Tyrannosaurus rex. Climate change stopped him cold, along with thousands of other genera and... [+]
I guess so. I mean from a purely selfish viewpoint it would be a bummer not to have pretty trees, lovely fish and cool animals like hippopotami. I do appreciate that bacteria and cockroaches are super survivalists, but losing species that need pristine environments would make life less pleasing.
But is that just a luxury or a necessity for our survival?
There has always been a dynamic tension between humans and the rest of the ecosystem since we figured out that we could actually change our environment to suit ourselves. As much as Hurricane Sandy took our arrogance down a notch, it was still a small win for Nature. We’ll repopulate the destroyed areas faster than you can say “plague”.
But human effects can be permanent. A good example is an early large-scale industrial activity during the Iron Age that instigated the clear cutting of Britain for wood and charcoal to smelt iron. That clear-cutting resulted in the Moors. The Moors are stark and beautiful and you’d have thought the forests would just grow back in a thousand years, but not so.
The fragile ecological equilibrium that grew old growth forests after the last Ice Age was gone. The existing forest could maintain itself by generating its own microclimate, but a new arboreal forest could never be re-established in that region. So that was that.
The world’s population was still not much above 10 million at that time and the global effects were slight. As we grew to over 1 billion, however, that changed. Large-scale extinctions began to rise and we are now losing over 1,000 species per year.
Things have gotten so bad that we geologists actually recognize that the present Holocene epoch will be the largest extinction event in the planet’s history, surpassing even the late Permian when 90% of all marine species shuffled off their mortal coil.
There have been five super large extinction events in earth’s history:
- the end of the Ordovician period when over half of all genera disappeared 430 million years ago
- the devastating marine extinction in the Late Devonian period 360 million years ago that took 80% of all animal species
- the infamous Late Permian mass extinction 250 million years ago when 90% percent of marine species and 70% of land species died
- the Triassic 200 million years ago when half of all life perished
- the Cretaceous 65 million years ago when the dinosaurs’ rule came to an end.
These events were huge and changed life forever after. The major cause of these extinctions was some variation of climate change although the cause of each change was unique. Whether it’s astronomical changes in orbital path, unusually high volcanic activity, plate tectonic changes that allowed ice to accumulate into polar caps, or the rare large bolide impact, organisms can only take a small amount of variation in average climatic conditions in their neighborhood.
The Permian–Triassic extinction event (the Great Dying) may have been caused by release of methane... [+]
Just because climate change is natural doesn’t mean it’s good. It’s a very very bad thing for most anyone that is alive at the time.
This time, however, it’s a one-two-three punch. Human transport of non-native species around the globe and the resulting xenobiotic-induced extinctions of native fauna was the first insult to begin in earnest and is still accelerating with expanding global commerce.
But loss of habitat is the real permanent killer right now. Although a manicured back yard looks nice and alive, and squirrels might love it, native fauna don’t. Same with corn fields. Of course, most squirrels are xenobiotic cronies of humans.
And habitat loss doesn’t just mean cutting forests or plowing up meadows, it’s also polluting coastlines and rivers, acidifying the oceans, clearing mangrove swamps to put in shrimp farms. It’s change, and just by our very presence in an area, humans cause massive change.
But global warming will be the icing on the cake of this extinction event, preventing any real recovery of Earth’s life even if we suddenly decide we want things back the way they were. Obtaining Dodo Bird DNA from a well-preserved skeleton won’t bring the species back if it doesn’t have any habitat left.
We’ve learned from studying past extinctions that there is a cascading effect to these things. Huge losses in biodiversity lead to everything from food chain collapses to changes in soil conditions to changes in microclimates to changes in atmospheric and oceanic composition. It’s not that life itself goes extinct; it’s just that your species might not like what happens very much, and might find itself gone entirely.
The problem for humans is that we depend upon so many species for our food and air. A massive extinction event doesn’t care about the species that we need, so we better reverse this extinction trend or we’ll find ourselves extincted right along with the others.
In a bizarre way, this has all been about energy and population. In the old days when hunting was the only real way to get enough protein, it was all about Location! Location! Location! Then came agriculture, a huge energy boom from just understanding how plants grow.
New access to chemical energy from agriculture, followed by mechanical energy from tools and simple machines, and finally energy from electrical and thermal power after 1850, caused profound changes in the levels of energy available to humans relative to any other species.
And so our dominance began. And like bacteria in a petri dish, our population grew exponentially. The land needed to accommodate this horde grew as well, and the land needed to produce the energy to power these throngs grew, too. Other species’ habitat was bound to lose. And the effects on the Earth to provide this land and this energy have surpassed even the Big Five.
So the only way to dial things back, if that is even possible anymore, is to reduce the population, reduce the energy needed to support it, and reduce the area needed to provide energy to it. So now not just atmospheric effects like CO2 need to be factored, but areal footprint as well. The accompanying figure shows the relative footprints among the major energy sources for both CO2 and land area, and includes mining and distribution as well as generation.
The first thing to jump out is that fossil fuels have a huge carbon footprint. No surprise there. The second thing is that renewables have only a little carbon footprint, but have a huge land footprint. Somewhat surprising. Nuclear has neither. Big surprise!
Whether or not you think it is too late to stop or reverse this whole process, it would be very smart to decrease whatever we can, as fast as we can. Or don’t worry about it and just party on like it’s 1999. Evolution’s just a theory, right?
