4.4  Climate Change

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Essential Idea:

Concentrations of gases in the atmosphere 

affect climates experienced at the Earth’s surface


  • 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 fossilised organic matter


  • Threats to coral reefs from increasing concentrations of dissolved carbon dioxide
  • Correlations between global temperatures and carbon dioxide concentrations on Earth
  • Evaluating claims that human activities are not causing climate change