Of Mammals and Memory

If you close your eyes and think of the most untouched, pristine habitat in the world, what comes to mind? Do you think of the forests of Borneo? The deserts of Africa? The dark depths of the oceans? Can you imagine anywhere in the world that has been completely unaltered by humans? Unchopped? Unburned? Untouched? Unfortunately, with the advent of anthropogenic CO2, no habitat in the world remains truly pristine.  Even the most undisturbed reaches in the Amazon or the forests of Borneo have already experienced roughly 0.7 degrees Celsius of warming (NASA Earth Observatory).  Nowhere in the world can escape these climactic changes.  Since the ocean absorbs roughly 48% of all CO2 emissions, even in the most remote depths, the ocean’s chemistry is changing (Sabine et al.  ‘The Oceanic Sink for CO2’ 2004).  Roughly half (54%) of all trees that existed before the Agricultural Revolution have been chopped down (Crowther et al. ‘Mapping Tree Density at a Global Scale’ 2015), changing the planet’s ability to process all of the carbon we are pumping into the atmosphere.

Consider the following: what do you consider “natural” or “pristine?” If I told you that giant elephant-like mammals are “natural” to the Americas, would you call me crazy? What about horses? Giant groundsloths in Australia?  In fact, there were once camel-like creatures living alongside massive armadillos and elephants in the Americas.  However, circumstantial evidence suggests that upon the arrival of Homo sapiens ca. 12,000 B.C.E., these species went extinct, bringing about major ecological upheaval in the Americas (Janzen & Martin ‘The Fruit the Gomphotheres Ate’ 1982).  What’s at stake here? These species have been extinct for thousands of years.  Most modern humans don’t consider a lack of megafauna “unnatural” in the Americas.  While there are attempts to reintroduce species of similar taxa into the areas that no longer contain such herbivores, these are typically small movements. So much time has elapsed since these extinctions that the ecosystems have already adapted.

To answer that question, we must look to how people behave.  The average human “generation” lasts approximately 20 years (Carlson & Population Resource Bureau: ‘Population Bulletin, 2009’). During that time, many ecological changes can take place.  Species go extinct, the climate warms, weather patterns change, trees get chopped down, and wild animal populations decline.  All of these things have generally been exacerbated with each generation (Papworth et al. ‘Evidence for Shifting Baseline Syndrome in Conservation’ 2009). Far more importantly, however, people tend to forget what life was like before the change.  When the weather gets warmer or there is a severe drought in Texas, it may be bizarre or unique to those who have lived in the region for 80+ years and remember a time when the weather was cooler or the droughts less severe.  But once these people are gone, and as more and more of these events are experienced, younger people living in Texas will begin to accept frequent droughts as “normal,” and, consequently, their actions may not be as desperate to ameliorate the situation as those of the people who know that circumstances were once better.

As each successive generation dies or forgets about how conditions used to be, there is less and less recognition of change.  The altered state becomes the norm and is accepted as “natural.” For example, we are used to living in a world without elephants in Panama and giant sloths in Australia. After all, no one lived through that time.  Why should we act to correct those problems then? Forests that no longer have species that may have been considered essential are viewed as “pristine” and “virgin.” The same goes for deforestation and overhunting.  Wolves, lions, jaguars—all of these animals used to be far more prevalent and once roamed the regions where cities now stand.  Forests once consisted of more than twice the number of individuals they now contain.

The steps we take to fix these problems are not always taken in the right direction.  For example, you may sometimes hear that forests are re-growing in some places in the tropics.  While this may be true, these sites are simply not the same as old-growth, un-chopped forest.  Barlow et al. (2007) demonstrated, alongside numerous other authors, that chopped and re-grown forest simply cannot compare to “pristine” old-growth in terms of the number of species or their interaction stability.  This means that conservation efforts focused on trying to undo damage already wrought face a much harder challenge in terms of rebuilding ecosystems than do those efforts trying to maintain what is already there.

As unlogged forests disappear, fewer and fewer people will know and experience their awesome, spectacular beauty.  They will accept secondary, re-grown forest as equal to that of old-growth.  The generations who remember what the world was like with more forest land, calmer weather, and greater animal populations are dying off.  Without them, the public imagination loses its baseline for what was once standard.  The consequence of this leads to conservation efforts gradually accepting more and more radical changes over time.  Most people accept that bringing back the wooly mammoth will at most be a biological novelty rather than an ecological necessity.  This is partly due to the time that has passed, but also has much to do with the fact that no one remembers wooly mammoths and what they were like.

Thus conservation efforts lose much of their muster without the persistence of memory to keep them alive.  This means that conservation efforts are running against the clock. Not only the clock of ecological disaster due to extinction, climate change, increased disease exposure, atmospheric ozone depletion, dead zones in the ocean, overhunting, overfishing, erosion, floods, heat waves, droughts, or ecosystem collapse, but also against the human memory.  The memory of truly better times, lost like the trees.

This article was written by Alex Bush. Click here to see more of Alex’s work.