AN INTRODUCTION TO CLIMATE CHANGE ECONOMICS AND POLICY, F.R. Fitzroy and E. Papyrakis, Earthscan Ltd, London, 2009, 214 pages, ISBN 978-1-844-07809-7

Anyone trying to sort out the seemingly inexplicable machinations that went on in Copenhagen should read ‘An introduction to climate Change Economics and Policy’. Which is to say this book is an excellent way of updating your knowledge of the fast changing science, economics and policy on climate change issues and a useful window into how academics are approaching the issue. This exhortation is directed to students and members of the public and less so to those who are in the field of climate change.

The Structural and Kinematic Evolution of Central Star Clusters in Dwarf Galaxies and Their Dependence on Dark Matter Halo Profiles

Through a suite of direct N-body simulations, we explore how the structural and kinematic evolution of a star cluster located at the center of a dwarf galaxy is affected by the shape of its host's dark matter density profile. The stronger central tidal fields of cuspier halos minimize the cluster's ability to expand in response to mass loss due to stellar evolution during its early evolutionary stages and during its subsequent long-term evolution driven by two-body relaxation. Hence clusters evolving in cuspier dark matter halos are characterized by more compact sizes, higher velocity dispersions and remain approximately isotropic at all clustercentric distances. Conversely, clusters in cored halos can expand more and develop a velocity distribution profile that becomes increasingly radially anisotropic at larger clustercentric distances. Finally, the larger velocity dispersion of clusters evolving in cuspier dark matter profiles results in them having longer relaxation times. Hence clusters in cuspy galaxies relax at a slower rate and, consequently, they are both less mass segregated and farther from complete energy equipartition than cluster's in cored galaxies. Application of this work to observations allows for star clusters to be used as tools to measure the distribution of dark matter in dwarf galaxies and to distinguish isolated star clusters from ultra-faint dwarf galaxies.Comment: 8 pages, 7 figures, Accepted for publication in MNRA

Exploring Preconditions for Effective Global Responses to Climate Change

The global response to climate change depends on you… and everyone else. The decisions we make, for better or worse, contribute to the global response. This study explores decision making, climate change signals and responses, actors and interests, and the “conditions” under which we might limit climate change and related impacts. Twenty-seven experts from around the world were asked to provide scenarios where the global response succeeds or fails to limit climate change and related impacts (i.e. the UNFCCC objective). From their responses, 175 scenarios were compiled forming a “searchable sample of possible futures”. Themes included social change and behaviour, political will and policy, business and economic activity. For these themes, multiple “pathways” were mapped. The study focused on pathways towards effective global responses (i.e. fulfilling the UNFCCC objective) and understanding the most important elements of the response system. The study finds there is a “crisis of response” that risks becoming a “crisis of impacts”. The signal that drives effective responses (i.e. impacts on people, property and livelihoods) was undetectable, is detectable now, and is rapidly strengthening. As such, timely global responses at scale are essential. Other preconditions include a mix of ambition and serendipity. From the analysis of effective response scenarios, serendipitous preconditions include the scale of climate change and related impacts being limited and reversible meanwhile unexpected events help limit climate change or related impacts. Ambition driven preconditions include global responses being timely with adaptation, mitigation and atmospheric GHG removals at scale, and having contingencies available in case of extreme climate change or other unexpected events. The transformative scale of required responses means social permissions and leadership are essential, as are coalitions of actors with the capacity to apply technologies and practices (policies included) and power to ensure each of us are contributing towards effective global responses