Gas Stripping of Dwarf Galaxies in Clusters of Galaxies

Many clusters of galaxies contain an appreciable amount of hot gas, the intracluster medium. As a consequence, gas will be stripped from galaxies that move through the inter cluster medium, if the ram pressure exceeds the internal gravitational force. We study the interaction between the intracluster medium and an extended gas component of dwarf galaxies confined by a surrounding cold dark matter halo analytically and numerically, using axisymmetric two-dimensional hydrodynamical simulations at high resolution. The results show that the gas within the dark matter halo is totally stripped in a typical galactic cluster. The process of ram pressure stripping therefore must have played an important role during the chemo-dynamical evolution of dwarf galaxies in galactic clusters. Our results predict that most of the chemical evolution of dwarf galaxies must have occurred at high redshift, before the virialized cluster had formed.Comment: 9 pages, 6 figures; accepted for publication in Ap

Market power and hot air in international emissions trading: the impacts of US withdrawal from the Kyoto Protocol

Ten years after the initial Climate Change Convention from Rio in 1992 the industrialized world is finally likely to ratify the Kyoto Protocol, which will impose legally binding greenhouse gas emission reductions on the developed world. However, the Kyoto Protocol will enter into force without the USA, which withdrew under President Bush in March 2001. Accounting for hot air and market power of the Former Soviet Union on emission permit markets, it is shown that US withdrawal has important consequences on environmental effectiveness, compliance costs, and excess costs of market power under the Kyoto Protocol. Non-compliance of the USA implies a dramatic decrease in environmental effectiveness as well as compliance costs of OECD countries whereas the Former Soviet Union and transitional economies in Eastern Europe suffer from a huge decline in permit sales revenues. Excess costs of market power in permit trade increase in relative terms, but decline substantially in absolute terms due to US withdrawal. Policy options are quantified to bypass the problems of hot air and market power through compensation mechanisms.

Efficiency Gains from "What"-Flexibility in Climate Policy An Integrated CGE Assessment

We investigate the importance of ÒwhatÓ-flexibility on top of ÒwhereÓ- and ÒwhenÓ-flexibility for alternative emission control schemes that prescribe long-term temperature targets and eventually impose additional constraints on the rate of temperature change. We find that ÒwhatÓ-flexibility substantially reduces the economic adjustment costs. When comparing policies that simply involve long-term temperature targets against more stringent strategies with constraints on the rate of temperature increase, it turns out that the latter involve much higher costs. The cost difference may be interpreted as additional insurance payments if climate damages should not only depend on absolute temperature change but also on the rate of temperature change.