[en] Economic assessments of climate change impacts are commonly presented as the effect of a climate change associated with a doubling of the atmospheric concentration of carbon dioxide on the current economy. This paper is an attempt to express impact as a function of both climate change and socio-economic change. With regard to climate change, issues discussed are level versus rate of change, speed of adaptation, speed of restoration and value adjustment, and symmetry. With regard to socio-economic change, agriculture, migration and the valuation of intangible losses are addressed. Uncertainty and higher order impacts are treated briefly. It is qualitatively argued and quantitatively illustrated that these issues matter a great deal for the damage profile over the next century. A damage model, based on the author's best guesses, is presented in the Appendix

[en] Several issues relating to insurance and the damage costs of climate change are discussed. It is argued that the option of insuring climate change is severely limited because the associated damages are hardly quantifiable and little diversifiable; in addition, binding contracts are a problem on long time scales and in an international context. Hedging, consumption smoothing over time, precautionary investments and liability are not to be presented under the heading of insurance, not only because this unnecessarily and confusingly expands the traditional definition of insurance, but also because this could create a false sense of security. The impact of climate change on the profitability of the commercial insurance sector is not likely to be severe, as the insurance companies are capable of shifting changed risks to the insured, provided that they are properly and timely informed on the consequences of climate change. (author)

[en] Highlights: • Estimates of the national social cost of carbon • Large, poor countries show the highest estimates. • Income elasticity of impact is key parameter. -- Abstract: This paper uses imputed national climate change impact functions to estimate national social costs of carbon, which are largest in poor countries with large populations. The national social costs of carbon of faster growing economies are less sensitive to the pure rate of time preference and more sensitive to the rate of risk aversion. The pattern of national social costs of carbon is not sensitive to the assumed impact function, climate sensitivity, and scenario, although the global social cost of carbon is. Income convergence raises the national social costs of carbon of poorer countries, and lowers them for richer countries. Both global and national social costs of carbon are most sensitive to the income elasticity of climate change impacts, a parameter about which we know little.

[en] This paper considers the coordination of domestic markets for tradable emission permits where countries determine their own emission reduction targets, using a two-country model. Linking such schemes is beneficial to both countries but may cause the exporting country to decrease its emission reduction target and export more permits. This in turn would not only reduce the costs for both countries as less emissions have to be reduced, but it also lowers the environmental benefits of the importing country. One price instrument (tariff) and two quantity instruments (discount, quota) to prevent the exporting country from issuing more permits are examined. Each instrument restricts trade and alters the terms of trade for the two countries. The importing country (and regulator) prefers an import tariff and an import quota to a carbon discount. If the exporting country releases additional permits, the importing country should not try to keep total emissions constant, as that would be ineffective and maybe even counterproductive. Instead, the importing country should aim to keep the total import constant; this would impose costs on the exporting country that are independent of the policy instrument; an import quota would be the cheapest option for the importing country. An import quota would also stress the idea of supplementary of the flexible mechanism as it increases the share of emissions reduced domestically. Compliance and liability issues constrain the market further. However, both the importing and the exporting country would prefer that the permit seller is liable in case of non-compliance, as sellers' liability would less constrain the market

[en] The EU has proposed four flexibility mechanisms for the regulation of greenhouse gas emissions in the period 2013-2020: (1) the Emissions Trade Scheme (ETS), a permit market between selected companies; (2) trade in non-ETS allotments between Member States; (3) the Clean Development Mechanism (CDM) to purchase offsets in developing countries; and (4) trade in CDM warrants between Member States. This paper shows that aggregate abatement costs fall as flexibility increases. However, limited flexibility creates rents so that increasing flexibility raises costs in some Member States. Costs are reduced more by the CDM than by non-ETS trade. The CDM warrants market reduces costs by a small amount only; market power is a real issue. However, the warrants market is obsolete in case there is non-ETS trade. The CDM leads to price convergence between the ETS and non-ETS market. There would be one price for carbon in the European Union if the proposed limits on CDM access are relaxed slightly.

[en] This paper studies the feasibility of stringent targets for stabilizing ambient greenhouse gas concentrations using the FUND model. 170,000 policy scenarios were run, systematically varying the price of carbon, participation in climate policy, the strength of the climate feedback on the terrestrial carbon cycle, the no policy scenario, and the abatement costs. The results reveal the following. Climate policy has diminishing returns, and there is therefore a maximum to what can be achieved. The success of climate policy is hampered if, as is likely, the terrestrial biosphere turns from a carbon sink to a carbon source because of climate change. All major countries have to reduce their emissions in order to meet the more ambitious stabilization targets. The cost of climate policy would be lower if the stabilization target can be exceeded in the interim. The EU target of 2 deg. C warming above pre-industrial is infeasible under almost all assumptions. A cost-benefit analysis would endorse a target of 4.5 W m^-2 (but not much stricter than that) if all major emitters engage in abatement. Under the same condition, the median US voter would support a 3.7 W m^-2 target (but not much stricter than that). International permit trade would encourage large developing countries to reduce their emissions, but the trade flows would be substantial relative to product trade and much larger than official development aid.

[en] This paper discusses some of the elements that may characterise an efficient strategy to adapt to a changing climate. Such a strategy will have to reflect the long time horizon of, and the prevailing uncertainties about, climate change. An intuitively appealing approach therefore seems to be to enhance the flexibility and resilience of systems to react to and cope with climate shocks and extremes, as well as to improve information. In addition, in the case of quasi-irreversible investments with a long lifetime (e.g. infrastructure investments, development of coastal zones), precautionary adjustments may be called for to increase the robustness of structures, or to increase the rate of depreciation to allow for earlier replacement. Many of these measures may already have to be considered now, and could be worthwhile in their own right, independent of climate change considerations

[en] The European Commission did not publish a cost–benefit analysis for its 2020 climate package. This paper fills that gap, comparing the marginal costs and benefits of greenhouse gas emission reduction. The uncertainty about the marginal costs of climate change is large and skewed, and estimates partly reflect ethical choices (e.g., the discount rate). The 2010 carbon price in the EU Emissions Trading System can readily be justified by a cost–benefit analysis. Emission reduction is not expensive provided that policy is well-designed, a condition not met by planned EU policy. It is probably twice as expensive as needed, costing one in ten years of economic growth. The EU targets for 2020 are unlikely to meet the benefit–cost test. For a standard discount rate (3% pure rate of time preference), the benefit–cost ratio is rather poor (1/30)—so that benefits need to be very much higher, or costs very much lower than typically assumed to justify the 2020 targets. Only a very low discount rate (0% PRTP) would justify the 20% emission reduction target for 2020. - Highlights: ► First cost–benefit analysis of EU climate policy for 2020. ► Current carbon price in ETS can readily be justified by CBA. ► Emission targets for 2020 cannot be supported unless a low discount rate is chosen.

[en] A model of carbon dioxide emissions of the USA is presented. The model consists of population, income per capita, economic structure, final and primary energy intensity per sector, primary fuel mix, and emission coefficients. The model is simple enough to be calibrated to observations since 1850. The model is used to project emissions until 2100. Best-guess carbon dioxide emissions are in the middle of the IPCC SRES scenarios, but incomes and energy intensities are on the high side, while carbon intensities are on the low side. The confidence interval suggests that the SRES scenarios do not span the range of non-implausible futures. Although the model can be calibrated to reflect structural changes in the economy, it cannot anticipate such changes. The data poorly constrain crucial scenario elements, particularly energy prices. This suggests that the range of future emissions is wider still. (author)

[en] The economic impact of climate change is usually measured as the extent to which the climate of a given period affects social welfare in that period. This static approach ignores the dynamic effects through which climate change may affect economic growth and hence future welfare. In this paper we take a closer look at these dynamic effects, in particular saving and capital accumulation. With a constant savings rate, a lower output due to climate change will lead to a proportionate reduction in investment which in turn will depress future production (capital accumulation effect) and, in almost all cases, future consumption per capita. If the savings rate is endogenous, forward looking agents would change their savings behavior to accommodate the impact of future climate change. This suppresses growth prospects in absolute and per capita terms (savings effect). In an endogenous growth context, these two effects may be exacerbated through changes in labour productivity and the rate of technical progress. Simulations using a simple climate-economy model suggest that the capital accumulation effect is important, especially if technological change is endogenous, and may be larger than the direct impact of climate change. The savings effect is less pronounced. The dynamic effects are more important, relative to the direct effects, if climate change impacts are moderate overall. This suggests that they are more of a concern in developed countries, which are believed to be less vulnerable to climate change. The magnitude of dynamic effects is not sensitive to the choice of discount rate