Brown Tech: Top Down Constriction Slow energy decline rates, severe climate change symptoms The Brown Tech world is one in which the production of oil declines after a peak 2005-2010 at about 2% per annum and the subsequent peak and decline of natural gas is also relatively gentle, but the severity of global warming symptoms is at the extreme end of current mainstream scientific predictions. In this scenario strong, even aggressive, national policies and actions prevail to address both the threats and the opportunities from energy peak and climatic change. The political system could be described as Corporatist or Fascist (which Mussolini described as a merger of state and corporate power). Green Tech: Distributed Powerdown Slow energy decline rates, mild climate change symptoms. The Green Tech scenario is the most benign, in that adverse climate changes are at the low end of projections. Oil and gas production declines slowly as in the Brown Tech future, so the sense of chaos and crisis is more muted without major economic collapse or conflict. This allows resources to flow to a greater diversity of responses at the global, national, city, community and personal level. In some already densely populated poor countries, conditions worsen. Earth Stewardship: Bottom Up Rebuild Rapid energy decline rates, mild climate change symptoms In this scenario the decline in oil production after a peak in total liquids production before 2010 is at the extreme end of authoritative predictions (about 10%)49  and is followed by an even faster decline in gas production plus a simultaneous peak in coal production. The shock to the world’s fragile financial systems is overwhelming, resulting in severe economic depression and perhaps some further short, sharp resource wars. Lifeboats: Civilization Triage Rapid energy decline rates, severe climate change symptoms. In this scenario, supplies of high quality fossil fuels decline rapidly, the economy fails and human contributions to global warming collapse but lag effects and positive feedbacks in the climate system continue to drive an acceleration of global warming. As of 2007, an increasing number of scientists believe it may already be too late to avoid catastrophic climate change.50  In the Lifeboat scenario the adverse symptoms of the Brown Tech and Earth Steward scenarios combine to force a progressive collapse in most forms of economy and social organisation. Local wars, including use of nuclear weapons accelerate collapse in some areas but the failure of national systems of power prevent global warfare. Successive waves of famine and disease breakdown social and economic capacity on a larger scale than the Black Death in medieval Europe leading to a halving of global population in a few decades.Personally, I’m pulling for the Green Tech future. Not only is it the most benign of the four scenarios, but, for an eco-geek like me, it also has the coolest toys. Check out David’s web site for more. 
As announced by Eat the Suburbs!, David Holmgren , author of Permaculture: Principles and Pathways Beyond Sustainability , has launched Future Scenarios at www.futurescenarios.org . The site is a long essay from David that has been broken down into informative micro-chapters, each detailing what David sees as a possible future. In the essay, Holmgren has outlined the following four future scenarios with thoughtful analysis and evidence for the possibility of each outcome.