Mitigation and Adaptation Strategies

Question 1

investigate possible human-induced causes for the enhanced greenhouse effect, including:
- land use and land cover change

Answer 1

• Using land for agricultural activities releases greenhouse gases due to the utilisation of fertilisers, gases produced by animal digestion and manure management
• The production, transport and application of nitrogen-rich fertilisers, like processed manure and urea, releases nitrous oxide
• As ruminant animals, like cows, sheep and goats, digest their food, microorganisms in their gut undergo microbiological fermentation to breakdown cellulose; a product of this process is methane
• As the manure of agricultural animals decomposes, methane and nitrous oxide are released
• When changing land cover, native vegetation and regrowth is removed and the carbon stored in dead trees and vegetation is burned, which releases carbon dioxide

Question 2

Geo-engineering strategies (mitigation strategy)
- Carbon sequestration

Answer 2

• Carbon dioxide released from the combustion of fossils fuels and is captured and injected underground for storage; this prevents the accumulation of carbon dioxide in the atmosphere
• It was tested in Texas and prevented 20 million tonnes of carbon dioxide from entering the atmosphere
• It is useful in the short-term, but its long-term impact cannot be determined; carbon dioxide can leak from underground which diminishes its usefulness

Question 3

Geo-engineering strategies
- Solar radiation

Answer 3

• Sulfur dioxide aerosols are injected into the atmosphere to create a cooling effect and reflect incoming solar radiation
• According to the Intergovernmental Panel on Climate Change (IPCC), aerosols take 2-5 years to filter out of the atmosphere and would need to be periodically injected, making this strategy expensive
• The IPCC also cautions that this strategy may cause further climate problems in the future, like changing storm movements and precipitation patterns, which invalidates its usefulness

Question 4

Alternative energy sources
- Solar power

Answer 4

• The sun’s heat is harnessed to produce steam and electricity; this heat is too weak to boil water so it is concentrated using solar power stations with thousands of mirrors that focus sunlight onto the top of the tower
• The tower stores pipes filled with water or molten salt, which is heated to 700°C and spins a turbine
• Radiant energy is transformed into electricity through photovoltaic cells, which are thin layers of silicon semiconductors combined with other elements that produce a voltage in sunlight
• Solar power doesn’t emit pollution nor greenhouse gases and is renewable; however, it is expensive, doesn’t work during extended cloudy periods and the solar panels can be damaged by hail storms