At the heart of contemporary capitalism lies the concept of economic growth. So one can’t assess the compatibility of sustainable development and capitalism without first getting to grips with growth. This remains a critical debate, though much less current than it was during the 1970s – perhaps because the laws of thermodynamics have proved such indigestible fare for modern politicians! But today’s critique of growth is no anti-growth or zero-growth diatribe: economic growth can still be great, and billions of people all around the world still need a lot more of it. But what kind of growth? For whom? Within what limits? And measured against what kind of benchmarks? To shed light on these questions, this chapter considers the so-called ‘peak oil debate’: how soon will the extraction of oil and gas peak in terms of their contribution to global energy supplies? A lot rests on the answer to this question, given the critical role that access to reliable and relatively cheap oil and gas has played in driving our growth economies over the last 50 years.