“When I look at disturbed earth, I may feel upset about how humans mess everything up. If someone tells me that, in fact, a specific disturbance was created thousands of years ago by the passing of a glacier, then my feeling shifts.”
--Joanne Arnott (TCR 3:16 ecologies, 87-88)
As it happens Arnott goes on to equivocate but at the heart of the matter is Anthropogenic Impact, for better or worse. Disturbance has become a key word, although its use is anything but simple. Much of the predicament follows from the multiplicity of scales --temporal and spatial -- that disturbances (events or processes that we know through earth science and natural history) unfurl. That they do so simultaneously means that there is an extraordinary complex mishmashmesh of disturbance out there. The biological recolonization of BC after the ice age, still in process, reacting to an event like Mt St Helens, an El Nino inflected salmon year, a Pine Beetle infestation, a shock of wind in Stanley Park. Earth Science/Natural Science helps us figure these disturbances, these resets to ecologies.
There was little in my intellectual formation, 1970s and 1980s humanities and social sciences, that prepared me for the extent to which some adequacy in understanding earth science and natural history would become so integral to thinking modernity. The extent to which Anthropogenic Impact has come to impact the planetary platform has emerged as an extraordinary intellectual ”forcer” the last two decades and rolling.
My “turn” came with reading David Quammen’s Song of the Dodo (1996). Quammen is a science journalist, in that all important role of getting specialist disciplinary knowledges to the next level of interpretative communities. It is a history of biogeography from the Darwinian moment to the mid-1990s. For the uninitiated it is a wonderful opportunity to get a handle on species formation, species peculiarities and their ecological requirements, the figuring of population dynamics within and between species (food webs) in space and time, the effects of disturbance and so on.
The book works as a travelogue of sorts, as Quammen takes himself off to various corners of the world, where some important turn in the history of speciation and population dynamics and the ongoing present of thinking biogeography is illustrated by situated field work. As it happens, this very widespread return “to the field” coincides with the start of a more comprehensive evaluation of Anthropogenic Impact on biodiversity. Quammen’s work is impassioned, in large part, because time and again, at the sites he traveled to, species needs are under threat. Time and again, habitat degradation, fragmentation and loss are at issue. Ecologies are reset to lowered baselines. Cumulatively the systematics of biogeography, i.e. species doing what they need to do to maintain viable populations in appropriate habitats, has been compromised rendering more and more species less resilient. If species had “culture” for many it would look very dystopian. For others, the adaptive generalists, there is a lot of colonizing to be done, the feral future of dogs, cats, rats, crows, gulls, starlings and no doubt less charismatic bacteria and viruses.
The disturbances and ecologically degraded resets pile up. Biogeography and attendant disciplines notice that the scope of disturbance begins to look more profoundly disruptive than the sum of the parts. The cascading effects through food webs can barely be guessed at. Out of this global Anthropogenic Impact-produced “event” (in evolutionary biology terms), biologists anticipate a species mass extinction.
Quammen is one of the last writers I would nudge you towards to think the other side of all this, the extent to which human imperatives have shaped the land use that has so compromised the processes of biodiversity. But the “disturbance story” he tells is really important. The Song of the Dodo was published in 1996 and climate change is not in the index. The first IPCC report was in 1990. I have little doubt that Quammen was around discussions of climate change. From the preface of another book, I know that Global Warming and Biological Diversity (Peters and Lovejoy, Yale 1992) was available for the community of scientists he was researching amongst. It seems to me that so important was the drive of his argument about biodiversity loss that Quammen did not want to risk losing urgency to the emergent thinking on climate change. We sort of know the story now: Esso and co, dissembling, showing extraordinary bad faith and a profound disrespect for public culture to buttress its sectional interests. In 2007 I get to (we all have to find our way) Climate Change and Biodiversity (Lovejoy and Hannah, Yale, 2005). Climate change is the global “forcer” that animates the processes of species needing to re-establish their place in space given hydrological and temperature regime changes, and make their way in the food webs that disassemble and reassemble. Substantial climate change is the last thing that compromised biogeogaphical processes would “look for.” Anthropogenic Impacts have left huge footprints as it is. The shape and form of those footprints will encumber species response to climate change. Simultaneously, of course, the systematics of modernity will be stressed and redressed to buttress resiliency which will often translate as intensified disturbance at other scales. The difficulty is, given our now deep entanglement in modernity’s productive systems, especially the core species ones of how we participate in the fundamentally important food webs, figuring which disturbances and ecological resets are for better and which are for worse.