It's an idea that I once argued against in The Leveller (Vol.2, No. 2, p. 12). I lamented the way that new terms such as "environmental responsibility" and "ecological resilience" were being employed by 'green' thinkers across the political spectrum as a replacement for "sustainability", mostly because they realized the genuine difficulties inherent in the latter concept. At a general level Brundtland's idea of meeting the needs of the present without compromising the needs of future generations is certainly an ideal toward which we should strive - how could anyone argue against the idea of forbidding future generations from achieving their needs?
However, I'm willing to admit that this definition of sustainability, as it's commonly interpreted, carries little context about what our present (or future) political economy constructs as a 'need'. Nor does it make the necessary normative commitment towards changing our conceptualization of needs and wants. The concept of sustainability does not reflect the real discrepancy between human needs (which are still not being met in many parts of the world) and social desires (those things that we rich people mislabel as 'needs' - e.g. "I need a snow blower" [Answer: No, you want a snow blower]). Perhaps this is why Marxists in the early 1980s considered sustainability to be a "bourgeois" concept - in some ways it's an ahistorical term that presumes our contemporary mode of production can be transformed into its less voracious sister - capitalism lite?
Resilience is a term that came out of the environmental change literature (see Peter Timmerman's Vulnerability, Resilience and the Collapse of Society, 1981). The idea of resilience, applied in a socio-ecological context, refers to the adaptive capacity of a system in the face of changes. As Carl Folke et. al. explained:
More resilient social-ecological systems are able to absorb larger shocks without changing in fundamental ways. When massive transformation is inevitable, resilient systems contain the components needed for renewal and reorganization. In other words, they can cope, adapt, or reorganize without sacrificing the provision of ecosystem services (Folke et al, 2002, 438).There is something in this concept that evades the problems associated with "sustainability" by not making any assumptions about needs and wants, and by placing humans in a reactive role as opposed to positing them as an omnipotent shaping force. With a resilient system, the needs of future generations is up for discussion - we may have good guesses about what might be needed, but we always assume scenarios in which our ability to fulfill those needs are made vulnerable. Resilience causes us to dig down and prioritize our needs and wants.
However - and here's the fence-sitter in me - there's also something fundamentally conservative about resilience (and sustainability too). Both ideas stem conceptually from a fear of change. What exactly is it that we are trying to sustain in sustainability? Is it really worth trying to make a system resilient to external forces of change when the original system in itself is socially and ecologically corrupt in other multifaceted ways?
Let me use Easter Island as an example. We've all heard the story of how that civilization collapsed - ultimately resulting from excessive deforestation (see Jared Diamond's book Collapse). The downed trees were needed for firewood, but also to move the heavy stone statues that have now made the island famous. As a thought exercise, let us pretend that the people of Easter Island had adopted a 'sustainable development' model (a policy of trying to meet contemporary needs without compromising needs of the future). Would they have been able to foresee the role that deforestation played in their unsustainable political economy? Moving statues was a social need at the time. Even if they had understood the importance of trees to their long-term subsistence, would they have been able to curb their excessive levels of deforestation before irreversible runaway socio-ecological damage? In other words, would an understanding of sustainable development have enabled them to change their way of life, or would it have lulled them into a false sense of hope that their existing practices could somehow be made "sustainable"? The same could be said of resilience: Would the people of Easter Island have been building a straw house in trying to build adaptive capacity? Even if they had built a system that was temporarily resilient to the sudden and total lack of trees, would it have been worth it (or even possible) to pursue life on a treeless island in the long term?
I don't know the answers to these questions. It's just a thought exercise I'm employing to question the usefulness of resilience and sustainability to our present socio-ecological problems. On the one hand, the idea of building societies resilient to changing material realities (on account of climate change, pollution, ecosystem damage, etc.) just seems like common sense. On the other, I worry that we're trying to make the wrong system resilient - maybe we need social change before trying to improve our adaptive capacity, so that the system we try to sustain is worth sustaining?!