What is the Greenhouse Effect?

The greenhouse effect is a natural process. It is the process in which the Earth is able to keep warm, well much warmer than it would otherwise be. The process occurs because the gases in the earth's atmosphere trap energy from the sun. Sunlight enters the earth's atmosphere, hits the earth and the energy from the sunlight is caught by the land, water etc. This energy is used and later sent back to the atmosphere - some goes back into space but most is trapped in the earth's atmosphere. This is what keeps the earth warm, it acts a bit like a blanket.  Some of the gases used in the greenhouse effect include water vapour, carbon dioxide, methane, nitrous oxide.

How are humans altering the Greenhouse Effect?

The problem we face today is that we are effecting the natural greenhouse process. Humans are increasing existing greenhouse gases.
Greenhouse emissions are formed by everyday people, factories, vehicles and machines polluting the air.
We have increased our carbon dioxide levels through the use of cars and burning of fossil fuels like gas, coal and oil. Products that have commonly be used in factories. We have also cleared large areas of land, reducing the trees that assist in breaking carbon dioxide down and turning it into oxygen.
Methane levels have also been increased through farming. Cattle and sheep are big produces of methane as too are rice paddies and land fill, one of the common ways humans dispose of their unwanted waste.
Nitrouse oxide and cfc's and ozone have also increased due to modern development and the waste products that modern day processing causes.


What changes will occur because of increased greenhouse emissions?

Increased greenhouse gases will effect the natural greenhouse process, in effect more gases will mean a warmer temperature. Making the earth's blanket thicker so less gases escape and the earth underneath is made warmer.
The temperature rise is expected to melt polar ice caps and glaciers as well as warm the oceans, all of which will expand ocean volume and raise the sea levels by an estimated 9 to 100 cm in the next 100 years.
Also increased greenhouse emissions will cause other climate changes. It will cause some places to experience longer droughts, other areas to have increased rainfall, feircer storms, hotter days. Scientists can't yet predict the exact impact or where the changes will take place but they are very confident the increased greenhouse emissions will increase the earth's temperature and cause changes with our current climate.


What can we do to prevent greenhouse emissions?

The Kyoto Protocol calls for 38 industrialized nations to reduce their emissions by an average of 5.2 percent below 1990 levels by 2012. The United States, which currently emits more than 20 percent of the world's carbon dioxide from fossil fuels, agreed to a 7% cut below 1990 levels, while 15 nations of the EU committed themselves to an 8 percent reduction. Japan agreed to a 6 percent cut. The pact does not require any binding emission reductions for developing countries, but subsequent rounds of negotiations were set up to consider this and other issues in the years ahead.
At home there are plenty of things people can do to help. Try to select energy effecient appliances, only use energy like electricity when it is truly needed. Plant trees, don't use aerosols, conserve water. All of these little things will help or environment and help save our oceans.
 
Sources: Encarta Kids, Encarta Referance
' Greenhouse Effect' - http://en.wikipedia.org/wiki/Greenhouse_effect.
'The Greenhouse Effect' - http://www.cmar.csiro.au/e-print/open/holper_2001b.html
The Greenhouse Effect' - http://epa.gov/climatechange/kids/greenhouse.html