Humans Are Now Experiencing Changes to the Environment on a Geologic Time Scale

By: Nora Germain

Depending on where you look, the human lifespan is currently only about 75 to 100 years, although modern medicine may extend that a great deal soon. Our lives are too short to comprehend, much less observe, the huge changes that the Earth undergoes in geologic time spans. Geologic time is defined as the scale that time moves in related to geology (Earth’s physical structures), so generally, it means enormous amounts of time. For example, Earth is about 4.5 billion years old, and the oceans have been around for about 3.8 billion years. Trees have existed for about 370 million years, and humans have only existed for about 200,000 years. 

At times, Earth has been completely ice free. During the Jurassic Period for example, about 150 to 200 million years ago, dinosaurs lived on a planet that was much hotter with sea levels that were much greater than they are today. Earth has also been fully covered in ice, during a time period of about 100 million years in total, which started about 715 million years ago called “Snowball Earth.” 

Earth has gone through enormous changes during its roughly 4.5 billion year timeline, but for perhaps the first time in human existence, we are here to witness changes that are taking place on this grand geologic scale in our lifetimes. Unsurprisingly, it’s hardly making the news. 

According to the National Oceanic and Atmospheric Administration, or NOAA, as well as the Scripps Institute of Oceanography, we have now passed between 412-420 parts per million (ppm) of greenhouse gases in our atmosphere. Some reports show that we have indeed surpassed 420 ppm. This mostly consists of carbon, but also includes methane and other heat-trapping gases which rapidly warm our planet. That’s why they’re called “greenhouse gases.” 

What’s historic, on a geologic scale, is that Earth has not experienced this level of carbon and/ or greenhouse gases in 3.6 million years, or put in other terms, all of recorded history (plus a lot more time). Why do we care if we’re setting a new record for how much heat we can trap in the atmosphere? The easy answer is that humans have never lived in these atmospheric conditions before, since humans have only existed for about 200,000 years. This is not an experiment that is wise to undertake, but we are going to do it anyway. At the present moment, there is not a way out of it.

Not only are we rolling the dice on our ability to survive in a much hotter environment with higher sea levels, less arable land to farm on, and so forth — but we are also rolling the dice on our natural environment. Can the coral reefs survive this? Can the Amazon rainforest survive this? We not only need the oxygen that these natural environments provide the world with — but we also need the food and medicines that come from these vast natural places. We also need to protect them from a moral standpoint. Without thriving life, our planet might be a lot like Mars.

While it’s true that many of these animals and plants have existed for millions of years, the individuals that populate our Earth today have not, which is why even though coral reefs have existed on Earth for a quarter of a billion years, the ones that live in the oceans today are only about 10,000 years old at most. They are bleaching and dying, rotting away in the ocean at alarming rates, and most of this is due to spikes in heat. We may lose all reefs this century.

Of course evolution has a potential role to play in this race against time. There are some organisms who may be able to evolve, or at least migrate, in order to survive in these new and changing circumstances. However, evolution usually takes place on a scale of about a million years, and in this case, we are changing the landscape and atmosphere in about 100, so most organisms will go extinct before they are able to evolve in necessary ways, and that’s to say nothing of deforestation, pollution and other more direct environmental crimes.

Something extremely valuable to remember when thinking about a degree or two of heat increase on our planet is to think of the way that a couple of degrees can affect human beings in terms of our own internal body temperatures. If our temperature rises even three degrees, that’s considered a fever. Five or six degrees in temperature rise over a sustained period of time can be an emergency, or fatal, even to a strong and healthy person. It’s important to treat our planet and the wildlife on the planet with the same concern that we would ourselves.

So, here we go with this new experiment. It’s going to take years or possibly decades to appreciate the logical conclusion or outcome, and I fear that most people on our planet are not even aware that they are part of such a risky and inescapable gamble. According to NOAA’s report, sea level wasn’t just a little bit higher 3.6 million years ago, when the atmosphere was most similar to today. It was 78 feet higher (23.7 meters). If our sea levels rise 78 feet, life as we know it will be almost certainly destroyed. As Greta Thunberg once said, “You can’t make deals with physics.”

There is a lot that can be done to potentially slow the rate of greenhouse gases entering our one collective atmosphere. There isn’t any plan or technology that can remove heat from the atmosphere however, or stop, much less reverse the consequences both short or long term of climate change. There is carbon trapping technology, but it’s not used on a widespread scale due mostly to economic factors.

Such technology will hopefully be optimized and more widely used during our next industrial revolution, or what some call the “decarbonization era.” It will need to be deployed in a massive way in order to address the changes we have made and “baked in” to our planet. Protecting the oceans and forests, as well as expanding already protected areas and leaving them alone to regenerate will also help in the long term (long term meaning decades or possibly — hundreds and maybe thousands of years).

In the short term, or for the next few generations, this experiment is going to play out whether we like it or not. It’s not often that humans get to witness geologic changes like these, but we are about to find out what happens when we change the underlying systems that have allowed humans to evolve, travel, farm, govern and thrive.

These changes are not going to happen overnight, just as the emitting of massive levels of greenhouse gases did not happen overnight. However, it’s important that we bear witness to the experiment that we are now all part of on Earth, because whether you’re talking about human time or geologic time, what we’re doing is dangerous, unprecedented and historic.

Someday in the future humans may be a multi-planetary species and we may even have the technology to teleport or travel through wormholes. I’m not as worried about the fate of Earth’s life way into the future. Maybe Earth will be a decrepit desert by then, or it will be the thriving natural paradise it was in the time of Galilio* (*minus the colonial plundering).

However, it seems like an interesting cosmic fact that humans gained the capability to leave their planet at more or less the exact time that the natural environment began to collapse. Both of these events were billions of years in the making, yet I feel we don’t have to choose one over the other. I believe we can pursue our adventurous dreams to explore space and rehabilitate our home planet at the same time.

While more and more people are becoming astronauts and huge advancements are being made in space travel, we are still a long way off from being able to permanently move any portion of civilization off of Earth. This is why we must find a way to survive and hopefully reverse this unsafe carbon experiment that we are in now, and we must courageously and faithfully help one another to weather the storm.

Further Reading and Resources:

Chasing Coral Film

USA Today

Snowball Earth

Jurassic Period

-Mauna Loa Observatory in Hawaii-Mission Blue Film

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