Climate Agreements and Technology Policy

We study climate policy when there are technology spillovers within and across countries, and the technology externalities within each country are corrected through a domestic subsidy of R&D investments. We compare the properties of international climate agreements when the inter-country externalities from R&D are not regulated through the climate agreement. With an international agreement controlling abatements directly through emission quotas, the equilibrium R&D subsidy is lower that the socially optimal subsidy. The equilibrium subsidy is even lower if the climate agreement does not specify emission levels directly, but instead imposes a common carbon tax. Social costs are higher under a tax agreement than under a quota agreement. Moreover, for a reasonable assumption on the abatement cost function, R&D investments and abatement levels are lower under a tax agreement than under a quota agreement. Total emissions may be higher or lower in a second-best optimal quota agreement than in the first-best optimum.Climate policy, International environmental agreements, R&D Policy, Technology spillovers

Endogenous Technology and Tradable Emission Quotas

We study an international climate agreement that assigns emission quotas to each participating country. Unlike the simplest models in the literature, we assume that abatement costs are affected by R&D activities undertaken in all firms in all countries, i.e. abatement technologies are endogenous. In line with the Kyoto agreement we assume that the international climate agreement does not include R&D policies. We show that for a second-best agreement, marginal costs of abatement should exceed the Pigovian level. Moreover, marginal costs of abatement differ across countries in the second-best quota agreement with heterogeneous countries. In other words, the second-best outcome cannot be achieved if emission quotas are tradable.Climate Policy, International Climate Agreements, Emission Quotas, Technology Spillovers

Climate Policy under Technology Spillovers

Technological development is likely to play an important role in curbing growth in greenhouse gas emissions. It is therefore important to incorporate factors influencing technological change in climate policy analyses. This paper studies climate policy when there are technology spillovers between countries, and there is no instrument that (directly) corrects for these externalities. The lack of an appropriate instrument reflects that R&D expenditures in a country are difficult to verify by other countries. We show that without an international agreement, the non-cooperative outcome will have too much emissions and too little R&D expenditures compared with the social optimum. While the non-cooperative equilibrium depends on whether countries use tradable quotas or carbon taxes as their domestic instruments for controlling emissions, all countries are better off in the tax case than in the quota case. Next we study two types of international climate agreements with full participation. One is a Kyoto type of agreement where each country is assigned a specific number of internationally tradable quotas. In the second type of agreement a common carbon tax should be used domestically in all countries. We show that none of the cases satisfy the conditions for the social optimum. Even if the total number of quotas is set so that the quota price is equal to the Pigovian level, R&D investments will be lower than what is socially optimal in the Kyoto case, whereas with a harmonized domestic carbon tax R&D expenditures could even be too high. Finally we examine the case in which there is an incomplete agreement, i.e. some countries have not signed the agreement. We demonstrate that there is virtually no difference between this case and the case of full cooperation.Climate policy, international environmental agreements, R&D, technology spillovers

International Cooperation on Climate-Friendly Technologies

We examine international cooperation on technological development as a supplement to, or an alternative to, international cooperation on emission reductions. R&D should be increased beyond the non-cooperative level if (i) the technology level in one country is positively affected by R&D in other countries, (ii) the domestic carbon tax is lower than the Pigovian level, or (iii) the domestic carbon tax is set directly through an international tax agreement. A second-best technology agreement has higher R&D, higher emissions, or both compared with the first-best-outcome. The second-best subsidy always exceeds the subsidy under no international R&D cooperation. Further, when the price of carbon is the same in the second-best technology agreement and in the case without R&D cooperation, welfare is highest, R&D is highest and emissions are lowest in the second-best R&D agreement.climate policy, international climate agreements, R&D policy, technology spillovers

Modelled and measured strain in mascon basins on the moon

The close association of wrinkle ridges and grabens with mascon basins on the Moon has suggested that the responsible compression and extension resulted from basin subsidence and peripheral flexing of the lithosphere. The distribution of grabens and wrinkle ridges associated with mascon basins has been further used along with elastic plate bending models to constrain the thickness of the lithosphere at the time of their formation. Kinematic models for basin subsidence have also been developed and compared with strains inferred from grabens and wrinkle ridges. Note that kinematic models may be preferable to dynamic models because the strain associated with tectonic features can be compared directly with model predictions and because fewer assumptions are required for their calculations, such as perfect elasticity and specific values of the elastic moduli. Also, if the results from kinematic models compare favorably with the strain estimated across the tectonic features on the Moon, then a global strain field may not be necessary. Herein, the strain inferred for wrinkle ridges and grabens was compared to that calculated from a simple kinematic subsidence model for mascon basins on the Moon

Physiographic constraints on the origin of lunar wrinkle ridges

Wrinkle ridges are linear asymmetric topographic highs with considerable morphologic complexity that are commonly found on the lunar maria and the smooth plains of Mars and Mercury. The origin of planetary wrinkle ridges has been a much argued and debated topic. Early ideas suggested that wrinkle ridges resulted from volcanic intrusion and extrusion of high viscosity lavas; these early ideas were countered with suggestions that wrinkle ridges formed from tectonic processes involving folding and faulting. Combined volcanic and tectonic mechanisms have also been suggested. The identification and analysis of a number of morphologically similar structures on the earth has helped in the recent interpretation of wrinkle ridges as thrust faults that deform surface rocks. Nevertheless, there remains the uncertainty of the dominant role of thrusting versus folding in the formation of planetary wrinkle ridges. Presented is a detailed physiographic analysis of lunar wrinkle ridges in an effort to help distinguish the dominant deformation mechanism. Results agree with the findings of the earth analog study and support the hypothesis that wrinkle ridges form from thrust faults that deform surface rocks

Climate Policy without Commitment

Climate mitigation policy should be imposed over a long period, and spur development of new technologies in order to make stabilization of green house gas concentrations economically feasible. The government may announce current and future policy packages that stimulate current R&D in climate-friendly technologies. However, once climate-friendly technologies have been developed, the government may have no incentive to implement the pre-announced future policies, that is, there may be a time inconsistency problem. We show that if the government can optimally subsidize R&D today, there is no time inconsistency problem. Thus, lack of commitment is not an argument for higher current R&D subsidies. If the offered R&D subsidy is lower than the optimal subsidy, the current (sub-game perfect) climate tax should exceed the first-best climate tax.time consistency, carbon tax, climate policy, R&D, endogenous technological change

MEVTV Workshop on Tectonic Features on Mars

The state of knowledge of tectonic features on Mars was determined and kinematic and mechanical models were assessed for their origin. Three sessions were held: wrinkle ridges and compressional structure; strike-slip faults; and extensional structures. Each session began with an overview of the features under discussion. In the case of wrinkle ridges and extensional structures, the overview was followed by keynote addresses by specialists working on similar structures on the Earth. The first session of the workshop focused on the controversy over the relative importance of folding, faulting, and intrusive volcanism in the origin of wrinkle ridges. The session ended with discussions of the origin of compressional flank structures associated with Martian volcanoes and the relationship between the volcanic complexes and the inferred regional stress field. The second day of the workshop began with the presentation and discussion of evidence for strike-slip faults on Mars at various scales. In the last session, the discussion of extensional structures ranged from the origin of grabens, tension cracks, and pit-crater chains to the origin of Valles Marineris canyons. Shear and tensile modes of brittle failure in the formation of extensional features and the role of these failure modes in the formation of pit-crater chains and the canyons of Valles Marineris were debated. The relationship of extensional features to other surface processes, such as carbonate dissolution (karst) were also discussed

Failure strength of icy lithospheres

Lithospheric strengths derived from friction on pre-existing fractures and ductile flow laws show that the tensile strength of intact ice under applicable conditions is actually an order of magnitude stronger than widely assumed. It is demonstrated that this strength is everywhere greater than that required to initiate frictional sliding on pre-existing fractures and faults. Because the tensile strength of intact ice increases markedly with confining pressure, it actually exceeds the frictional strength at all depths. Thus, icy lithospheres will fail by frictional slip along pre-existing fractures at yeild stresses greater than previously assumed rather than opening tensile cracks in intact ice

Rifting on Venus: Implications for lithospheric structure

Lithospheric strength envelopes on Venus are reviewed and their implications for large scale rifting are discussed. Their relationship to crustal thicnesses and thermal gradients are explored. Also considered are the implications of a theory for rift formation