Deconstructing the climate change response of the Northern Hemisphere wintertime storm tracks

There are large uncertainties in the circulation response of the atmosphere to climate change. One manifestation of this is the substantial spread in projections for the extratropical storm tracks made by different state-of-the-art climate models. In this study we perform a series of sensitivity experiments, with the atmosphere component of a single climate model, in order to identify the causes of the differences between storm track responses in different models. In particular, the Northern Hemisphere wintertime storm tracks in the CMIP3 multi-model ensemble are considered. A number of potential physical drivers of storm track change are identified and their influence on the storm tracks is assessed. The experimental design aims to perturb the different physical drivers independently, by magnitudes representative of the range of values present in the CMIP3 model runs, and this is achieved via perturbations to the sea surface temperature and the sea-ice concentration forcing fields. We ask the question: can the spread of projections for the extratropical storm tracks present in the CMIP3 models be accounted for in a simple way by any of the identified drivers? The results suggest that, whilst the changes in the upper-tropospheric equator-to-pole temperature difference have an influence on the storm track response to climate change, the large spread of projections for the extratropical storm track present in the northern North Atlantic in particular is more strongly associated with changes in the lower-tropospheric equator-to-pole temperature difference.

The Long Game: Hamas, The IRA, and the Politics of Radicalization in Palestine and Northern Ireland

The value of a comparative study of the two conflicts stems from a remarkable similarity in the structural organization of political violence by its most influential practitioners: the IRA and Hamas. At the core, I have merely tried my best to approach a beguiling question in a fresh, dynamic way. The stultifying discourse of conflict that serves as lingua franca for the Israeli‐Palestinian issue has largely reduced strategic debate to how best the conflict can be managed – not ended. Prime Minister Benjamin Netanyahu’s focus on “economic peace” and unwillingness to commit to a two‐state solution – the consensus that has governed peacemaking for decades – belies such thinking. The Clinton Administration’s cadre of Mideast negotiators operated amidst the most rapid institutionalization of Palestinian democracy in history ‐ yet remained obsessed with Israeli‐Arab “confidence‐building” measures, doing little to legitimize the gains of Oslo. So long as Palestinians continue to view the creation of Israel as “al‐Nakba” – the catastrophe – whilst successive Israeli governments refuse to grant their aspirations any legitimacy, there can be no progress. Peace requires empathy, a substantial compromise in the context of internecine conflict. The “long war” both conflicts have become mandates an equally expansive, broad‐based and labor‐intensive approach – a demanding process that can only be called The Long Game.