Essential Idea:
Concentrations of gases in the atmosphere
affect climates experienced at the Earth’s surface
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 fossilised organic matter
Applications:
- 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