Way back in 1989, Jared Diamond defined the ‘evil quartet’ of habitat destruction, over-exploitation, introduced species and extinction cascades as the principal drivers of modern extinctions. I think we could easily update this to the ‘evil quintet’ that includes climate change, and I would even go so far as to add extinction synergies as a the sixth member of the ‘evil sextet’.
But the future could hold quite a few more latent threats to biodiversity, and a corresponding number of potential solutions to its degradation. That’s why Bill Sutherland of Cambridge University recently got together with some other well-known scientists and technology leaders to do a ‘horizon scanning’ exercise to define what these threats and solutions might be in the immediate future. It’s an interesting, eclectic and somewhat enigmatic list, so I thought I’d summarise it here. The paper is entitled A horizon scan of global conservation issues for 2010 and was recently published online in Trends in Ecology and Evolution.
In no particular order or relative rank, Sutherland and colleagues list the following 15 ‘issues’ that I’ve broadly divided into ‘Emerging Threats’ and ‘Potential Solutions':
- Microplastic pollution – The massive increase in plastics found in the world’s waterways and oceans really doesn’t have much focus right now in conservation research, but it should. We really don’t know how much we’re potentially threatening species with this source of pollution.
- Nanosilver in wastewater – The ubiquity of antimicrobial silver oxide or ions in products these days needs careful consideration for what the waste might be doing to our microbial communities that keep ecosystems alive and functioning.
- Stratospheric aerosols – A simultaneous solution and threat. Creating what would in effect be an artificial global cooling by injecting particles like sulphate aerosols into the stratosphere might work to cool the planet down somewhat. However, it would not reduce carbon dioxide, ocean acidification or other greenhouse gas-related changes. This strikes me as a potential for serious mucking up of the global climate and only a band-aid solution to the real problem.
- Deoxygenation of the oceans – Very scary. Ironically today I was listening to a talk by Martin Kennedy on the deep-time past of ocean hypoxia and he suggests we’re well on our way to a situation where our shelf waters could essentially become too anoxic for marine life to persist. It’s happened before, and rapid climate change makes the prospect plausible within less than a century. And you thought acidification was scary.
- Changes in denitrifying bacteria – Just like we’re changing the carbon cycle, we’re buggering up the nitrogen cycle as well. Changing our water bodies to nitrogen sources rather than sinks could fundamentally change marine ecosystems for the worse.
- High-latitude volcanism – One of these horrible positive feedback ideas. Reducing high-latitude ice cover exposes all these slumbering volcanoes that once ‘released’, start increasing atmospheric gas concentrations and contributing to faster ice melt and sea level rise.
- Trans-Arctic dispersal and colonisation – Warming polar seas and less ice mean fewer barriers to species movements. Expect Arctic ecosystems to be a hotbed of invasion, regime shifts and community reshuffling as a result.
- Invasive Indo-Pacific lionfish – Not one I would have focussed on, but interesting. These spiny, venomous fish like to eat a lot of other species, and so represent a potentially important invasive species in the marine realm.
- REDD and non-forested ecosystems – Heralded as a great potential coup for forest preservation and climate change mitigation, focussing on maintaining forests for their carbon sequestration value might divert pressure toward non-forested habitats and ironically, threaten a whole new sphere of species.
- International land acquisition – Global financial crises and dwindling food supplies mean that governments are acquiring more and more huge tracts of land for agricultural development. While this might solve some immediate issues, it could potentially threaten a lot more undeveloped land in the long run, putting even more pressure on habitats.
- Synthetic meat – Ever thought about eating a sausage grown in a vat rather than cut from a dead pig? It could become the norm and a way of reducing the huge pressure on terrestrial and aquatic systems for the production of livestock and fish for human protein provision.
- Artificial life – Both a risk and a potential solution. While I’ve commented before on the pointlessness of cloning technology for conservation, the ability to create genomes and reinvigorate species on the brink is an exciting prospect. It’s also frightening as hell because we don’t know how all these custom-made genomes might react and transform naturally evolved ones.
- Biochar – Burn organic material (e.g., plant matter) in the absence of oxygen, you get biochar. This essentially sequesters a lot of carbon that can then be put underground. The upshot is that agricultural yields can also increase. Would there be a trade-off though between land available for biochar sequestration and natural habitats?
- Mobile-sensing technology – Not so much a solution per se, but the rapid acceleration of remote technology will make our ability to measure and predict the subtleties of ecosystem and climate change much more precise. A lot more work and application required here.
- Assisted colonisation – I’ve blogged about this before. With such rapid shifts in climate, we might be obliged to move species around so that they can keep up with rapidly changing conditions. Many pros and cons here, not least of which is exacerbating the invasive species problems around the globe.
Certainly some interesting ideas here and worth a thought or two. I wonder if the discipline of ‘conservation biology’ might even exist in 50-100 years – we might all end up being climate or agricultural engineers with a focus on biodiversity-friendly technology. Who knows?
Sutherland, W., Clout, M., Côté, I., Daszak, P., Depledge, M., Fellman, L., Fleishman, E., Garthwaite, R., Gibbons, D., & De Lurio, J. (2009). A horizon scan of global conservation issues for 2010 Trends in Ecology & Evolution DOI: 10.1016/j.tree.2009.10.003