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If global warming is to stay below 2 °C, there are four risks of assets stranding. First, substantial fossil fuel reserves will be stranded at the end of the fossil era. Second, this is true for exploration capital too. Third, unanticipated changes in present or expected climate policy cause discrete jumps in today's valuation of physical and natural capital. Fourth, if timing and intensity of climate policy are uncertain, revaluation of assets occurs as uncertainty about future climate policy is resolved. To highlight these four effects, we use an analytical model of investment in exploration capital with intertemporal adjustment costs, reserves depletion and market capitalization, and calibrate it to the global oil and gas industry. Climate policy implements a carbon budget commensurate with 2 °C peak warming and we allow for immediate or delayed carbon taxes and renewable subsidies. The social welfare ranking of these instruments is inverse to that of the oil and gas industry which prefers renewable subsidy and delaying taxes for as long as possible. We also pay attention to how the legislative “risk” of tipping into policy action affects the timing of the end of the fossil era, the profitability of existing capital, and green paradox effects.

If global warming is to stay below 2°C, there are four risks of assets stranding. First, substantial fossil fuel reserves will be stranded at the end of the fossil era. Second, this will be true for exploration capital too. Third, unanticipated changes in present or expected future climate policy cause instantaneous discrete jumps in today’s valuation of physical and natural capital. Fourth, if timing and intensity of climate policy are uncertain, revaluation of assets occurs as uncertainty about future climate policy is resolved. E.g. abandoning climate policy plans immediately boosts scarcity rent, market capitalization, exploration investment and discoveries. To explain and quantify these four effects, we use an analytical model of investment in exploration capital with intertemporal adjustment costs, depletion of reserves and market capitalization, and calibrate it to the global oil and gas industry. Climate policy implements a carbon budget commensurate with 2°C peak warming and we allow for different instruments: immediate or delayed carbon taxes and renewable subsidies. The social welfare ranking of these instruments is inverse to that of the oil and gas industry which prefers renewable subsidy and delaying taxes for as long as possible. We also pay attention to how the legislative “risk” of tipping into policy action affects the timing of the end of the fossil era, the profitability of existing capital, and green paradox effects.

A rapidly rising carbon tax leads to faster extraction of fossil fuels and accelerates global warming. We analyze how general equilibrium effects operating through the international capital market affect this Green Paradox. In a two-region, two-period world with identical homothetic preferences and without investment, the global interest rate falls and the Green Paradox weakens. With investment or a relatively more impatient oil-importing region, the Green Paradox may be strengthened because the future oil demand function shifts downward or because the interest rate rises. If the oil-importing region is very much more patient than the oil-exporting region, the Green Paradox may be reversed but in our calibrated model the effects are tiny. With exploration and endogenous initial oil reserves, a future carbon tax lowers cumulative oil extraction in partial equilibrium. If the boost to current oil extraction is weakened, strengthened or reversed in general equilibrium, so is the fall in cumulative extraction. A partial and general equilibrium welfare analysis of a future carbon tax, both for full and partial exhaustion, is given. The effects of stock-dependent extraction costs are separately discussed in an Appendix.