WHAT IS THE EFFECT OF GREENHOUSE GASES ON GLOBAL WARMING?

Submitted to: Mr. Imran Shaukat

Submitted by: AHSAN MAQBOOL 2012-AG-3746 B.Sc. Agri. Engg. Section C1

WHAT IS GLOBAL WARMING?

Unusual rapid increase or change in Earths average temperature called global warming over the past

century primarily released of greenhouse gases from people burn as fossil fuel. The global average

surface temperature rose 0.6 to 0.9 degree Celsius between 1906 and 2005 that rate of temperature

increases double from last 50years.

How does this global warming compare to previous changes in the Planet climate?

How can be certain that human-released greenhouse gases are causing global warming?

How much more will the Earth warm?

How will Earths respond replying these questions in perhaps the most significant scientific

Environmental challenge of our time?

GREENHOUSE GASES

Greenhouse gases trap the heat in the atmosphere entering or leaving envelop of the Earth. What so

ever its coming from sunlight in the form of UV, IR radiation or people are adding several types of gases

to the atmosphere and each gas effect the climate change or temperature increases.

GREENHOUSE EFFECT

Greenhouse effect is ability of these gases to trap energy in the atmosphere and capability to

stays/retain more heat energy on Earth.

EARTHS NATURAL GREENHOUSE EFFECT

Earths temperature begins with sunlight. About 30% of sunlight reflects back in the space by the

bright surface of Ice, Clouds etc. Rest of 70% remaining in the atmosphere and absorbed by the ocean.

That heat energy radiate the air, rocks and warm up seas, this energy travel into the atmosphere where

it as absorbed by water vapor and greenhouse gases like Carbon dioxide (CO2), Methane (CH4).

Microscopic water or greenhouse gases molecules turn into tiny heater when they absorb the

energy radiating from the Earths surface-like the bricks in the fire they radiate even after the fire goes

out and emitted radiation in all direction. That energy radiation back towards Earth heats both the lower

atmosphere and surface enhancing the heat. They are getting direct from sunlight and these radiations

cause the warming of atmosphere.

The natural greenhouse effect is beneficial for life on Earth due to the absorption of heat by the

atmosphere. If there were no greenhouse affects the Earths surface temperature would be a very chilly

instead of comfortable that is today.

EARTHS ARTIFICAL GREENHOUSE EFFECT

Due to human activity the concentration of greenhouse gases in the atmosphere with increasing rate.

Mostly by burning of fossil fuel but also deforestation on the land due to Industrialization began in 1750.

CO2 have been increases 38% as 2009 and Methane level increases 148% in the atmosphere.

Due to more concentration of greenhouse gases molecule more IR energy radiation emitted by the

surface ends being absorb by the atmosphere. The extra energy from a warmer atmosphere radiates

back down to the surface. Earths surface temperature rises by increasing the concentration of

greenhouse gases we making Earths atmosphere a more efficient greenhouse.

WHICH GASES CAUSES GREENHOUSE EFFECTS?

The principal forcing greenhouse gases are:

1. Carbon dioxide (CO2)

2. Methane (CH4)

3. Nitrous oxide (N2O)

4. Fluorinated gases

The main feedback greenhouse gas is Water vapor.

Forcing greenhouse gases take many years to leave the atmosphere. CO2, CH4,

N2O and the fluorinated gases are all well-mixed gases in the atmosphere. They do

not react to changes in either temperature or air pressure and thus do not get

removed easily like water that condenses to become rain or snow. Their long

atmospheric lifetimes allow them to have a lasting effect on global warming and

climate change.

Water vapor on the other hand has a residence time of a few days. It is a

highly active component of the climate system that responds rapidly to changes in

conditions by either condensing into rain or snow, or evaporating to return to the

atmosphere. Thus the impact of the greenhouse effect is primarily circulated

through water vapor, and it acts as a fast feedback, accentuating the warming

provided by the forcing greenhouse gases.

CO2 and the other forcing greenhouse gases are the key gases within the Earth's

atmosphere that sustain the greenhouse effect and control its strength. In fact, the

greenhouse effect would collapse were it not for the presence of CO2 and the other

non-condensing greenhouse gases.

Greenhouse gases greatly affect the temperature of the Earth. Without them,

surface temperatures would be on average about 32.5C colder than the present

average of 14.4C (57.9F),making life on Earth as we know it not possible.

Greenhouse gases are not, inherently, a bad thing. But the growing concentration

of greenhouse gases in the atmosphere has been raising average temperatures

around the world.

CO2, CH4 and N2O are emitted to the atmosphere through natural processes as

well as human activities (use of fossil fuels, industrial production, etc). The

fluorinated gases on the other hand, are created and emitted almost exclusively

through human activities.

Since the Industrial Revolution, which began in the 18th century, human

activities have been a major source of all forcing greenhouse gases. Human

activities have led to a sharp and dangerous increase of these gases within the

Earth's atmosphere, so much so that the growth of all forcing greenhouse gas

concentrations is now directly controlled by humans.

PRACTICAL APPROCACH FOR MINIMIZING

EMITION OF GREENHOUSE GASES

We want to minimize or stop the emitions of greenhouse by adopting following recommendation:

Replacing one regular light bulb with a compact flourescent light buld will save 150

pounds of carbon dioxide a year.

We can save 2,400 pounds of carbon dioxide per year by recycling just half of your

household waste.

Keeping your tires inflated properly can improve your gas mileage by more than 3

percent. Every gallon of gasoline saved keeps 20 pounds of carbon dioxide out of the

atmosphere.

It takes a lot of energy to heat water. Use less hot water by taking shorter and cooler

showers and washing your clothes in cold or warm instead of hot water (more than 500

pounds of CO2 saved per year).

You can save 1,200 pounds of carbon dioxide if you reduce your garbage by 10 percent.

Moving your thermostat down just 2 degrees in winter and up 2 degrees in summer

could save about 2,000 pounds of carbon dioxide a year.

A single tree will absorb one ton of carbon dioxide over its lifetime.

Simply turning off your television, DVD player, stereo and computer when you're not

using them will save you thousands of pounds of carbon dioxide a year.

My approach

Walk, bike, carpool or take mass transit more often. You'll save one pound of

carbon dioxide for every mile you don't drive.