A small, specific list: carbon, methane, particulates, and congestion (classical Pigouvian); resource extraction above the regeneration rate (severance/depletion taxes); land value — Henry George's tax on unearned location rent, which captures wealth without distorting production; financial leverage above systemic-risk thresholds; unfunded pension liabilities (force amortisation rather than rollover); monopoly rents that rest on regulatory capture rather than productivity. What it would NOT tax: labour income, corporate profits earned competitively, capital gains on productive investment, or consumption choices of competent adults.