Year 10 Science · Unit 2 · Lesson 5
Challenge Worksheet
Learning Goals
Evaluate the claim
Someone claims...
"Acid rain is a solved problem, we don't need to worry about it anymore. Since the 1990s, Australia and Europe have drastically reduced SO₂ emissions from coal-fired power stations by installing flue-gas desulfurisation scrubbers, and the average pH of rainfall has recovered significantly. Scientists have confirmed that acid rain damage to lakes and forests is now reversing. This shows that pollution problems can always be fixed quickly with the right technology, and acid rain should be removed from science curricula as a historical issue."
(a) What part of this claim is supported by real scientific evidence about SO₂ reduction and ecosystem recovery? Be specific.
(b) Identify at least two overstatements or errors in this claim. Consider: other sources of acid rain, the speed of recovery, ongoing CO₂-driven acidification, and regions where acid rain remains severe.
(c) What evidence or extra information would you need to fully evaluate whether acid rain is truly "solved" in Australia? Describe two specific types of data you would want to see before agreeing with this claim.
1. Australian soils in eastern and southern parts of the continent are increasingly acidic due to both natural organic acids and nitrogen fertilisers. Propose two chemical remediation strategies, one short-term and one long-term, that a farmer could use. Explain the chemistry behind each strategy.
2. Forests damaged by acid rain show symptoms including needle browning, reduced growth, and death of soil microbes. Using your chemical knowledge, explain the chain of events from acid rain falling on a forest to a tree dying. Include at least three chemical steps.
Wrap Up
In one sentence, what was the main idea of this lesson?