Is peak oil good news or bad news? Much depends on your perspective. The gloomier prognostications about peak oil – living in a world where oil supplies are limited and expensive – suggest that it will be a bigger problem than climate change, and arrive sooner. On the other hand, if we’re forced to cut back on our usage of oil and gas as fuel for energy and transport, we might have a better chance of stabilising atmospheric carbon dioxide at levels low enough to limit the damage from climate change. The IPCC’s high-end scenarios typically assume that there’s plenty of fossil fuel – coal, oil and gas – to get us to double pre-industrial concentrations and beyond. What happens if the oil runs out?