This would be in addition to a much less theoretical short-term cooling caused by smoke from the fires and dust thrown into the atmosphere by the impact.

ECONOMIST: Mass extinctions

And of course, in addition to our plans to reduce the long-term demands on the state by fixing our broken society and to improve the productivity of the state by reforming public services we want to save money straight away by cutting out government waste and outdated programmes.

BBC: In full: Cameron's economy speech

In addition to that set of challenges, we also face a long-term fiscal gap, which is driven primarily by health care costs.

WHITEHOUSE: Detailing the FY2011 Budget