GLOBAL WARMING

Global warming is the increase in the average temperature of the Earth's nearsurface

air and oceans since the mid20th

century and its projected continuation.

Global surface temperature increased 0.74 ± 0.18 °C (1.33 ± 0.32 °F) during the

last century.

Causes of Global Warming

"The effects of global warming and climate change are of concern both for the

environment and human life. The major cause of which is the continuous

emission of carbon dioxide in the atmosphere."

Carbon Dioxide from Power Plants

Coal accounts for 93 percent of the emissions from the electric utility industry. It 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.

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. Levels of atmospheric methane have

risen 145% in the last 100 years. Methane is derived from sources such as rice paddies,

bovine flatulence, bacteria in bogs and fossil fuel production.

Solar Variation

Variations in solar output have been the cause of past climate changes. Although solar

forcing is generally thought to be too small to account for a significant part of global

warming in recent decades, a few studies disagree, such as a recent phenomenological

analysis that indicates the contribution of solar forcing may be underestimated.

 

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Aerosols and soot

Global dimming, a gradual reduction in the amount of

global direct irradiance at the Earth's surface, has

partially counteracted global warming from 1960 to the

present. The main cause of this dimming is aerosols

produced by volcanoes and pollutants. These aerosols

exert a cooling effect by increasing the reflection of

incoming sunlight.

James Hansen and colleagues have proposed that the

effects of the products of fossil fuel combustion, CO2 and

aerosols, have largely offset one another in recent

decades, so that net warming has been driven mainly by

nonCO2

greenhouse gases.

Water Vapor in the Atmosphere Increasing

Water vapor is the most prevalent and most powerful greenhouse gas on the planet, and its

increasing presence is the result of warming caused by carbon dioxide, methane and other

greenhouse gases. Water vapor holds onto twothirds

of the heat trapped by all the

greenhouse gases. 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.

Nitrous oxide

Another greenhouse gas is Nitrous oxide (N2O), a colourless, nonflammable

gas with a

sweetish odour, commonly known as "laughing gas", and sometimes used as an anesthetic.

Nitrous oxide is naturally produced by oceans and rainforests.

Deforestation

After carbon emissions caused by humans, deforestation is the second principle cause of

atmospheric carbon dioxide. Deforestation is responsible for 2025%

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.

 

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Evidences and Effects

"If the voices of future generations could be heard, they would plead for

action on climate change. The unborn children of tomorrow will bear the

heavy burden of our indifference."

Rise in Global

Temperature

The figure shows the difference in

instrumentally determined surface

temperatures between the period January

1999 through December 2008 and "normal"

temperatures at the same locations, defined

to be the average over the interval January

1940 to December 1980. The average

increase on this graph is 0.48 °C, and the

widespread temperature increases are

considered to be an aspect of global

warming.

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.

The

park's Grinnell Glacier is already 90% gone. Pictured here is

the glacier just prior to its meltdown.

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 2025%

of parts of the glacier.

Ice

cores taken from the Dunde Ice Cap in the Qilian Mountains on the northeastern margin

of the QinghaiTibetan

Plateau indicate that the years since 1938 have been the warmest in

the last 12,000 years

 

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The

melting is accelerating. The Lewis Glacier on Mt. Kenya (In Kenya) has lost 40% of its

mass during the period 19631987

or at a much faster clip than during 18991963.

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.

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.

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. Global warming is projected to significantly increase the range

conducive to the transmission of both dengue and yellow fevers.

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 hightech

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 lowlying

areas, when a storm occurs. Sea level increase

could worsen, if the present trend continues.

 

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Current News

"So we'll wait. Not enough people dying yet and not enough property

destroyed. We'll keep our heads in the blazing hot sand until we

actually feel the flames of a fullfledged

catastrophe."

March 25, 2008...Satellite

imagery from the University of

Colorado at Boulder's National

Snow and Ice Data Center

shows a portion of Antarctica's

massive Wilkins Ice Shelf has

begun to collapse because of

rapid climate change in a fastwarming

region of the

continent. According to Ted

Scambos, lead scientist at

NSIDC, "If there is a little bit

more retreat, this last 'ice

buttress' could collapse and

we'd likely lose about half the

total ice shelf area in the next

few years".

January 15, 2008...The year 2007 tied 1998 as the second warmest year on record; 2005

being the warmest year. An analysis by NASA's Goddard Institute for Space Studies (GISS)

showed that "the unusual warmth in 2007 is noteworthy because it occurs at a time when

solar irradiance is at a minimum and the equatorial Pacific Ocean is in the cool phase of its

natural El Nino – La Nina cycle."

August 30, 2007...NOAA recorded that last year came very close to being the warmest on

record, since 1998. Of the past 12 years 11 of them have been found to be the warmest on

record, since recordkeeping

began in 1895.

 

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What You Can Do:

· Use Compact fluorescent bulbs.

· When replacing home appliances, use energy efficient models. For example,

replacing an old refrigerator using 320 watts with a new one using 85 watts could

make a big difference. When buying appliances, look for the BEE labels.

· Use cars and light trucks that get good gas mileage. In fact tell your friends that

driving a sports utility vehicle adds to global warming and pollution. SUVs emit

43% more globalwarming

pollutants (28 pounds of carbon dioxide per gallon)

and 47% more air pollution than the average car. An SUV is 4 times as likely to

rollover in an accident.

· Help promote community carpooling.

· Promote the construction of bike lanes, especially bike lanes that have an outside

curb separating auto traffic and bikes.

· Place an insulating cover around water heater.

· Take public transit whenever possible.

· When shopping for groceries, bring your own cloth bag to the market. Not using

paper grocery bags help saves trees that absorb carbon dioxide.