Topic 9 - Atmospheric Chemistry

• The Earth's early atmosphere was likely mostly carbon dioxide, with nitrogen and water then increasing due to volcanic activity
• Carbon dioxide then dissolved into the oceans - formed from the water vapour condensing - and then trapped into sediment
• Plants and algae then converted carbon dioxide into oxygen - reducing levels to 0.018%
• The greenhouse effect is what keeps the Earth warm - greenhouse gases absorbed long wavelength radiation reflected off the surface.
• Greenhouse Gases:

  Water vapour

  Carbon Dioxide

  Methane
• The sun emits short-wavelength radiation to the Earth. The Earth absorbs the short wavelengths and reflects long wavelengths - the greenhouse gases absorb some of the long wavelengths and reflect them in any direction - some heading back to Earth.
• Global warming is the rise in global temperatures. The Earth's climate is incredibly hard to model and predict which is why many predictive models turn out to be inccorect
• Carbon footprint is the measure of how much carbon dioxide is released into the atmosphere as a result of your actions
• Carbon monoxide is an atmospheric pollutant. It is very toxic and dangerous as it binds to the haemoglobin in red blood cells, reducing the oxygen they are able to transport around the body. It is odourless and colourless, making it very hard to detect
• Most fossil fuels release sulphur dioxide when burnt - it causes acid rain which corrodes metals an erodes stone
• Nitrogen oxides can also be release from the burning/use of fossil fuels in a car - it causes respiratory/health problems
• Carbon particulates/soot can cause health issues - made from incomplete combustion