"The truth is that there is as yet no credible, socially just, ecologically sustainable scenario of continually growing incomes for a world of 9 billion people."

This rather terrifying quote is from "Prosperity without growth? The transition to a sustainable economy," published by the Sustainable Development Commission, the U.K. government's sustainability watchdog. The report is the result of a year-long inquiry by the commission led by Professor Tim Jackson, who has been developing the basic concept across his entire career.

The findings matter because they address fundamental questions. How come our current economy is unsustainable? How might we transition to a sustainable economy?

Our current economic difficulties make it easy to say such challenges are for another day but, as Jackson says, "Prosperity without growth is a good trick to have up your sleeve when the economy is going down the pan."

It is difficult to do full justice to the depth and breadth of the report, but here it is in 10 bullet points:

1. Economic growth fails to deliver prosperity, now or in the future. Poorer nations urgently need further economic development, but do already-rich nations?
2. The current turmoil and recession is the result of the sort of growth we were pursuing.
3. Understanding prosperity as possessions or income has failed because, beyond a certain point, more of either does not increase people's life satisfaction or development indicators.
4. The growth dilemma: The current economic configuration means that growth is unsustainable but "de-growth" (planned reductions in economic output) is unstable.
5. There has been relative decoupling (less impact per unit of activity) in the recent past, but we need absolute decoupling (less impact in total).
6. We are currently trapped in an "iron cage" of production and consumption of novelty.
7. A green stimulus is sensible in the short term but still assumes a return to continual consumption growth.
8. A new macroeconomics for sustainability would be based on stability, distributional equality, sustainable levels of throughput and protecting natural resources.
9. The current culture of consumption will need to become a social logic of "flourishing within limits."
10. Governments need to find a new way of ensuring stability that also secures the future of prosperity.

It is worth pulling out a longer quote from the report about why relying on eco-efficiency is insufficient without system-level change.

"Efficiency is a grand idea. And capitalism sometimes delivers it. But even as the engine of growth delivers productivity improvement, so it drives forward scale of throughput. Nowhere is there any evidence that efficiency can outrun -- and continue to outrun -- scale in the way it must do if growth is to be compatible with sustainability."

Fundamentally, the message of the report is this: If we try to build a sustainable future that requires everyone to play status games through material possessions -- that is, we continue with our culture of consumerism -- then we will fail.

This is a big challenge to a lot of us who work with companies on sustainability. In our work with businesses here at Forum for the Future, we have been pushing the "win-win" opportunity agenda of putting sustainability at the heart of business strategy, product and service innovation and new business models. Such efforts are leading edge today, but they are also, unfortunately, within the current culture of consumerism.

Businesses profiting from more sustainable products and services will not be enough. There will need to be change in the very marrow of the macro-economic system to create new "win-win" business opportunities that grow a culture of flourishing within limits, instead of consumerism.

The report ends with 12 steps to a sustainable economy. At first glance they can seem unlikely. But many of those steps match with what the Obama administration has proposed, like investing in infrastructure, regulating finance and imposing clearly defined emissions caps. And, history shows that different forms of capitalism grow out of times of change and crisis.

The possibility on offer is a future where "humans can flourish, achieve greater social cohesion, find higher levels of well-being, and still reduce their material impact on the environment." That is something worth trying for. We are only at the beginning of that difficult transition.

David Bent is head of Business Strategies at Forum for the Future, a nonprofit sustainable development organization based in the United Kingdom.

_{Image: Cover of the "Prosperity Without Growth" report, courtesy of the Sustainable Development Commission}