Any given place on the earth will have been really hot, freezing cold, wet, dry, flooded, parched, ravaged by fire, hit by tsunami or earthquake, bathed in toxic gases from volcanic activity and seen the effects of meteorite strikes large enough to send gigatons of dust into the jet stream. It has all happened.
The only thing needed for all of these events to occur in any one place is a very, very long period of time. So long that, although we can write down the length of time in numbers, it is beyond our human perception.
One million years is a yawn in evolutionary time and a blink in geological time.
Certainly when impacts occur, there is a change to the way the environment works. Ecological processes may speed up, slow or shut down for a while and many species may be lost until others arrive more suited to the new conditions. But over time a new pattern emerges and life continues. No matter the severity or extent of change, disturbance and impact, planet earth has absorbed it and kicked on.
Even when the disturbance is extreme, such as a volcanic eruption sufficient to put the landscape under two feet of caustic ash, there is a period of apparent sterility until rain and the arrival of microbes start to turn the ash layer into something tolerable for bigger organisms. In a few hundred years, a little longer if the climate is cold, the process of succession will return a green mantle to the landscape.
So for the environment, there is no such thing as a problem, only change.
Not only is there change, but change is normal.
Enter Homo sapiens, modern humans, us. Initially we were of minimal consequence to this overall pattern of change. We started out with just a few million individuals spread far and wide in small groups in sync with the grand scheme of predator and prey on the savannas. This arrangement persisted for just shy of a million years, and then, all of a sudden, we figured out novel ways to appropriate resources – lots of them.
In an evolutionary blink we entered an exponential phase of population growth and migrated to all continents. Today we number 7 billion souls, with an additional 8,000 net added every hour (1.3 million per week). Together we appropriate over 40% of the global primary production, modify landscapes everywhere and have even started to change concentrations of atmospheric gases. If Homo sapiens were a species of insect or rodent the description would be ‘plague proportions’.
Still this is not a problem for the environment.
Voracious herbivores have come and gone before. Appropriation of resources by one species simply leaves less carbon to fuel other species and most plagues pass. For the environment, a plague is just another source of change.
Not so for us. We see change as a problem, a big one if it means that our means of production are compromised, or worse, our primary needs for food, water and shelter might not be met.
Unlike the environment, we have an awareness of self that makes us worry about change. We alter the environment to best produce resources for us and then we want it to stay in that modified state, steadily delivering the resources we require. Except that the very modifications we induce are a driver of change to the ecological processes that support primary production. They are disturbances as severe and widespread as any other.
Not only do we disturb; we have developed a system that allows a handful of us to supply the primary resources for everyone else in return for cash. This has too many consequences to describe here but it means that most of us can bunch up and live far away from the sources of our food and water. We then use energy to move these resources, and ourselves about the place.
As the modified system of production is efficient (initially at least) most of us have time to consider, manufacture and acquire goods that supply our secondary needs – we acquire lots of stuff. These goods use up materials that we have found in the landscape and under the earth. We extract and transform natural resources and further modify the landscape generating by-products as we go.
Even when this goes on for 7 billion humans scrambling for food, water, shelter and wants, the environment does not see this as a problem. It is merely another novel disturbance akin to a meteorite the size of a city crashing into the desert. This is bad news for humans and their needs for food and water but just another bout of disturbance and change for the environment. It will shrug and go on just as it has through deep ice ages, big meteorite impacts and a host of other disturbances that are just the way of things.
So what if there is a mass extinction? This has happened half a dozen times before and over time biodiversity has come back stronger. It will do it again, only maybe not with quite the array of mammal species we have now.
Pretending that the environment has a problem is a deflection. In the long run there are no problems for the environment, only problems for us.