The document discusses the concept of peak oil and its implications. It begins by defining peak oil as the point when global oil production reaches its maximum rate and begins declining. It then discusses how increased global urbanization and modernization will drive big increases in energy demand, particularly fossil fuels. The document also explores the history of cities and their energy intensity. It notes that disruptions to the global oil supply could have major impacts without sufficient mitigation efforts well in advance. Potential solutions discussed include transition towns and ecolocalization efforts, but these are small and tend not to address large cities or mass populations. The document concludes by emphasizing the need to take the threats of peak oil seriously and plan proactively.