4.4 Flashcards
which gases have the greater impacts on the green house effect
carbon dioxide and water vapour
what does it mean that the earth is a closed system
not much escapes its gravity and atmosphere, meaning the amount of carbon dioxide and water on this planet is finite, the state of the molecules can change.
what are the two ways carbon dioxide is taken out o f the atmosphere
by photosynthesis and by dissolving in oceans and lakes
what are greenhouse gases
gases found in the atmosphere such as water value, carbon dioxide, methane and nitrous oxides, that contribute to the greenhouse effect.
what is water vapour
water found in the atmosphere in a gaseous form, It is the most abundant greenhouse gas
what is carbon dioxide
a gas found in the atmosphere that is a main greenhouse gas
green house gases
water vapour 60% carbon dioxide 26% methane 4.4% 1.5% N2O 0.1 others
how does a gas contribute to the greenhouse effect
it needs to be able to absorb longer wavelength radiation such as methane and nitrous oxides that can absorb longer wavelength or infrared radiation.
how does methane contribute to the greenhouse effect
traps 20% more heat than the same amount of carbon dioxide and causes faster warming of the planet
how does methane occur
naturally, by escaping from melting ice and tundra in the arctic
it escapes from landfills and marshes and is it produced by cattle
how are nitrous oxides emitted
by certain bacteria, small quantities may also be produced by lightning during thunderstorms
which animal emits the most tonnes of CO2
cattle
how much is the volume of greenhouse gases in the earths atmosphere
less than 1%
why is the earths atmosphere warmed
because certain gases in the atmosphere absorb radiation and retain heat
two factors that determine how much a greenhouse gas will contribute to global warming are
ability to absorb long wave radiation, abundance in atmosphere
why do some gases cause a greenhouse effect but not others
some gases can absorb longer wavelengths of light and re-emit them as heat.
step one of the greenhouse effect
- solar radiation from the sun spans the electromagnetic spectrum from approximately 100 to 4000 nanometers (nm) with visible light compromising about 44% of its emissions. After passing through the ozone layer, the layer of the atmosphere that blocks UV ration but is not considered a greenhouse gas, only short wavelength radiation form the sun reaches the earths surface. Some of the short wavelength radiation is reflected but most passes though the greenhouse gases to the earths surface.
step two of the greenhouse effect
the earth absorbs some of this shortwave radiation while some if reflected. This absorbed radiation is then re-emitted, mainly as infrared hear, which is a long wave radiation,
step 3 and 4 of the greenhouse effect
- part of this longer wavelength radiation escapes earth’s atmosphere into space, however, much of it is absorbed by greenhouse gases in the atmosphere.
- The greenhouse gases re-remit the absorbed light in all directions as heat. Some of this radiation is re-emitted towards the earth, thus contributing to global warming .
what is radiation
energy that may be a subatomic particle, for example an electron (gamma rays) or in the form of an electromagnetic wave, for example ultraviolet radiation
what is solar radiation
energy from the sun that comes in the form of electromagnetic waves. This includes many types of waves such as visible with or ultraviolet light
what is the ozone layer
03 is a layer of the earths atmosphere that protects the Earth from ultraviolet radiation coming from the sun. It is not considered a greenhouse gas because it does not absorb long wave radiation
What is UV radiation
ultraviolet radiation is a type of shortwave radiation coming from the sun, but is filtered out by the ozone layer of the atmosphere.
What is long-wavelength radiation
also known as infrared light, a type of radiation that is emitted from the Earth and its atmosphere. Examples include, microwaves and radiowaves.
