What is Greenhouse Effect ?

O The greenhouse effect is a natural

process that warms the Earth’s surface.

When the Sun’s energy reaches the

Earth’s atmosphere, some of it is reflected

back to space and the rest is absorbed

and re-radiated by greenhouse gases.

Some Works on Greenhouse Effect

O The existence of the greenhouse effect was argued

for by Joseph Fourier in 1824.

O John Tyndall declares the reasoned experimental

observations in 1859.

O Svante Arrhenius revised the observations of John

Tyndall in more numerical datas in 1896.

O Global warming refers to a rise in the temperature of

the surface of the earth

O An increase in the concentration of greenhouse gases

leads to an increase in the magnitude of the

greenhouse effect ( called enhanced greenhouse effect

Causes of Greenhouse Effect

OGreenhouse Gases: By their percentage contribution to the greenhouse effect on Earth the four major gases are:

water vapor, 36–70%

carbon dioxide, 9–26%

methane, 4–9%

ozone, 3–7%

O Ozone Layer Depletion: A variety of biological consequences such as increases in sunburn, skin cancer, cataracts, damage to plants, and reduction of plankton populations in the ocean's photic zonemay result from the increased UV exposure due to ozone depletion.

O Between 2030 and 2050, climate change is expected to cause approximately 250 000 additional deaths per year, from malnutrition, malaria, diarrhoea and heat stress.

O Extreme high air temperatures contribute directly to deaths from cardiovascular and respiratory disease, particularly among elderly people. In the heat wave of summer 2003 in Europe for example, more than 70 000 excess deaths were recorded.

O Climate change is expected to cause approximately 250 000 additional deaths per year between 2030 and 2050; 38 000 due to heat exposure in elderly people, 48 000 due to diarrhoea, 60 000 due to malaria, and 95 000 due to childhood undernutrition.

Increased Temperature

Rising Sea Level

Habitat Damage and SpeciesExtinction

More Severe Storms

Droughts

Reduce, Reuse, Recycle

Buying products with minimal packaging will

help to reduce waste. By recycling half of

your household waste, you can save 2,400

pounds of carbon dioxide annually

Replace Your Light Bulbs

Wherever practical, replace regular light bulbs

with compact florescent light (CFL) bulbs.

Replacing just one 60-watt incandescent light

bulb with a CFL will save you $30 over the life of

the bulb. CFLs also last 10 times longer than

incandescent bulbs, use two-thirds less energy,

and give off 70 percent less heat. If every

Canadian family replaced one regular light bulb

with a CFL, it would eliminate 90 billion pounds

of greenhouse gases, the same as taking 7.5

million cars off the road.

Use the "Off" Switch

Save electricity and reduce global warming by

turning off lights when you leave a room, and

using only as much light as you need. And

remember to turn off your television, stereo and

computer when you're not using them. It’s also a

good idea to turn off the water when you’re not

using it. While brushing your teeth, shampooing

the dog or washing your car, turn off the water

until you actually need it for rinsing.

Plant a Tree

If you have the means to plant a tree, start

digging. Trees absorb carbon dioxide and

give off oxygen. A single tree will absorb

approximately one ton of carbon dioxide

during its lifetime.

Encourage Others to Conserve

Share information about recycling and

energy conservation with your friends,

neighbors and co-workers, and take

opportunities to encourage public officials to

establish programs and policies that are

good for the environment.

Not All Scientists Agree

While the majority of mainstream scientists agree that global warming is a serious problem that is growing steadily worse, there are some who disagree.

John Christy, a professor and director of the Earth System Science Center at the University of Alabama in Huntsville is a respected climatologist who argues that global warming isn't worth worrying about.

Christy reached that opinion after analyzing

millions of measurements from weather

satellites in an effort to find a global

temperature trend. He found no sign of

global warming in the satellite data, and now

believes that predictions of global warming

by as much as 10 degrees Fahrenheit by

the end of the 21st century are incorrect.