There’s something of a debate at the moment, as to whether climate change is man made or not. These debates can become quite heated, with one camp berating the other for being climate change deniers, while the other insists that it’s all part of a natural planetary process that is nothing to do with humans and therefore nothing to worry about.
I have a slightly different take on the matter in that I agree that it is not man made and that it is part of the natural processes of our planet. However, I believe that one important fact gets missed out of the equation by both camps. That is, that humans are just another species on this planet and therefore we are part of its, so called, natural processes. To me, there is no denying that our activities are contributing to driving our climate in a particular direction.
Throughout the history of the Earth the atmosphere has been composed of a complex soup of different elements. This mixture initially was probably created by the geological forces of the embryonic planet and likely varied considerably in its content over millennia. Depending on the levels of certain chemicals in this mix, the atmosphere has been supportive of or lethal to life. It’s possible that life may have had many false starts as the atmosphere swung between these two states. Once life got a definitive foot hold though, it grew to be a serious contributor to the atmosphere. Over millions of years, micro organisms pumped out trillions of tons of a variety of different elements in different concentrations. So that, at different times in the Earth’s history there were higher levels of Oxygen or Carbon Dioxide or Methane or other elements. All of these differing mixtures contributed to steering the climate in a variety of directions. Sometimes hot and dry, sometimes cold and wet. Of course, other factors contributed to driving the climate; volcanic and solar activity being just two. Gradually though, life became a significant player in the creation of the atmosphere and climate of the earth.
We’ve learned that the concentration of specific gases in our atmosphere can have a marked effect on life. For example, high concentrations of Oxygen have supported large bodied animals. The fossil records show us this in the form of Dragonflies with wingspans of 60 centimetres, that lived millions of years ago when the levels of atmospheric Oxygen were much higher than they are now. There have been periods of time when the planet was arid and dry due to higher levels of Carbon Dioxide or Methane.
Throughout most of Earth’s history there has been a notable absence of one particular species. In the absence of this species the climate, driven by a variety of factors including other living organisms, has waxed and waned and done it’s thing. In general these changes have been slow to happen. The exception to this pattern being occasional cataclysmic events such as an asteroid impacting the planet.
Just a few million years ago our species evolved from a group of primates. Natural selection endowed our species with a brain structure that enabled us to step outside of our ecological niche. Now, every living thing has evolved to exploit a particular niche in the ecosystem. So for example, some birds have evolved to catch prey in flight, whereas others have evolved to catch their food in water; yet others will feed at ground level. They are all birds, but each type has evolved and adapted to exploit a particular slot or niche in the ecosystem. A Swallow can no more dive for minnows than a Kingfisher can snatch insects in flight.
We however, slowly at first but then accelerating, began to buck that trend. Driven by the same instincts as every other living organism to find as much food as possible and produce as many babies as possible, we began to move into the niches of other species. We began to claim the resources of these other species as our own. This didn’t happen overnight though. For a long time we existed like many other animals. We moved around with the seasons gathering whatever foods had ripened enough to make them edible. Meat eating was probably limited to eating carrion or stealing from predators. Those same predators were also partly responsible for controlling our populations; disease, starvation, cataclysm and war against others in competition for food also played a part in keeping populations low. While these factors were in play the need to produce as many babies as possible remained a necessity. So for thousands of years we occupied the same ecological niche as the many grazing and foraging animals that we shared the planet with.
For many millennia there weren’t vast populations of any medium or large sized animals. There have been big herds of grazing animals that have existed in their millions, but as far as we know not many species have grown much beyond those numbers. Populations in the billions or trillions were reserved for the very much smaller creatures on the planet; most of which formed the bottom of the food chain for the larger animals above them. All of these animals never moved outside of their ecological niche. This system worked pretty well for keeping some form of status quo that enabled life on the planet to persist.
Our species alone, naturally selected for a different kind of brain function to other species. It gave us the ability to manipulate first non-living matter, (stone, bone, wood) in such ways that gave us a survival advantage over other species. As we progressed, we also learned to manipulate living matter, via actively hunting other animals for food and materials and ultimately learning to create favourable conditions for particular food plants to grow and flourish. In this way we were able to expand our niches so that we could not only catch Minnows, but also snatch insects from the air. We were able to do all this without altering our breeding strategy.
In 1900 our population numbered a little over 1.5 Billion souls worldwide. In just over 100 years that figure has risen to around 7 Billion. To my knowledge, and I always stand to be corrected, no other animal of our size has ever existed in those numbers. In particular, no other animal has ever existed that manipulates the environment in the complex and complicated ways that we do. As a species we are embarked on a vast unintentional experiment with the life sustaining processes of this planet. Largely because, although we were endowed with the technical abilities to shape the environment to suit our needs. We have yet to really challenge the fundamental drives and instincts of our early primate existence; the drives and instincts of every living thing to gain as much resource as possible and produce as many offspring as possible.
I like to think that in recent history we have begun to turn our intelligence away from simply using it as a tool of competition. That we might have grown weary of simply using it as an aid to becoming as resource wealthy as possible in order to increase our numbers as much as possible. That we can get to the point of realising, that allowing our early primate instincts to drive our thinking is not really benefiting us or the rest of life on this planet. I like to think this is happening, albeit slowly.