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Assess the effects on the carbon cycle of incineration and landfill approaches to waste disposal in urban areas. - AQA - A-Level Geography - Question 3 - 2022 - Paper 2
Question 3
Assess the effects on the carbon cycle of incineration and landfill approaches to waste disposal in urban areas.
Worked Solution & Example Answer:Assess the effects on the carbon cycle of incineration and landfill approaches to waste disposal in urban areas. - AQA - A-Level Geography - Question 3 - 2022 - Paper 2
Step 1
Assess the effects on the carbon cycle of incineration approaches
Answer
Incineration of waste primarily impacts the carbon cycle through the release of carbon dioxide (CO₂) into the atmosphere. In 2017, UK incinerators produced approximately 11 million tonnes of CO₂, contributing to atmospheric carbon levels and enhancing the greenhouse effect.
Furthermore, incineration reduces the amount of organic waste in landfills, which decreases methane emissions—a potent greenhouse gas target for mitigation. However, the incineration process also generates ash, which contains heavy metals that can pose environmental challenges if not handled properly. Overall, incineration demonstrates a dual effect: it mitigates landfill use and associated methane emissions but increases CO₂ levels.
Step 2
Assess the effects on the carbon cycle of landfill approaches
Answer
Landfill approaches to waste disposal significantly affect the carbon cycle by releasing greenhouse gases, primarily methane, during the anaerobic decomposition of organic matter. Landfills can emit substantial amounts of methane—estimated at around 438 kilotons per year from an AEB owned by a major city. This methane release accounts for a significant portion of urban emissions and aggravates climate change.
Moreover, while landfills can also sequester some carbon, they require management strategies to minimize emissions. The retention of carbon within landfill sites can be considered beneficial; however, the potential for leachate and other contaminants can simultaneously pose risks to surrounding ecologies.