The parameters space of the spin-orbit problem I. Normally hyperbolic invariant circles

In this paper we start a global study of the parameter space (dissipation, perturbation, frequency) of the dissipative spin-orbit problem in Celestial Mechanics with the aim of delimiting regions where the dynamics, or at least some of its important features, is determined. This is done via a study of the corresponding family of time $2\pi$-maps. In the same spirit as Chenciner in his 1895 article on bifurcations of elliptic fixed points, we are at first interested in delimiting regions where the normal hyperbolicity is sufficiently important to guarantee the persistence of an invariant attractive (resp. repulsive) circle under perturbation. As a tool, we use an analogue for diffeomorphisms in this family of R\"ussmann's translated curve theorem in analytic category.Comment: 21 pages, 5 figure

A Tale of Two Countries: Emissions Scenarios for China and India

The aim of the paper is to present evidence that China and India are, and will remain, two very different actors in international negotiations to control global warming. We base our conclusions on historical data and on scenarios until 2050. The Business-as-Usual scenario (BaU) is compared to four Emissions Tax scenarios to draw insights on major transformations in energy use and in energy supply and to assess the possible contribution of China and India to a future international climate architecture. We study whether or not the Copenhagen intensity targets require more action than the BaU scenario and we assess whether the emissions reductions induced by the four tax scenarios are compatible with the G8 and MEF pledge to reduce global emissions by 50% in 2050.Climate Change, China, India, Energy Efficiency, Energy and Development

The Optimal Climate Policy Portfolio when Knowledge Spills Across Sectors

This paper studies the implications for climate policy of the interactions between environmental and knowledge externalities. Using a numerical analysis performed with the hybrid integrated assessment model WITCH, extended to include mutual spillovers between the energy and the non-energy sector, we show that the combination between environmental and knowledge externalities provides a strong rationale for implementing a portfolio of policies for both emissions reduction and the internalisation of knowledge externalities. Moreover, we show that implementing technology policy as a substitute for stabilisation policy is likely to increase global emissions.Technical Change, Climate Change, Development, Innovation, Spillovers

Beyond Copenhagen: A Realistic Climate Policy in a Fragmented World

We propose a realistic approach to climate policy based on the Copenhagen Agreement to reduce Greenhouse Gases (GHGs) emissions. We assess by how much the non-binding, although official, commitments to reduce emissions made in Copenhagen will affect the level of world GHGs emissions in 2020. Our estimates are based on official communications to the UNFCCC, on historic data and on the Business-as-Usual scenario of the WITCH model. We are not interested in estimating the gap between the expected level of emissions and what would be needed to achieve the 2°C target. Nor do we attempt to calculate the 2100 temperature level implied by the Copenhagen pledges. We believe these two exercises are subject to high uncertainty and would not improve the current state of negotiations. Rather, we take stock of the present politically achievable level of commitment and suggest an effective way to push forward the climate policy agenda. The focus is on what can be done rather than on what should be done. To this end, we estimate the potential of the financial provisions of the Copenhagen Agreement to sponsor mitigation effort in Non-Annex I countries. Using scenarios produced with the WITCH model, we show that lower commitment on domestic abatement measures can be compensated by devoting roughly 50% of the Copenhagen financial provisions in 2020 to mitigation in Non-Annex I countries. The policy implications of our results will be discussed.Kyoto Protocol, International Climate Agreements, Climate Policy, Clean Development Mechanism

A Numerical Analysis of Optimal Extraction and Trade of Oil under Climate Policy

We introduce endogenous investments for increasing conventional and non-conventional oil extraction capacity in the integrated assessment model WITCH. The international price of oil emerges as the Nash equilibrium of a non-cooperative game. When carbon emissions are not constrained, oil is used throughout the century, with unconventional oil taking over conventional oil from mid-century onward. When carbon emissions are constrained, oil consumption drops dramatically and the oil price is lower than in the BaU. Unconventional oil is not extracted. Regional imbalances in the distribution of stabilisation costs are magnified and the oil-exporting countries bear, on average, costs three times larger than in previous estimates.Climate Policy, Integrated Assessment, Oil Production, Oil Revenues, Oil Trade

The Optimal Climate Policy Portfolio when Knowledge Spills across Sectors

This paper studies the implications for climate policy of the interactions between environmental and knowledge externalities. Using a numerical analysis performed with the hybrid integrated assessment model WITCH, extended to include mutual spillovers between the energy and the non-energy sector, we show that the combination between environmental and knowledge externalities provides a strong rationale for implementing a portfolio of policies for both emissions reduction and the internalisation of knowledge externalities. Moreover, we show that implementing technology policy as a substitute for stabilisation policy is likely to increase global emissions.technical change, climate change, development, innovation, spillovers

Banking Permits: Economic Efficiency and Distributional Effects

Most analyses of the Kyoto flexibility mechanisms focus on the cost effectiveness of “where” flexibility (e.g. by showing that mitigation costs are lower in a global permit market than in regional markets or in permit markets confined to Annex 1 countries). Less attention has been devoted to “when” flexibility, i.e. to the benefits of allowing emission permit traders to bank their permits for future use. In the model presented in this paper, banking of carbon allowances in a global permit market is fully endogenised, i.e. agents may decide to bank permits by taking into account their present and future needs and the present and future decisions of all the other agents. It is therefore possible to identify under what conditions traders find it optimal to bank permits, when banking is socially optimal, and what are the implications for present and future permit prices. We can also explain why the equilibrium rate of growth of permit prices is likely to be larger than the equilibrium interest rate. Most importantly, this paper analyses the efficiency and distributional consequences of allowing markets to optimally allocate emission permits across regions and over time. The welfare and distributional effects of an optimal intertemporal emission trading scheme are assessed for different initial allocation rules. Finally, the impact of banking on carbon emissions, technological progress, and optimal investment decisions is quantified and the incentives that banking provides to accelerate technological innovation and diffusion are also discussed. Among the many results, we show that not only does banking reduce abatement costs, but it also increases the amount of GHG emissions abated in the short-term. It should therefore belong to all emission trading schemes under construction.emission trading, banking

The WITCH Model. Structure, Baseline, Solutions

WITCH – World Induced Technical Change Hybrid – is a regionally disaggregated hard-link hybrid global model with a neoclassical optimal growth structure (top-down) and a detailed energy input component (bottom-up). The model endogenously accounts for technological change, both through learning curves that affect the prices of new vintages of capital and through R&D investments. The model features the main economic and environmental policies in each world region as the outcome of a dynamic game. WITCH belongs to the class of Integrated Assessment Models as it possesses a climate module that feeds climate changes back into the economy. Although the model’s main features are discussed elsewhere (Bosetti et al., 2006), here we provide a more thorough discussion of the model’s structure and baseline projections, to describe the model in greater detail. We report detailed information on the evolution of energy demand, technology and CO2 emissions. We also explain the procedure used to calibrate the model parameters. This report is therefore meant to provide effective support to those who intending to use the WITCH model or interpret its results.Climate Policy, Hybrid Modelling, Integrated Assessment, Technological Change