Biodiversity: the top-level planetary boundary?

A two-day meeting organised by the Smith School here at Oxford University left me with the creeping impression that although it receives dramatically less attention, biodiversity may well qualify as a more important planetary boundary even than climate change itself. Moreover, it is a staggeringly complicated issue, and is not amenable to many of the technical fixes that might be used to address other boundaries like freshwater, land use and nitrogen.

Just about everything humans do affects biodiversity negatively. This should of course be obvious from first principles: the main objective of farming, for example, is to simplify ecosystems so that their productivity supports one species (ours) only, whilst urban areas are planned as human-centred habitats only. The converse of this is that where humans disappear, such as in the North-South Korea demilitarised area, or the Chernobyl Exclusion Zone, biodiversity rebounds strongly and does better pretty much than anywhere else.

Scientifically-speaking, any biodiversity good news is patchy when compared to the relentless decline in both the abundance and number of other species that share this planet with us. (See Butchart et al, Science 2010 for instance.) At the Smith School conference, slides shown by Simon Stuart (a co-author on the Science paper) showed that whilst the rate of decline in bird species was flat in recent decades, amphibians have seen an accelerated decline, whilst corals have seen losses which are little short of catastrophic.

All this underlines for me the conclusion that we should not be asking biodiversity to make trade-offs in order to deal with climate change. Extinction, after all, is forever, whilst glaciers may one day regrow and sea levels will fall again. Admittedly it will take thousands of years for the human pertubation to the carbon cycle to stabilise in the Earth system, but hundreds of millions of years potentially for evolution to restore pre-Anthropocene mass extinction levels of biodiversity. For me, perhaps the biggest reason to get to grips with global warming early is because it otherwise threatens to outstrip the adaptation capacity of natural species – as is already the case with coral reefs in the warming oceans.

There are some areas where synergies can be realised, for example with REDD + (Reducing Emissions from Deforestation and forest Degradation) in the UNFCCC negotiations: some environmental groups have been very sceptical or even outright opposed to REDD in the past because of the use of markets, but I think this position is counter-productive. Done right, REDD offers the chance to protect the forests and the climate at the same time.

This was a point missed by Bill McKibben in his recent comparison between the Amazon and Canada’s tar sands. McKibben posed the question: ‘If Brazil has to guard its rainforest, why does Canada/US get to burn its tar sands?’ The answer should be obvious: because the Amazon rainforest contains fully a quarter of terrestrial biodiversity, whilst the tar sands just contain tar (although the process of extraction is very damaging to large areas of boreal forest). So if you care about biodiversity, protecting forests is more important than switching off power stations as a climate mitigation option – and therefore worth paying for. (And it is in the financing that equity issues can be addressed properly.)

Just how to pay for forest protection, and for biodiversity generally, was one of the hottest topics at the Smith School conference. There were no easy answers provided. Whilst TEEB has undoubtedly laid some valuable groundwork, there remain many more questions than answers. Biodiversity trends, unlike carbon emissions, cannot be easily measured, quantified and traded. Therefore, in market economics terms, it is much more challenging to price in the externality of biodiversity destruction that likely supports a substantial proportion of global corporate profits.

Even so, I have little doubt that attaching a meaningful price to biodiversity is necessary if conservation is to become the global imperative that it needs to be. Something with no price stays off the balance sheet and therefore has no value in the harsh capitalist world we live in. Monetarising wildlife will not always be appropriate or necessary (or even ethical) but it is surely one of the tools we must use if the relentless decline in other species is to be slowed and eventually arrested altogether.

© Mark Lynas
« · »