Equity weighting and the marginal damage costs of climate change

Climate change would impact different countries differently, and different countries have different levels of development. Equity-weighted estimates of the (marginal) impact of greenhouse gas emissions reflect these differences. Equity-weighted estimates of the marginal damage cost of carbon dioxide emissions are substantially higher than estimates without equity-weights; equity-weights may also change the sign of the social cost estimates. Equity weights need to be normalised. Our estimates differ by two orders of magnitude depending on the region of normalisation. A discounting error of equity weighted social cost of carbon estimates in earlier work (Tol, Energy Journal, 1999), led to an error of a factor two. Equity-weighted estimates are sensitive to the resolution of the impact estimates. Depending on the assumed intra-regional income distribution, estimates may be more than twice as high if national rather than regional impacts are aggregated. The assumed scenario is important too, not only because different scenarios have different emissions and hence warming, but also because different scenarios have different income differences, different growth rates, and different vulnerabilities. Because of this, variations in the assumed inequity aversion have little effect on the marginal damage cost in some scenarios, and a large effect in other scenarios.marginal damage costs, climate change, equity

Equity Weighting and the Marginal Damage Costs of Climate Change

Climate change would impact different countries differently, and different countries have different levels of development. Equity-weighted estimates of the (marginal) impact of greenhouse gas emissions reflect these differences. Equity-weighted estimates of the marginal damage cost of carbon dioxide emissions are substantially higher than estimates without equity-weights; equity-weights may also change the sign of the social cost estimates. Equity weights need to be normalised. Our estimates differ by two orders of magnitude depending on the region of normalisation. A discounting error of equity weighted social cost of carbon estimates in earlier work (Tol, Energy Journal, 1999), led to an error of a factor two. Equity-weighted estimates are sensitive to the resolution of the impact estimates. Depending on the assumed intra-regional income distribution, estimates may be more than twice as high if national rather than regional impacts are aggregated. The assumed scenario is important too, not only because different scenarios have different emissions and hence warming, but also because different scenarios have different income differences, different growth rates, and different vulnerabilities. Because of this, variations in the assumed inequity aversion have little effect on the marginal damage cost in some scenarios, and a large effect in other scenarios.Marginal Damage Costs, Climate Change, Equity

Social Discounting Under Uncertainty: A cross-country comparison

Recent research suggests that social cost-benefit analysis should be con- ducted with a declining discount rate. For instance, Newell and Pizer [23] show that the U.S. certainty-equivalent discount rate declines through time, using a simple autoregressive model of U.S. interest rates. This paper extends that line of research, estimating both autoregressive and regime-switching models of real interest rates to determine certainty- equivalent discount rates in Australia, Canada, Germany and the United Kingdom. It is found that the regime-switching model is a better model of past interest rate behavior for all four countries. This model tends to produce a more rapid decline in certainty-equivalent discount rates. The paper provides applications to the economics of climate change and nuclear power.discounting, uncertainty, regime-switching models, climate change policy, nuclear power

Auctioning of EU ETS Phase II allowances: how and why?

The European Directive on the EU ETS allows governments to auction up to 10% of the allowances issued in phase II 2008-2012, without constraints being specified thereafter. This article reviews and extends the long-standing debate about auctioning, in which economists have generally supported and industries opposed a greater use of auctioning. The article clarifies the key issues by reviewing six `traditional' considerations, examines several credible options for auction design, and then proposes some new issues relevant to auctioning. It is concluded that greater auctioning in aggregate need not increase adverse competitiveness impacts, and could in some respects alleviate them, particularly by supporting border-tax adjustments. Auctioning within the 10% limit might also be used to dampen price volatility during 2008-2012 and, in subsequent periods, it offers the prospect of supporting a long-term price signal to aid investor confidence. The former is only possible, however, if Member States are willing to coordinate their decision-making (though not revenue-raising) powers in defining and implementing the intended pricing mechanisms

Emissions Trading with Profit-Neutral Permit Allocations

This paper examines the operation of an emissions trading scheme (ETS) in a Cournot oligopoly. We study the impact of the ETS on industry output, price, costs, emissions, and profits. In particular, we develop formulae for the number of emissions permits that have to be freely allocated to firms in order to neutralize any adverse impact the ETS may have on profits. These formulae tell us that the profit impact of the ETS is usually limited. Indeed, under quite general conditions, industry profits are preserved so long as firms are freely allocated a fraction of their total demand for permits, with this fraction being lower than the industry's Herfindahl index.Emissions trading, permit allocation, profit-neutrality, cost pass-through, abatement, grandfathering

CHECKING THE PRICE TAG ON CATASTROPHE: THE SOCIAL COST OF CARBON UNDER NON-LINEAR CLIMATE RESPONSE

Research into the social cost of carbon emissions — the marginal social damage from a ton of emitted carbon — has tended to focus on “best guess” scenarios. Such scenarios generally ignore the potential for low-probability, high-damage events, which are critically important to determining optimal climate policy. This paper uses the FUND integrated assessment model to investigate the influence of three types of non-linear climate responses on the social cost of carbon: the collapse of the thermohaline circulation; the dissociation of oceanic methane hydrates; and climate sensitivities above “best guess” levels. We find that incorporating these impacts can increase the social cost of carbon by a factor of 20. Furthermore, our results suggest that the exclusive focus on thermohaline circulation collapse in the non-linear climate response literature is unwarranted, because other potential non-linear climate responses appear to be significantly more costly.climate change, catastrophe, non-linearity, impacts

Multiscale design for system-wide peer-to-peer energy trading

The integration of renewable generation and the electrification of heating and transportation are critical for the sustainable energy transition toward net-zero greenhouse gas emissions. These changes require the large-scale adoption of distributed energy resources (DERs). Peer-to-peer (P2P) energy trading has gained attention as a new approach for incentivizing the uptake and coordination of DERs, with advantages for computational scalability, prosumer autonomy, and market competitiveness. However, major unresolved challenges remain for scaling out P2P trading, including enforcing network constraints, managing uncertainty, and mediating transmission and distribution conflicts. Here, we propose a novel multiscale design framework for P2P trading, with inter-platform coordination mechanisms to align local transactions with system-level requirements, and analytical tools to enhance long-term planning and investment decisions by accounting for forecast real-time operation. By integrating P2P trading into planning and operation across spatial and temporal scales, the adoption of large-scale DERs is tenable and can create economic, environmental, and social co-benefits