The greenhouse effect Topic 5.2

Assessment Statements 5.2.1 Draw and label a diagram of the carbon cycle to show the processes involved. 5.2.2 Analyse the changes in concentration of atmospheric carbon dioxide using historical records. 5.2.3 Explain the relationship between rises in concentrations of atmospheric carbon dioxide, methane and oxides of nitrogen and the enhanced greenhouse effect. 5.2.4 Outline the precautionary principle. 5.2.5 Evaluate the precautionary principle as a justification for strong action in response to the threats posed by the enhanced greenhouse effect. 5.2.6 Outline the consequences of a global temperature rise on arctic ecosystems.

Draw and label a diagram of the carbon cycle to show the processes involved.

Analyze the changes in concentration of atmospheric carbon dioxide using historical records.

How the greenhouse effect works Explain the relationship between rises in concentrations of atmospheric carbon dioxide, methane and oxides of nitrogen and the enhanced greenhouse effect. How the greenhouse effect works Sunlight enters Earth’s atmosphere b/c the gases of the atmosphere are transparent to light Most is reflected off surface Some is transferred into heat energy and warms the planet which in turn radiates much back to the atmosphere Greenhouse gases trap heat in atmosphere

Carbon, methane, and oxides of nitrogen are main culprits Earth is undergoing global warming b/c human-generated greenhouse gases are causing the atmosphere to retain more and more heat Carbon, methane, and oxides of nitrogen are main culprits Oxides of nitrogen: Burning fossil fuels Organic and commercial fertilizers Industrial processes Methane: Cattle ranching Waste disposal in landfills Production and distribution of natural gas

Outline the precautionary principle. An ethical theory which says that action should be taken to prevent harm even if there is not sufficient data to prove that the activity will have severe negative consequences

Evaluate the precautionary principle as a justification for strong action in response to the threats posed by the enhanced greenhouse effect. Preventative action should be taken now to reduce carbon emissions and greenhouse gases before it’s too late Those who wish to continue producing excess greenhouse gases should prove that there are no harmful effects before continuing Concerned scientists say that money spend now on preventative measures is not money wasted Prevention is better than cure

Outline the consequences of a global temperature rise on arctic ecosystems. More and more ice is melting every year Less snow and more frozen rain in the winter Some regions which never had them before are now populated with mosquitoes Certain woody shrubs are proliferating on warmer soils where once there were only mosses and lichens on tundra Bird species such as robins have moved into areas where they are so foreign to the local people that a name for them does not exist in their language

Ecosystems are changing Intact ice has capacity to harbor algae on its underside; less ice, less algae, less photosynthesis, less food Less ice, more open water for seals to come up for air and thus polar bears make fewer kills Detritus frozen in tundra will thaw and begin to decompose, releasing more carbon dioxide and methane