09. Greenhouse effect
Climate change and greenhouse effect
Greenhouse effect:
http://earthguide.ucsd.edu/earthguide/diagrams/greenhouse/
Slider animation to show the increase in global surface temperature over time http://climate.nasa.gov/keyIndicators/#globalTemp.
Watch this animation http://earthguide.ucsd.edu/earthguide/diagrams/greenhouse/ on the greenhouse effect.
How much do you know of climate change? Complete the quiz below
Earth day Climate change quiz https://www.earthday.org/the-climate-change-quiz/
What is the greenhouse effect and how does it work?
Greenhouse effect is a natural process in which the gases in the Earth’s atmosphere trap longwave radiation emitted from the earth’s surface, warming the atmosphere. The earth receives shortwave radiation in the form of visible light from the sun. Some of the shortwave radiation is absorbed by the earth’s surface, which then heats up as a result. The earth’s surface then emits longwave radiation in the form of infrared radiation. The longwave radiation emitted from the earth’s surface is absorbed by the gases in the earth’s atmosphere.
Water vapour, carbon dioxide, methane, nitrous oxide ozone and halocarbons such as chlorofluorocarbons (CFCs) are good absorbers of longwave radiation. They are known as greenhouse gases and are found in the atmosphere.
Enhanced greenhouse effect
Enhanced greenhouse effect refers to an increase in the concentration of greenhouse gases in the atmosphere, leading to a rise in the global temperatures. The enhanced greenhouse effect occurs when human activity causes greenhouse gases to be released at a far greater rate than that of the natural emissions of greenhouse gases.
Concentrations of greenhouse gases such as nitrous oxide and methane have increased in the earth’s atmosphere since the Industrial Revolution in the mid-18th century. Among these gases, the most significant increase is in the amount of carbon dioxide.
Summary:
• the role of greenhouse gases in the atmosphere is vital in keeping the earth’s atmosphere and surface (land and oceans) warm and liveable for man.
• carbon dioxide, water vapour, nitrous oxide, methane, ozone and halocarbons are examples of greenhouse gases.
• the amount of greenhouse gases has increased in the atmosphere leading to an increase in heat trapped within the atmosphere, hence resulting in the enhanced greenhouse effect.