Introduction

The phrase global warming refers to the documented historical warming of the Earth's surface based upon worldwide temperature records that have been maintained by humans since the 1880s. The term global warming is often used synonymously with the term climate change, but the two terms have distinct meanings. Global warming is the combined result of anthropogenic (human-caused) emissions of greenhouse gases and changes in solar irradiance, while climate change refers to any change in the state of the climate that can be identified by changes in the average and/or the variability of its properties (e.g., temperature, precipitation), and that persists for an extended period, typically decades or longer.

Global Mean Temperature over Land and Ocean (Jan-Dec).

According to the World Meteorological Organization (WMO), the decade of 1998-2007 is the warmest on record. The global mean surface temperature for 2007 is currently estimated at 0.41°C/0.74°F above the 1961-1990 annual average of 14.00°C/57.20°F. WMO states that among other remarkable global climatic events recorded in 2007, a record-low Arctic sea ice extent was observed which led to first recorded opening of the Canadian Northwest Passage.

The NCDC's Preliminary Annual Report on the Climate of 2007 states that:

• "the global annual temperature for combined land and ocean surfaces for 2007 is expected to be near 58.0°F and would be the fifth warmest since records began in 1880," and that
• "the year 2007 is on pace to become one of the 10 warmest years for the contiguous U.S., since national records began in 1895."

Global in Situ Temperature Anomalies and Trends, Surface and Mid Troposphere (Jan-Dec).

On 2 February 2007, the Intergovernmental Panel on Climate Change (IPCC) released the Summary For Policymakers (SPM), an executive summary of the first volume of its 4th Assessment Report entitled, "The Physical Science Basis of Climate Change." The IPCC Report documents that not only do the records show a warming trend during the past half century in land-based temperature data but also in global ocean temperature measurements. The increases in ocean temperatures indicate global warming trends are not an artifact of urbanization or the so-called "heat-island" effect.

Causes of Global Warming

Almost 100% of the observed temperature increase over the last 50 years has been due to the increase in the atmosphere of greenhouse gas concentrations like water vapor, carbon dioxide (CO₂), methane and ozone. Greenhouse gases are those gases that contribute to the greenhouse effect. The largest contributing source of green Greenhouse gases in the atmosphere act like a mirror and reflect back to the Earth a part of the heat radiation, which would otherwise be lost to space. The higher the concentration of green house gases like carbon dioxide in the atmosphere, the more heat energy is being reflected back to the Earth. The emission of carbon dioxide into the environment mainly from burning of fossil fuels (oil, gas, petrol, kerosene, etc.) has been increased dramatically over the past 50 years.

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 come 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 too 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 and most powerful 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 it’s 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 colorless, non-flammable gas with a sweetish odor, commonly known as "laughing gas", and sometimes used as an anesthetic. Nitrous oxide is naturally produced by oceans and rainforests. Man-made sources of nitrous oxide include nylon and nitric acid production, the use of fertilizers 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 carbon 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.

From which sectors do the major greenhouse gas emissions come from? The lower part of the picture shows the sources individually for the gases carbon dioxide, methane and nitrous oxide, respectively 

Effects of Global warming include:

Deaths Due to Climate Change
A study, by scientists at the World Health Organization (WHO) determined that 154,000people die every year from the effects of global warming, from malaria to malnutrition, children in developing nations seemingly the most vulnerable. These numbers could almost double by 2020.

"We estimate that climate change may already be causing in the region of 154,000 deaths...a year," Professor Andrew Haines of the London School of Hygiene and Tropical Medicine told a climate change conference in Moscow. Haines said the study suggested climate change could "bring some health benefits, such as lower cold-related mortality and greater crop yields in temperate zones, but these will be greatly outweighed by increased rates of other diseases." Haines mentioned that small shifts in temperatures, for instance, could extend the range of mosquitoes that spread malaria. Water supplies could be contaminated by floods, for instance, which could also wash away crops

Increasing Storms and Floods
Dr. Thomas Karl, director of the National Climatic Data Center (NOAA), says that global warming has produced an increase in precipitation during the 20th century, mostly in the form of heavy rainstorms, little in moderate, beneficial rainstorms. Thomas Karl also reports that recent decades have produced a 20% increase in blizzards and heavy rainstorms in the U.S. "Hundred-year events are become more frequent now," notes Karl. In a report issued in November, 1999 the Britain's Meteorological Office warned that flooding in Asia and Southeast Asia would increase more than nine fold over the coming decades. Floods are already increasing worldwide. The year 1998 was the worst on record, with 96 floods in 55 countries.

Scientists are saying that global warming is causing early snowmelts. During the month of December 1996 and the first week of January 1997 unusually warm weather caused an early snowmelt that resulted in record flooding in parts of Washington, Oregon, Idaho, California, Nevada and Montana. These floods forced about 500,000 people to leave their homes. In California alone state officials estimated flood damage to homes and businesses at $1.6 billion.

Weather-Related Natural Disasters
On November 28, 1998 the San Francisco Chronicle ran an Associated Press article reporting that dollar damages from weather-related natural disasters (floods, storms, droughts, and fires) worldwide for 1998 totaled $89 billion. (The final figure for 1998 was to be $93 billion.) Total damages for the entire decade of the 1980's were $83 billion (this is the inflation-adjusted figure; actual figure was $54 billion). Damage totals for the 1990's soared above $340 billion, a 300% increase over the 1980's.

Killer Heat Waves
In June, 2003, 1700 people died during a heat wave that hit India, while 35,000 Europeans died in a heat wave the following August.

In July, 1999 more than 250 people died from an unrelenting heat wave that seared the eastern U.S.  Temperatures climbed above 110 degrees Fahrenheit across the Midwest, with Chicago recording a record 119 degrees.

It was July, 1995 when more than 1000 people died from heat-related causes in a heat wave in the Midwest, over 700 of whom died in Chicago, 85 died in Milwaukee.

"High temperatures are likely to become more extreme, and because night temperatures will increase by at least as much as daytime temperatures, heat waves will become more serious," says Dr. Thomas Karl, at the National Climatic Data Center. [5]  

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 Some References to News Sources May Have Lost Link

Islands are Endangered by Rising Seas

·         An article in the fall, 1996 issue of the Earth Island Journal reported that rising seas are about to inundate Pate and Daub, two small islands near the Indian Ocean resort island of Lamu. Kenya has announced plans to spend $517,000 to build walls shielding these islands from the rising surf.

·         In June, 1997, Jacob Nena, president of Micronesia said some of his country's smaller atolls have been abandoned due to rising seas. In addition to rising sea levels, the highly populated atoll of Nuduoro has been victimized by floods due to increasing storm activity, a symptom of global warming.

·         The Maldives environmental minister, Abdul Rasheed Hussain, said that his country's tourism industry is threatened by constant erosion of its beaches. Noted in the San Francisco Chronicle (June 25, 1997).

·         Government officials of the islands, Antigua and Bermuda, in the Caribbean, are convinced that global warming is the cause of a number of recent hurricanes including a 1994 storm that wiped out virtually the entire economy. Noted in San Francisco Chronicle article of February 11, 1997.

·         The island state of Kiribati (population, 75,000) is being threatened with rising seas, engulfing homes and crops. These are rising sea levels, surges during sunny weather. Says one islander, "It's nice weather, and all of a sudden water is pouring into your living room."

·         Majuro, the capital of the Marshall Islands, where islets are in some places only as wide as the two-lane road that traverses each of them, a single wave often sprays the country from coast to coast. The cost of protecting the capital alone with a seawall would be insurmountable, costing up to three times the total national economic output.

·         In November, 2000 Teleke P. Lauti, assistant minister of natural resources and environment of Tuvalu, traveled to The Hague, Netherlands to plead to those negotiating the final draft of the Kyoto Protocol. Tuvalu is an island state, comprising a number of low-lying islands, altogether about 1/7th the size of Washington D.C.and located directly west of Australia and north of New Zealand. He told negotiators that his country faces the threat of storm surges that wash directly across the entire island. It is happening now. As the fate of Tuvalu and its 10,000 inhabitants seems hopeless against the encroaching waters, the government of Tuvalu is weighing whether or not to purchase land in another country. Mr. Lauti says, "When a cyclone hits us, there is no place to escape. We cannot climb any mountains or move away to take refuge. It is hard to describe the effects of a cyclonic storm surge when it washes right across our islands. I would not want to wish this experience anyone."  Among the small islands of Tuvalu, rising seas have already endangered sacred sites. Rising seas have seeped into some islands' croplands, making it too salty to grow vegetables. Tuvalu farmers are now beginning to grow their taro crops not in traditional pits, but in tin containers filled with compost. Whose responsible for the needs of future climate change refugees, such as Tuvalu citizens, and who should be paying for new land purchases? See Sea Level Rise and the Refugee Problem

Coral Bleaching
Although coral reefs cover less than 0.2% of the ocean's area, they contain 25% of marine fish species .  An example of coral reef biodiversity are the reefs of the Florida Keys, which sustain 500 species of fish, more than 1700 species of mollusks, five species of sea turtles, and hundreds of species of sponges

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.

Decline in Populations of Antarctic Krill
Because of increasing temperatures, areas of sea ice in the Antarctic Peninsula region have diminished significantly. And the algae that grows on the underside of the shrinking sea ice is therefore also diminishing. The algae is a food source of krill, which is also disappearing in antarctic waters. Scientists report a tenfold decline in krill populations during the past 10 years. The British Antarctic Survey (BAS) completed a study in November 2004 saying that there has been an 80 percent decline in krill since the 1970's.

Besides a decline in its foods source, part of the problem of disappearing krill is the growth in numbers of other tiny marine animals called salps. Warming antarctic waters have brought about a population explosion of the salp, a jellyfish-like creature, which feeds on another krill food-source, phytoplankton. And as krill is a food source of the Adelie penguin, the latter is also disappearing. University of Montana ecologist William Fraser has studied the Adelie penguins for 22 years and has seen their numbers drop 40%. Besides the lack of krill, Fraser believes that warmth could be causing problems for the penguin by bringing spring snowfall that buries the Adelie's eggs under snowbanks. 

Severe Diseases Caused by Climate Change
A recent study by New Zealand doctors, researchers at the Wellington School of Medicine's public health department said outbreaks of dengue fever in South Pacific islands are directly related to global warming.