oops our bad....
It's hard to believe that even with 7,214,827 (as of the writing of this article) billion people on the planet that we could really be having any major effect on the Earths ecosystems and biodiversity, but unfortunately its seems that we do. Their is a growing body of evidence that we are affecting the biodiversity on this planet on a scale not seen since the asteroid killed off the dinosaurs 65 million years ago and gave rise to the current dominance of mammals over reptiles. Its seems just a bit ludicrous that one species even one as "smart" as humans could do damage on the same scale as a 10 kilometer asteroid hitting the planet, but in our own unique way we are doing this. Before I can jump into this topic really deeply I think a little history is needed to put the current extinction event into perspective.
The First Five
Their have been a total of five mass extinctions in the past that have done their damage to the biodiversity on this planet.
- End-Ordovician- Wiped out around 85 % of all species that existed at the time most of which were sea life of varying shapes and sizes. This extinction occurred around 440 million years ago and was believed to be caused by a very intense ice age.
- Late-Devonian- This particular event is thought to occurred around 375-359 million years ago and was spread out over a couple million years and wiped out anywhere from 79-87 % of all species. Many different types of catastrophes have been blamed for this event from anoxia in the oceans, rising sea levels and global cooling.
- End Permian- This extinction event is considered to be the most damaging to the ecological record with over 97% of species disappearing from the Earth. This one is thought to have occurred from a rapid warming and drying out of the earth.
- End Triassic- Wiping out 76-84% of species this loss of life is probably one of the least understood of all the events. It occurred around 201 million years ago and it's probably cause has to do with falling sea levels and drying out of the land masses.
- End Cretaceous- Perhaps the most studied since it is the most recent extinction at around 65 million years ago this one led to the demise of the dinosaurs. Most scientists are in agreement that a comet or asteroid played a role in this extinction but the scale of that role is still hotly contested.
The Sixth Extinction
We are a species of change and adaptation. That has what has led to our success and our eventual domination of this world. We harnessed the power of fire, invented the wheel and domesticated animals to perform our labor. We built farms, communitiesCredit: personal Photo and monuments to our greatness and all the while we spread over all corners of the planet. While all of this is great and dandy for us it has had unintended consequences on the species we share this planet with. There has been human caused extinction event for as long as there has been Homo sapiens the only thing that has really changed in the past two hundred years or so is the rate.
A Few Numbers...
- Background/Normal extinction rate is calculated to be 10-100 species per year.
- In just the rain forest the species loss has been calculated up to 27,000 species per year.
- As many as 30-50% of all species currently alive could be extinct by mid century.
How are we doing it?
Were doing it the same way species have always affected other species through direct competition for resources. Through the process of the Industrial Revolution and the modern population numbers we have both the means and need to affect large swaths of this planet. Some of the most obvious effects were are having is on the tropical rain forests and coral reefs. These two areas are some of the most biologically diverse areas on the planet and we affect them greatly through our activities. For example the Amazon has lost 17 % of its forest cover since the 1950's most of it due to an increase in cattle ranching.
With the losses of the Amazon and other forests like it causes an increase in carbon in the air which does two things.
- It raises the ambient temperature of the planet
- Carbon gets adsorbed by the ocean which cause the ocean to become more acidic.
The higher temperature on the planet and the acidification of the water are having a deleterious effect on the coral reefs of the world which require a delicate balance of conditions in order for them to survive.
The rain forests and coral reefs are just the tip of the biodiversity loss that were suffering on the Earth. But they are the poster children that get people all fluffed up and angry. But we can't forget about the other ecosystems as well that are affected by humans action.
- Wetlands- Over half of the lower 48's wetlands have been drained and converted to other uses.
- Prairies- Plowed under/overgrazed for agriculture to feed the 7 Billion + people that now exist on this planet.
- Boreal and Temperate Forests- Intensively managed for logging and recreation. Also where a majority of the US population lives in large cities and agricultural areas.
- Worlds Oceans- Polluted by plastic and over fished to point where many major fisheries today are running into issues.
- The list goes on....
What can we do to stop it?
That really is the million dollar question that has yet to be adequately answered by the scientific community. But you as a citizen do has some options if you are willing to use them. The best course of action is to go against the grain of modern society and economy. The society that tells you that bigger is better and more stuff is better than less stuff. The economy that directs you to spend your money on products like tropical woods and beef from South America. That want to to buy that gas guzzling SUV and go on the carbon producing road trip across the country.
To reduce the impact on the planet and biodiversity as a species we must first reduce impacts as an individual. To do that you must think small and think local. Some people believe that because we can build cars, fly planes and go into space that we are the smartest species to ever exist on the Earth. In a way they are absolutely right, we are the smartest species on the planet but I don't believe that we are yet wise enough to use the power that being the smartest has given us.
To quote a famous comic book character,
"With great power comes great responsibility"
So I don't about you, but I am going to try to be a little more responsible
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