Are Humans Significant? A Scientist Answers

I’m Dr Sami Mikhail and I’m what you’d call a dirt-person or a gravel monkey – the technical term is geologist. I’m presently a Lecturer in Earth Sciences at the University of St Andrews, and I have a disturbingly strong passion for understanding how planets form their atmospheres. Sometimes I ponder abstract concepts like why Venus and Earth are so different and so similar at the same time, and if diamonds are still forming in the deep Earth right now, as my website will attest. However, I also reflect on a number of issues that arise following discussions with my colleagues, students, after reading the news, or while I’m procrastinating. One such topic is: What is the significance of humanity? Naturally, as a scientist, I always consider all possibilities before deriving a conclusion (in light of data.) In this case my logic leads me to conclude that the answer is double-sided. Let’s see where you stand… The case that we are insignificant: Humanity has landed people on the moon, and landed robots on Mars, Venus, Titan, an asteroid (meteorite), and recently, on a comet. We’ve also sent a satellite beyond the edge of our own solar system (with a message saying ‘hello’ attached to it – no joke.) Because we are clever animals, we have invented numerous methods of prediction, quantification, observation, and recording – this is colloquially known as 'science'. Furthermore, we record results and theories through the medium of scripture and thus we learn, collectively, generation by generation. This process was phrased, metaphorically, by the French philosopher Bernard of Chartres (in the 12th Century), who wrote ‘nanos gigantum humeris insidentes’ (this basically means we are all small, but cumulatively we can see as far as a dwarf standing on the shoulders of giants.) In effect, I know a lot of what I know because I’ve read a lot of books, not because I’ve discovered it myself. Thus by extrapolation, this means we (the people of 2016 with access to the internet in our pockets) should be the most informed humans of all time. Based on the cumulative efforts of scientists over the years, we now know that our solar system is roughly 4.6 billion years old, the universe is roughly 13.8 billion years old, and the cosmos is really big. It would take something travelling at the speed of light 91 billion years to get from one side to the other and that's just the bit of the cosmos that's visible to us– aka, it’s bloody huge. We also know that life began between three and four billion years ago, and has been a been a mainstay on Earth ever since – despite some really serious set-backs, termed mass-extinctions. Conversely, human beings have been on Earth for about one million years (but we’ve only been civilised for the last 50 thousand of those years.) We also know that Earth is about 6700 km deep, from surface to the centre of the core, yet the deepest we’ve drilled into Earth is only 12 km (the Kola Borehole in Russia.) More to the point, we are terrestrial animals. This means we solely occupy the thin layer of dry land exposed above the waterline, with the exception of a few people temporarily living on the ISS in a low-Earth orbit.

As a species, our survival ultimately depends on us being lucky enough not to suffer the same fate as the dinosaurs – who were killed by a massive asteroid impact 65 million years ago. Or the bizarre looking creatures called Trilobites – who were killed by large-scale gas-rich volcanism poisoning the atmosphere and oceans 251 million years ago. Take note: both the arrival of a terrifying and massive asteroid and a deadly large-scale gas-rich volcanism will happen again. That’s a fact. So, what can we do to stop this inevitable catastrophe? In a word: nothing. And so, we realise, a) that we have only existed for a fraction of Earth’s history and b) that we have absolutely no control over things like earthquakes, volcanism, and asteroid impacts.

Humanity occupies a very small part of a very small rock in the middle of a small galaxy within a massive cosmos (note, we cannot see the edge of the universe, it’s that big.) If we were wiped out right now, we’d only amount to a very thin layer of rock that preserves the evidence of our existence. In fact, there’d be less preservation of humans as fossils than there would be the things we’ve built. We are not the masters of the Earth, or the solar system, or the cosmos. We are just a highly intelligent, bipedal, omnivorous bald ape who can video call across a planet’s surface, send people and robots into space, then either return them to Earth, or send back data (e.g. photos). Geologically speaking, we are totally insignificant. In 1637 the brilliant French philosopher, mathematician, and scientist René Descartes wrote "je pense, donc je suis" which translates to "I think, therefore I am" to describe our undoubted existence. Now we can play with the two preceding quotes to state: ‘Thanks to several millennia worth of pain-staking scientific enquiry and scholarly curating I know some facts, therefore, I am acutely aware of how utterly insignificant I am.’ The case that we are significant: There’s no point trying to argue that humans are significant on cosmic or planetary scales, because we are not. But what about the potential for humans to be classed as significant on the surface of the pale-blue dot called Earth? After all, we can manipulate DNA, redirect rivers, build canals, and fertilise infertile land; we have God-like powers. We can harness energy from the sun directly (solar) and indirectly (fossil fuels) and we can even harness energy from the tides of the ocean (hydroelectricity) and from the movement of the air (wind). We not only have the ability to harness energy, but we can also store and transport it (in batteries). But these are all ways in which we exploit; what about our influence? We have rendered an excessive amount of animals extinct to the point of fitting the definition of a mass extinction. In fact, due to our ongoing activities (urbanisation, pollution, hunting) modern extinction rates are so high that some researchers suggest a mass extinction is actually under way — some say we are living through the sixth (big) mass extinction to have occurred over Earth's 4.5 billion years of existence. But this one isn’t the work of a volcano, or massive asteroid. The cause of this one is humanity – that previously described insignificant bald ape.

In other news, we have accidentally made a new landmass in the Pacific Ocean comprised entirely of plastic. This new plastic landmass even has a name: The Great Pacific Garbage Patch. The size of this ‘patch’ is poorly constrained; some say it covers 0.41% and some say it covers 8.1% of the whole Pacific Ocean (the largest ocean on the planet.) In fact, some media reports claim it is up to twice the size of the United States (NB: this is just one of the reasons why we should recycle.) Humans are master engineers; we live in an almost synthetic bubble made of plastic, metal, and concrete. This artificial dependence for most of what we do requires a lot of energy (like reading an article in an online-only magazine.) This is where another, invisible issue crops up: Gas. We generate electricity in the same way that the ancients did. Thales of Miletus was a Greek philosopher, mathematician and astronomer, who noted in 600 BC, that if one rubs amber with the fur of a cat, the amber becomes charged and feathers will be attracted to it – this because it becomes electrically charged (not that he used the term ‘electrically charged’.) Now, electricity obeys the laws of physics (like everything does), and therefore generating electricity is fundamentally understood and is the same today as it was the moment of the big bang. Also, we know that energy cannot be made or destroyed and it is only transferable from one state to another, so we need to convert heat or kinetic energy (movement) into electricity. We burn oil or coal, use a blade to force motion due to wind or water motion, or we can use solar panels to directly harness the sun’s energy and cut out the middle man. Another law of physics states that ‘every action has an equal and opposing reaction.’ This is important. When we use oil or coal to generate electricity we are causing an exothermic reaction (a reaction which produces heat and something else.) In short, we add oxygen to hydrocarbons with some heat and this causes them to burn and release a lot of energy. This simple reaction generates a lot of energy in the form of heat to drive turbines that we use to generate electricity. However, this process converts hydrocarbons (molecules made of carbon and hydrogen) into water plus carbon dioxide. This is an awesome way of generating energy. It is brilliant for that purpose. But there’s a big BUT. This process generates carbon dioxide, an invisible and odourless gas. With a global population of around 7 billion and growing (most of which are consuming a lot of energy) the cumulative effect is we are generating a lot of carbon dioxide. This invisible and odourless gas is great at trapping energy from the sun, so more carbon dioxide means higher temperatures. This is a fact; there is no debate.

Another undeniable fact is that the world is warming because of humans. For example, if we hadn’t evolved around 1 million years ago, and hadn’t began burning fossil fuels en masse since the industrial revolution, the projected future and the current average temperature of Earth’s surface wouldn’t be rising like it is. This leaves us with two options: carry on as we are and make unrealistic plans to move whole cities and some nations to high ground and accept that a few billion may die. Or react by utilising less destabilising energy sources. The choice is ours… but let’s see what happens. Despite our great genius as a species, how we choose to do this is presently a discussion for politicians. We wouldn’t expect a politician to decide on a person's medical treatment – which is one reason why lots of people are pissed off with Mr. Jeremy Hunt right now – and likewise, we shouldn’t let the fate of our environment be decided by politicians who lack any reasonable understanding of the science (surely, right?) Environmentally speaking, it is clear that humans are geo-engineering the planet and therefore there is no doubt that we are significant. We have great power in the tiny niche we occupy. So while we are geologically insignificant, we are environmentally potent – and dangerous. The power to consciously geo-engineer the environment is potentially disastrous. But I prefer the glass half-full approach. So let’s re-phrase that last bit. The power to consciously geo-engineer the environment is a skill that means we can improve our living-conditions, and the collective living-conditions of the other life forms that share their lives with us on the only habitable planet we know of, the pale blue dot we call home.