Category: Climate change

My cynicism about global gabfests intended to improve the human condition yields to no-one. So you can imagine how I felt when work asked me to share my thoughts on Rio+20. Delighted, I shared them. They were judged unsuitable. So, this being the age of the internet, I shared them myself. Takeaway thought: People – with the possible exception of some biologists – have no clue about what sustainability actually entails. If they did, they wouldn’t even pretend to embrace it. It’s scary.

It thus came as a pleasant surprise to discover that, on the eve of Rio+20, PLoS Biology published an essay on The Macroecology of Sustainability. ¹ Joseph Burger and his colleagues do a fine job of putting the evidence out there for all to see. Their takeaway thought:

Over the past few decades, decreasing per capita rates of consumption of petroleum, phosphate, agricultural land, fresh water, fish, and wood indicate that the growing human population has surpassed the capacity of the Earth to supply enough of these essential resources to sustain even the current population and level of socio-economic development.

In other words, never mind about becoming sustainable some time in the future. Things aren’t sustainable now.

They offer many examples to get their point across, although all require a certain openness to be convincing. The salmon fishery of Bristol Bay (the bit of the Bering Sea north of that line of islands stretching west from Alaska) is lauded as a success of sustainable fisheries management because annual runs of sockeye salmon – 70% of which is harvested each year – have not declined. Which is great from a small-minded human perspective. But as Burger at al. point out: ²

When humans take about 70% of Bristol Bay sockeye runs as commercial catch, this means a 70% reduction in the number of mature salmon returning to their native waters to spawn and complete their life cycles. It also means a concomitant reduction in the supply of salmon to support populations of predators, such as grizzly bears, bald eagles, and indigenous people, all of which historically relied on salmon for a large proportion of their diet. Additionally, a 70% harvest means annual removal of more than 83,000 metric tonnes of salmon biomass, consisting of approximately 12,000, 2,500, and 330 tonnes of carbon, nitrogen, and phosphorus, respectively. These marine-derived materials are no longer deposited inland in the Bristol Bay watershed, where they once provided important nutrient subsidies to stream, lake, riparian, and terrestrial ecosystems. So, for example, one apparent consequence is that net primary production in one oligotrophic lake in the Bristol Bay watershed has decreased ‘‘to about 1/3 of its level before commercial fishing’’. Seventy percent of Bristol Bay salmon biomass and nutrients are now exported to eastern Asia, western Europe, and the continental US, which are the primary markets for commercially harvested wild Alaskan salmon.

The Bristol Bay salmon fishery exemplifies the first of three principles without which any approach to sustainability is bound to fail.

1 Thermodynamics and the Zero-Sum Game

[C]ontinual flows and transformations of energy are required to maintain highly organized, far-from-equilibrium states of complex systems, including human societies.

2 Scale and Embededness

[S]ocioeconomic systems are not closed or isolated, but instead are open, interconnected, and embedded in larger environmental systems.

3 Global Constraints

The emphasis on local and regional scales—as seen in the majority of the sustainability literature […] —is largely irrelevant if the human demand for essential energy and materials exceeds the capacity of the Earth to supply these resources and if the release of wastes exceeds the capacity of the biosphere to absorb or detoxify these substances.

This last is the one on which I have been fixated, and the most useful element of the paper, for me, is that Burger et al. bring the old estimates of human appropriation up to date, not only with respect to primary productivity – the sun’s energy captured by plants – but also for a host of other resources on which human life depends.

The bottom line is that the growing human population and economy are being fed by unsustainable use of finite resources of fossil fuel energy, fertilizers, and arable land and by unsustainable harvests of ‘‘renewable resources’’ such as fish, wood, and fresh water. Furthermore, attaining sustainability is additionally complicated by inevitable yet unpredictable changes in both human socioeconomic conditions and the extrinsic global environment. Sustainability will always be a moving target and there cannot be a single long-term stable solution.

Of course there is a backlash ³ against this kind of conclusion, and PLoS Biology gives space to a rejoinder from John Matthews and Frederick Boltz of Conservation International, who ask “Are we doomed yet?”. ⁴ And of course I am biassed, but I did not find anything really compelling in their piece, which seemed to be long on arm-waving appeals and short of anything approaching evidence. They do advance some cases, such as the Montreal Protocol to stop the ozone hole, but most of these fall into the succession of successes that have caused almost everybody, especially economists and policy makers, to discredit the fundamental party-pooping dynamics first uncovered more than 200 years ago by Thomas Malthus.

Throughout, Matthews and Boltz appeal to humanity’s ability to innovated its way out of a tight spot, and admittedly it has often done so before. But do the negotiators at the global gabfests have any appreciation of how tight that spot is today? Clearly not, if we judge by actions rather than intentions.

Matthews and Boltz conclude:

Our intuition is that fear has proven to be a far less helpful means of communicating the need for positive change than hope.

They may well be correct in their intuition; we humans are enormously adept at ignoring little local difficulties. But is an “intuition” about “hope” really the best they can do?

Burger et al. offer an interesting way of looking at sustainability: the military siege, which attempted to block flows into and out of cities and castles, often successfully.

From this point of view and in the short term of days to months, some farms and ranches would be reasonably sustainable, but the residents of a large city or an apartment building would rapidly succumb to thirst, starvation, or disease.

How I’d like to lay siege to a gathering of global negotiators.