When we wake up in the morning, sometimes we now that it’s going to be raining that day, or sunny, or even snowing which means no school…hopefully. Climate is the average weather over many years. It changes gradually, and lasts for a long time like during the four seasons. Many, many, many years, we’ll say millions of years ago many of the earth’s land was under ice, for example a “few thousand years ago UK was under ice,” EPA scientists say. Earth has warmed up really fast, and still is. This is called Global Warming.
How is the Earth’s climate changed?
How is earth warmed up…obviously from the sun, our number one resource for energy and light. But many things block the heat from being released such as the greenhouse gases. These greenhouse gases are Carbon Dioxide, Nitrous Oxide, Methane, and Water Vapor. The image beside shows how that works…but it mostly works like a regular greenhouse works. That’s why they call it the greenhouse effect. From all these greenhouse gases…it warms up the earth…maybe in the future too hot for us to survive.
Greenhouse Gases
- Carbon dioxide comes from many natural sources such as volcanoes, soils, oceans, and living things. Plants soak up carbon dioxide from the atmosphere as they grow and the ocean acts like a sink for carbon dioxide to be stored in. Carbon dioxide is a key greenhouse gas because it is common and increasing because of human activity such as cars to other engines that makes life easier for the humans.
- Nitrous oxide comes from soils, oceans and burning wood and fossil fuels. Its greenhouse effect is 320 times greater than carbon dioxide, but it is rare in the atmosphere.
- Water vapour is the most common and strongest greenhouse gas. Lots, lots of water evaporates from the oceans, mostly closer to the equator since its hotter there.
- Methane is formed when things rot without oxygen. It has 25 times more greenhouse effect than carbon dioxide, and its also rare in the atmosphere.
Many of our activities make greenhouse gases.
- Burning Fossil Fuel
Fossil fuels (coal, gas & oil) are the remains of organisms that have been buried since the dinosaurs walked the Earth. We burn fossil fuel in power stations and to heat our houses. Burning fossil fuels releases carbon that has been trapped for millions of years and adds carbon dioxide to the atmosphere. Carbon dioxide levels have increased by 25% since the industrial revolution.
- Driving Cars
Petrol is a fossil fuel, so we add carbon dioxide to the atmosphere by burning it. Car exhausts also contain many other polluting chemicals.
- Deforestation
Huge areas of forest are being cut down all over the world. When trees are burnt, the carbon that they locked away is released as carbon dioxide.
- Landfill sites
When we throw food and garden waste into our rubbish bins, it gets buried in landfill sites. As it rots under piles of other rubbish, it creates methane.
- CFCs For Fridges and Aerosols
CFC stands for chlorofluoro-carbon. CFCs do not exist naturally. Wemake them using industrial processes. They are used for coolants in fridges andpropellants in aerosols. There are only tiny amounts in the atmosphere (less than 0.000001%), but they have around 10,000 times the ‘greenhouse effect’ of carbon dioxide. CFCs also destroy ozone – an important part of the upper atmosphere. Some ozone friendly CFCs are still greenhouse gases.
- Farming
When farmers add nitrogen fertiliser to the soil, some of it is turned into nitrous oxide, a powerful greenhouse gas. Cows produce methane when grass ferments in their stomach. There are an estimated 1.2 billion cattle in the world, all adding to the world’s greenhouse gases.
Sources
Image-http://www.effectofglobalwarming.com/images/What-is-global-warming-img.jpg
http://www.funnyandjokes.com/wp-content/uploads/2007/06/shark-global-warming.jpg
