelerating with an average rate of retreat of 30 meters annually. The rate between 1935 and 1990 was 18 meters per year and 7 meters annually between 1842 and 1935. [54]
A glacier from which Sir Edmund Hillary and Tenzing Norgay set out to conquer Mount Everest nearly 50 years ago has retreated three miles up the mountain due to global warming. The head of the Nepal Mountaineering Association, Tashi Jangbu Sherpa, says " that Hillary and Tenzing would now have to walk two hours to find the edge of the glacier which was close to their original base camp." [114]
Portage Glacier in the Chugach National Forest, south of Anchorage, is another casualty of climate change, say scientists at the University of Alaska Fairbanks. These researchers found that melting glaciers are responsible for at least 9 percent of the global sea-level rise over the past century.
Back to Top of Page
Melting Arctic Sea Ice
The Arctic, with an area about the size of the United States, is seeing average temperatures similar to the Antarctic, almost 5 degrees Fahrenheit warmer than the planet as a whole
Arctic sea ice has shrunk by 250 million acres -- an area the size of California, Maryland and Texas combined.
In a N.Y Times article (Nov. 17, 1999) it was reported that scientists have discovered that from 1993 through 1997 average Arctic sea ice thickness was six feet. This represents a significant reduction in Arctic sea ice from 1958 through 1976 when average thickness measured 10 feet. This means that in less than 30 years, there has been a 40% loss of arctic sea ice. In a Washington Post article (Dec. 3, 1999) it was noted that in the Arctic, sea ice is shrinking at a rate of 14,000 square miles annually, an area larger than Maryland and Delaware combined.
According to a report by Norwegian scientists, the arctic sea ice in about 50 years could disappear entirely each summer. Researchers at the Nansen Environmental and Remote Sensing Center based their predictions on satellite pictures. These pictures showed that the Arctic winter icescapes decreased by 6% (a Texas-size area) during the last 20 years. [61] Back to Top of Page
Melting Antarctic Sea Ice
The Antarctic Peninsula has seen an increase in average temperatures of almost 5 degrees Fahrenheit in the last 50 years. Heavy sea ice has been the norm in the Antarctic, but in the 1990's sea ice disintegration has begun, notes Robin Ross, a biological oceanographer with the University of California at Santa Barbara. During the year 1998, the Antarctic displayed a record low in winter sea ice. Back to Top of Page
Greenland's Ice Sheet Melting
In a recent study by researchers from NASA's Goddard Space Flight Center shows that Greenland's ice sheet, about 8% of the Earth's grounded ice (Antarctica possessing 91% of land ice), is losing ice mass. A NASA high-tech aerial survey shows that more than 11 cubic miles of ice is melting along Greenland's coasts yearly, accounting for 7% of the annual global sea level rise. Measurements over the last century suggest that sea level has risen 9 inches, enough to cause flooding in low-lying areas, when a storm occurs. Sea level increase could worsen, if the present trend continues, says William Krabill, lead author of the NASA study. [53] Back to Top of Page
Tropical Diseases Spreading
A recent study by New Zealand doctors, researchers at the Wellington School of Medicine's public health department said outbreaks o f dengue fever in South Pacific islands are directly related to global warming. [9] Global warming is projected to significantly increase the range conducive to the transmission of both dengue and yellow fevers. [10] Back to Top of Page
Oceans Warming With Coral Bleaching & Disintegration
Devastating loss of coral in the Caribbean - March, 2006
In March, 2006 researchers discovered devastating loss of coral in the Caribbean off Puerto Rico and the Virgin Islands. "It's an unprecedented die-off," said National Park Service fisheries biologist Jeff Miller, who last week checked 40 official monitoring stations in the Virgin Islands. "The mortality that we're seeing now is of the extremely slow-growing reef-building corals. These are corals that are the foundation of the reef ... We're talking colonies that were here when Columbus came by have died in the past three to four months."...............Miller noted that some of the devastated coral can never be replaced because it only grows the width of one dime each year.
If coral reefs die "you lose the goose with golden eggs" that are key parts of small island economies, said Edwin Hernandez-Delgado, a University of Puerto Rico biology researcher. While investigating the widespread loss of Caribbean coral, Hernandez-Delgado found a colony of 800-year-old star coral — more than 13 feet high — that had just died in the waters off Puerto Rico.........."We did lose entire colonies," he said. "This is something we have never seen before."
"We haven't seen an event of this magnitude in the Caribbean before," said Mark Eakin, coordinator of the National Oceanic and Atmospheric Administration's Coral Reef Watch.
Tom Goreau of the Global Coral Reef Alliance says that compared to coral areas in the Indian and Pacific ocean, where warming waters have brought about a 90% mortality rate, the Caribbean is healthier.
The Caribbean is actually better off than areas of the Indian and Pacific ocean where mortality rates — mostly from warming waters — have been in the 90 percent range in past years, said Tom Goreau of the Global Coral Reef Alliance. Goreau called what's happening worldwide "an underwater holocaust."
"The prognosis is not good," said biochemistry professor M. James Crabbe of the University of Luton near London. "If you want to see a coral reef, go now, because they just won't survive in their current state."