International audienceThe Cancun conference decided to establish a Climate Green Fund (CGF) to help developing countries align their development policies with the long-term UNFCCC objectives. This paper clarifies the links between the two underlying motives: the first, technical in nature, is the necessity to redirect the infrastructure instruments in these countries (energy, transportation, building, material transformation industry) to avoid lock-in in carbon-intensive pathways in the likely absence of a significant world carbon price in the coming decade; the second, political in nature, is the interpretation of the CGF as a practical translation of the notion of the common but differentiated responsibility principle, since the funds are expected to come from Annex 1 countries. This paper shows why this latter perspective might generate some distrust given the orders of magnitude of funds to be levied in Annex 1 countries especially in the context of the financial crisis and major constraints on public budgets. It then explores the basic principles around which it is possible to minimize these risks by upgrading climate finance in the broader context of the evolution of the financial and monetary systems. After exploring how such links could help make climate policies that contribute to reducing some of the imbalances caused by economic globalization by reorienting world savings and reducing investment uncertainty, it sketches how this perspective might be palatable for the OECD, the major emerging economies and fossil fuel exporters. © 2015, Springer Science+Business Media Dordrecht

This paper aims at providing a consistent framework to appraise alternative modeling choices that have driven the so-called "when flexibility" controversy since the early 1990s dealing with the optimal timing of mitigation efforts and the Social Cost of Carbon (SCC).The literature has emphasized the critical impact of modeling structures on the optimal climate policy. But, to our knowledge, there has been no contribution trying to estimate the comparative impact of modeling structures within a unified framework. In this paper, we use the Integrated Assessment Model (IAM) RESPONSE to bridge this gap and investigate the structural modeling drivers of differences in climate policy recommendations.RESPONSE is both sufficiently compact to be easily tractable and detailed enough to capture a wide array of modeling choices. Here, we restrict the analysis to the following emblematic modeling choices: the forms of the damage function (quadratic vs. sigmoid) and the abatement cost (with or without inertia), the treatment of uncertainty, and the decision framework (one-shot vs. sequential).We define an original methodology based on an equivalence criterion to carry out a sensitivity analysis over modeling structures in order to estimate their relative impact on two output variables: the optimal SCC and abatement trajectories. This allows us to exhibit three key findings: (i) IAMs with a quadratic damage function are insensitive to changes of other features of the modeling structure, (ii) IAMs involving a non-convex damage function entail contrasting climate strategies, (iii) Precautionary behaviours can only come up in IAMs with non-convexities in damages.

International audienceThis paper explores links between global financial imbalances and tensions around reserve currency along with climate change. Currently, risky levels of private and public debts coexist with vast amounts of savings that "do not know where to go." Long-term climate-oriented financial products could enhance investors' confidence in low-carbon projects (LCP) and channel to them large amounts of private savings. The paper outlines a financial architecture, the cornerstone of which is an agreement on the Social Cost of Carbon (SCC) integrated into a project's appraisal and acting as a surrogate for a carbon price. This SCC would be the value of carbon certificates issued by the government and delivered to banks to issue credit facilities reducing the risk-adjusted costs of LCPs. These carbon certificates could be gradually transformed into legal reserve assets of the banks after verification of the reality of the projects. Finally, the paper considers whether such certificates would be recognized as genuine international reserve assets, backed by the rising value of carbon over time. It shows how emerging countries could then diversify their foreign exchange reserves through an asset based on the international recognition of climate as a global public good

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SummaryGiven disparate beliefs about economic growth, technical change and damage caused by climate change, this paper starts with the seeming impossibility of determining a unique time profile of the social costs of carbon as a benchmark for climate negotiations and for infrastructure decisions that need to be made now in the absence of an inclusive international accord on climate policies. The paper demonstrates that determining a workable range of the social costs of carbon is however possible in a sequential decisionmaking framework that permits revising initial decisions in the light of new information. To do so, the paper exploits the results of a stochastic optimal control model run for more than 2000 scenarios that represent the set of beliefs presented about key uncertain parameters in the literature. The paper provides a heuristic mapping of the climate debate in the form of six "clubs of opinions" and shows the possibility of determining a range of social costs of carbon that might permit a compromise between the maximum range of "clubs" and those most likely to emerge in the future. Abstract Given disparate beliefs about economic growth, technical change and damage caused by climate change, this paper starts with the seeming impossibility of determining a unique time profile of the social costs of carbon as a benchmark for climate negotiations and for infrastructure decisions that need to be made now in the absence of an inclusive international accord on climate policies. The paper demonstrates that determining a workable range of the social costs of carbon is however possible in a sequential decision-making framework that permits revising initial decisions in the light of new information. To do so, the paper exploits the results of a stochastic optimal control model run for more than 2000 scenarios that represent the set of beliefs presented about key uncertain parameters in the literature. The paper provides a heuristic mapping of the climate debate in the form of six "clubs of opinions" and shows the possibility of determining a range of social costs of carbon that might permit a compromise between the maximum range of "clubs" and those most likely to emerge in the future.