Understandings:

• Carbon dioxide and water vapour are the most significant greenhouse gases.
• Other gases including methane and nitrogen oxides have less impact.
• The impact of a gas depends on its ability to absorb long wave radiation as well as on its concentration in the atmosphere.
• The warmed Earth emits longer wavelength radiation (heat).
• Longer wave radiation is absorbed by greenhouse gases that retain the heat in the atmosphere.
• Global temperatures and climate patterns are influenced by concentrations of greenhouse gases.
• There is a correlation between rising atmospheric concentrations of carbon dioxide since the start of the industrial revolution 200 years ago and average global temperatures.
• Recent increases in atmospheric carbon dioxide are largely due to increases in the combustion of fossilized organic matter.