Time and our limited perceptions frequently obscure the impermanence of the world.

On a recent hike in the coastal redwoods, a solitary old growth tree stood.  A short fence surrounded it, and a nearby sign announced it as an example of what once had blanketed the slopes and valleys.  Without this tree, a casual visitor may not have noticed the forest was filled with second- or even third-growth trees, although they may have noticed all the stumps.  Redwood lumber is prized for its ability to withstand rotting, enduring for years beyond a fir or pine structure.  Redwoods grow fast, springing from the stumps and downed “nurse” logs without the need for replanting.  A 50-year-old forest with sizable trees may obscure the fact of past harvesting of the trees unless you are conversant with the other characteristics of an old-growth forest.  Forests such as this may give us the illusion of a nature that self-corrects with little action on our part other than leaving it alone for a few years.

As visitors to natural areas we anticipate seeing the same features and views we first saw reading National Geographic as a child.  And usually nature cooperates, with landscapes little altered other than human intrusions.  Visiting Yosemite Valley we may notice the scars of rockslides on the valley walls, and maybe even see one ourselves.  Most people would see those slides as a rare occurrence without realizing much of the topography is a result of downslope movement of one kind or another.  In the visitor’s mind, the landscape is timeless, looking much as it did when the early popularizers such as John Muir first described the setting.  

In school, we learn about how the world was very different in the past, although you have to go quite far in the past to find a time when it would have appeared appreciably different — much longer than what human history can hold.  Even a clearcut in the coast redwoods starts looking as it once did within a single human lifespan, visual evidence of how nature really does stay the same even when we interfere.  Apparently.

Humans are able to recognize change within their own lives as they age and experience various stages of growth.  We are even able to note the aging of our parents as they become someone different than the people we grew up with, although the changes took place so slowly we were barely aware of them.  Maybe it is the same phenomenon that makes me continue to see my unchanged self when looking in the mirror.  My aging has crept up on me without any apparent drastic changes to my appearance.  Even the events of our lives don’t appear to create too many distinctions.  The marriages of two of my children and the birth of a grandchild remind me I have aged, however the visage in the mirror remains a younger self who isn’t possibly old enough to have grandchildren.  

The slow changes in our landscape and global systems are perhaps similar: The changes are too slow and incremental and taking place elsewhere for us to notice.  Even the increasing occurrence of large events such as polar vortexes, unprecedented wildfires, and the melting of the polar ice caps are tangential to our own lives, at least for most of us, and our immediate environment continues to show little to no change.  Scientists attempt to use data to demonstrate the magnitude of the climate changes taking place, however these don’t match with our daily experience or expectation of the permanence of the world.  As noted previously, humans struggle to think in the time scales on which most global changes take place.  When presented with actual images of locations taken many years apart most people are able to pick out the differences, even in places such as redwood forests and the cliffs of Yosemite.  But the basic background is much the same.  Going back still further, we have only renderings of what we imagine it must have looked like, using data from tree rings or ice cores or accumulated sediments to argue for the truth of what we present.  In the same way, renderings of potential future impacts are frequently used to project what eventual outcomes may look like.

One of the things educators do to engage students when they are unable to bring an actual phenomenon into the learning environment is to bring in an analogous one.  When used appropriately, these analogues can stand-in for the actual phenomenon we wish the learners we are interacting with to understand enough to explain using evidence they collect themselves.  This requires creating concrete learning opportunities that are open-ended enough to allow students to form their own conclusions, and not just to participate in confirmation activities.  Climate change education tends to use the same data sets, asking students to recreate the same graphs they see in the media.  Having every student in every classroom using the same data points to create the same graphs does nothing to create even a momentary cognitive dissonance as they struggle to make sense of their experience.  The outcome is predetermined with no room for individual thought.  In an extreme point of view it is almost indoctrination, where critical thinking and dissent is disallowed.  What we want is for young learners to have the opportunity to examine a phenomenon, not just a data set, gather evidence, then make an argument explaining the phenomenon based on their own evidence.  Ideally the phenomenon is one they encounter in the context of their own lives.

Change is all around us.  And it always proceeds at its own pace, usually at one we are unable to observe at a single glance, or even within the constraint of a single human life span.   Even then other factors may obscure the perception of change.  The solution for educators is surely not simple, and it may involve looking at how learners experience the world over their entire school career.  Some standards encourage the observation of patterns decipherable over the course of a single year.  The ones we as science educators concerned with the state of our planet must bring into student experience are those we can only decipher over many.  A singular experience is not enough to convince someone of the impact of slow change.  To truly understand, many experiences over a lifetime and more are necessary.

This post originally appeared in the Summer 2021 issue of Mercury Magazine, a publication of the Astronomical Society of the Pacific