David Holmgren, one of the originators of the permaculture concept, has recently written what I believe is one of the best books on the societal implications of peak oil and climate change to be published over the last several years. His book “Future Scenarios, How Communities Can Adapt to Peak Oil and Climate Change” (Chelsea Green Publishing, 2008), is a concise, well-written exploration of a range of possible futures facing humanity given certain assumptions about the interplay between the key variables of peak oil and climate change over the next few decades. One of the most thought provoking and I believe useful observations he makes in the book is the distinction between energy descent and collapse, which I will relate shortly after exploring his main scenarios.

The author considers energy--and more importantly whether future energy supplies will likely increase, remain stable, or decrease--to be the most important variable in assessing potential futures. In the book, he first considers four meta-level energy-driven scenarios for the long-term future, these being ‘techno-explosion’, ‘techno-stability’, ‘energy descent’ and ‘collapse’. ‘Techno-explosion’ can be thought of as the science fiction future of continual growth made possible by energy breakthroughs such as nuclear fusion and free energy from the vacuum of space. Humanity is able to transcend the limits to growth on a finite planet through continual technological innovation and space colonization. The amount of energy available to mankind increases steadily over time, with no end in sight to available energy and the economic and population growth this makes possible. Though this scenario may have looked like the potential future when Arthur C. Clarke wrote the classic “2001, A Space Odyssey”, most policy makers now seem willing to concede that the odds of it coming to pass are vanishing more rapidly than the dwindling oil reserves of Mexico’s Canterell field.

In ‘Techno-stability’ he envisions “a seamless conversion from material growth based on depleting fossil energy to a steady-state in consumption of resources and population, if not economic activity.” This seems to be the scenario envisioned by politicians and corporations promoting the conversion to a ‘green economy’, yet who do not realize or acknowledge that no combination of renewable energy resources will enable industrial society to run as it has been running on fossil fuels, as repeatedly emphasized by James H. Kunstler. In Techno-stability the amount of energy available to humanity may fall a bit during the transition, but will stabilize thereafter allowing for a newer, greener business as usual economy. Later in the book, however, he acknowledges the “small problem of reforming the monetary system away from dependence on perpetual growth without inducing financial collapse”. Or, as Michael Ruppert puts it, “until you change the way money works, you change nothing”. Holmgren echoes the opinion of such researchers as Robert Hirsh in stating that a smooth transition away from an economy based on fossil fuels to one based on renewable energy is unlikely this late in the game without severe economic and geo-political crises. Hirsh, in a recent study prepared for the US Department of Energy, found that industrial societies will require at least a decade of intensive effort in advance of peak oil to avoid the hard landing of a severe economic downturn that results from the growing gap between supply and demand for liquid fuels. In light of this, it therefore appears increasingly unlikely that even techno-stability can be achieved.

This understanding leads the author to explore what he considers the most likely long-term future, ‘energy descent’. Energy descent “involves a reduction of economic activity, social complexity and population in some way as fossil fuels are depleted. The increasing reliance on renewable resources of lower energy density will change the structure of society to reflect that of pre-industrial societies”. He doesn’t see energy descent as a smooth process either, but as one that will be marked by crisis periods interspersed by temporary stable states, with the amount of energy available and societal complexity decreasing with each step down the ladder, until a new long-term steady state is achieved.

The author then further breaks down energy descent into four sub-scenarios based on how climate change / global warming and the post peak oil era might manifest over the next 10 – 30 years. The main variables he chooses are whether the near term impacts of global warming / climate change are severe or somewhat benign, and whether post-peak oil decline rates are high or low. He expresses this in graphic form in a chart that appears on page 60 of his book, reproduced below. Oil depletion appears on the X axis and global warming impacts on the Y axis. The four energy descent scenarios that emerge from this schema are ‘Brown-Tech’, ‘Green-Tech’, ‘Earth Steward’ and ‘Lifeboats’.

The ‘Brown-Tech’ scenario results from the combination of slow oil decline rates and the rapid onset of adverse climate impacts. There is a strong emphasis on providing liquid fuels from unconventional oil such as tar sands and coal as described in the Hirsh report. Strong national / corporatist governments provide centralized responses to the energy crisis, though unfortunately ones that exacerbate the release of greenhouse gases. Over time, this scenario devolves into the lifeboat scenario described below.

In ‘Green-Tech’, enabled by benign climate change and low post-peak oil decline rates, much emphasis is placed on developing renewable energy resources, especially wind and solar. The economy is robust enough that relatively large scale deployment of these renewable energy technologies is possible. A resurgence of local and regional economies helps the country power-down to the extent necessary to take advantage of the lower amounts of energy (compared to that available from fossil fuels) available from the larger scale solar and wind projects developed under this scenario. Holmgren believes that over time – decades perhaps – this scenario will evolve into the Earth Steward scenario as available energy continues its relentless decline.

In the ‘Earth Steward’ scenario, severe economic impacts from rapid oil decline – ten percent or more per year – bring about a complete collapse of the world monetary and financial system, thereby preventing the rapid, large scale deployment of renewable energy technologies as in ‘Green-Tech’. However, small scale deployment of these at the household and village level is a key component of the energy mix in this scenario. Climate change is relatively mild. This is a very agrarian scenario, with permaculture playing a large role in how food is produced. ‘Earth Steward’ appears to be similar to the ‘catabolic collapse’ scenario mapped out by John Michael Greer in his book “The Long Descent”. ‘Earth Steward’ perhaps best expresses the vision of long-term sustainability as envisioned by Permaculture and the Transition Towns movements.

The ‘Lifeboats’ scenario is the most challenging of the energy descent pathways. In this scenario, severe economic impacts from rapid oil decline combined with the severe rapid onset of climate change disruptions lead to a rapid decline in societal complexity and the ability to maintain large, centralized governments and institutions. Still, enough knowledge and technology makes it through this transition to allow civilization to continue in somewhat isolated pockets.

This contrasts with his discussion of total collapse which equates to total system failure without the restabilization possible in any of these energy descent scenarios. “The retention of cultural knowledge of the past combined with a moderately habitable environment allow new civilizations to emerge that build on at least some of the knowledge and lessons from ours.” Holmgren believes that “the all encompassing use of the term collapse is too broad a definition and inconsistent with our normal understanding of the term as a rapid and complete process.” I concur. ‘Future Scenarios’ provides a much more nuanced view of our near-term future than that envisioned by many writers and bloggers on the topics of peak oil and climate change. The frequent use of the term ‘collapse’ can lead one to believe that is too late for any effective action, though as Holmgren writes, that is far from the truth.

Will the near term future of energy descent fall neatly into one of David Holmgren’s four scenarios? That is perhaps unlikely, as many factors besides climate change and post peak oil decline rates will determine how society powers down over the next few decades.

It appears that government and corporate forces are moving the United States into a sort of hybrid between brown-tech and green-tech, in an attempt to at least achieve a relatively stable if slow growing economy in the near term. It is understandable, if frustrating for peak oil activists, that our key institutions will try to keep business as usual going for as long as possible. There will eventually come a time, though, when this effort cannot be maintained, and it will be interesting to see how that plays out. But for now, scenario building of the sort developed by Holmgren in this book can help us make sense of the changes bearing down on us in the years ahead.

This short (115 pages), illustration-rich book is also the perfect tool, along with Chris Martenson’s ‘Crash Course’, for enlightening our elected representatives at all levels of government on the relationship between energy and the economy, the likelihood of energy descent and the need for an economic system that can function in the face of it. Though it is perhaps too soon to tell just how energy descent will manifest over the next few years, this timely and well-written book will certainly contribute to the debate and provide a framework for understanding and working with the changes that are bearing down on us.