Shifting baselines refers to a change in what people think is normal.
For most of history, the world around us changed very slowly. People didn’t see things becoming different during their own lifetimes, and didn’t realize that their environment was not quite the same as what their great-grandparents had experienced. The slow change in reality, from generation to generation, without a corresponding awareness of the change, is an example of shifting baselines.
Experts now think that shifting baselines are part of the reason for why megafauna – huge animals – disappeared from North America. Our continent used to be populated by mammoths, giant sloths, camels, and other kinds of big wildlife. Now, all of these species are gone. Why?
Experts think that these animals were hunted to extinction by humans, but very slowly. The early human inhabitants of North America probably only killed a few members of each species every year. But, because large animals reproduce so slowly, even this was enough to cause a gradual decline in their populations.
The key word is gradual – each generation of humans saw the number of large animals they shared their world with, and didn’t realize that that number was somewhat less than it had been in the past. By the time it became clear to people that the animals they liked to hunt were heading towards extinction, it was too late for those species to recover.
Today, we notice that we don’t see many animals in our yards. But most of us are not really aware of how many animals we don’t see. Not knowing that the total number of birds in North America used to be a billion more than it is today, not realizing that the total number of wild mammals on our planet is less than half what it was a few decades ago, we take the absence of animals in our neighborhoods as disappointing but not unusual. Our baselines have shifted.
Now, though, things are changing so quickly that we do notice the differences within our own lifetime. People of a certain age recall that the skies used to be filled with monarch butterflies in the fall, but now we see only a few of these beloved travelers during migration season. People remember when there was more nature in our communities. People remember when there were not so many severe storms.
The speed with which damage to our environment is happening is, in a lot of ways, bad news. But the silver lining may be that we can see the changes occurring. This means that, instead of complacently thinking that the world has always been this way and there is nothing wrong, we can point to the changes we don’t like, remind ourselves that things used to be better, and demand that our society stop moving down a dangerous path.