The Greenhouse Effect Earths atmosphere does the same thing as the greenhouse. Gases in the atmosphere such as carbon dioxide do what the roof of a greenhouse does. During the day, the Sun shines through the atmosphere. Earths surface warms up in the sunlight. At night, Earths surface cools, releasing the heat back into the air. But some of the heat is trapped by the greenhouse gases in the atmosphere. Thats what keeps our Earth a warm and cosy 59 degrees Fahrenheit, on average.
Carbon Dioxide Plants take in CO2. They keep the carbon and give away the oxygen. Animals breathe in the oxygen and breathe out carbon dioxide. Plants and animals depend on each other. It works out well. For hundreds of millions of years, plants and animals have lived and died. Their remains have gotten buried deep beneath Earths surface. So what happens to all this dead plant and animal stuff? It turns into what we call fossil fuels: oil, coal, and natural gas. This is the stuff we now use to energize our world. We burn these carbon-rich materials in cars, trucks, planes, trains, power plants, heaters, speed boats, barbecues etc.
Heres the big, important thing about CO2: Its a greenhouse gas. That means CO2 in the atmosphere works to trap heat close to Earth. It helps Earth to hold on to some of the energy it gets from the Sun so the energy doesnt all leak back out into space. If it werent for this greenhouse effect, Earths oceans would be frozen solid. Earth would not be the beautiful blue and green planet of life that it is.
Burning Fossil Fuels Over the last century the burning of fossil fuels like coal and oil has increased the concentration of atmospheric carbon dioxide (CO2). This happens because the coal or oil burning process combines carbon with oxygen in the air to make CO2. To a lesser extent, the clearing of land for agriculture, industry, and other human activities have increased concentrations of greenhouse gases.
Human Activities The industrial activities that our modern civilization depends upon have raised atmospheric carbon dioxide levels. Human- produced greenhouse gases such as carbon dioxide, methane and nitrous oxide have caused much of the observed increase in Earths temperatures over the past 50 years. It is said the rate of increase in global warming due to these gases is very likely to be unprecedented within the past 10,000 years or more.