Unfinished Business: Why the Acid Rain Problem Is Not Solved

The report asserts that while the 1990 Clean Air Act Amendments reduced sulfur dioxide and nitrogen oxide emissions, ecosystems in North America remain damaged due to a 150-year accumulation of acidic compounds. It documents ongoing damage to aquatic life, forests, and wildlife, and argues that biological recovery requires emission cuts up to 80 percent beyond the 1990 mandates. The authors state that affordable technologies, such as scrubbers and renewable energy, are available to achieve these deeper reductions.

• Despite reductions from the 1990 Clean Air Act Amendments, acid rain continues to cause significant ecological damage across North America, including the decline of Atlantic salmon in Nova Scotia, damage to nearly 100,000 Canadian lakes, and the loss of fish diversity in northwest Pennsylvania.
• Biological recovery of acid-sensitive areas in North America is projected to begin only by mid-century if emission cuts of up to 80 percent beyond the 1990 Clean Air Act Amendments are implemented.
• Acid rain causes severe physiological damage to fish by releasing toxic aluminum from soils, which disrupts blood chemistry and can lead to heart failure.
• Forests are suffering from nutrient leaching and direct toxicity; red spruce have seen mortality rates of over 50 percent in the Adirondack and Green Mountains, while sugar maples experience poor regeneration and loss of vigor.
• Acidification impacts wildlife through habitat alteration and food chain disruption, affecting amphibians in temporary ponds and potentially causing poor reproduction in birds due to calcium deficiency.
• The report identifies affordable technologies to achieve the necessary deep reductions, including flue gas desulfurization (scrubbers) for sulfur dioxide and selective catalytic reduction (SCR) for nitrogen oxides, alongside energy efficiency and renewables.

APA

Baum, E. (2001). Unfinished Business: Why the Acid Rain Problem Is Not Solved. Clean Air Task Force. https://cdn.catf.us/wp-content/uploads/2019/10/21093515/Acid_Rain_Report.pdf

Chicago

Baum, Ellen. Unfinished Business: Why the Acid Rain Problem Is Not Solved. Clean Air Task Force, 2001. https://cdn.catf.us/wp-content/uploads/2019/10/21093515/Acid_Rain_Report.pdf.

Wikipedia

{{cite report |last1=Baum |first1=Ellen |title=Unfinished Business: Why the Acid Rain Problem Is Not Solved |publisher=Clean Air Task Force |date=October 2001 |url=https://cdn.catf.us/wp-content/uploads/2019/10/21093515/Acid_Rain_Report.pdf |access-date=23 October 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{baum2001unfinished, author = {Baum, Ellen}, title = {{Unfinished Business: Why the Acid Rain Problem Is Not Solved}}, institution = {Clean Air Task Force}, year = {2001}, month = oct, url = {https://cdn.catf.us/wp-content/uploads/2019/10/21093515/Acid_Rain_Report.pdf}, urldate = {2026-10-23}, note = {Indexed by Climate Insights Directory} }