Introduction
I guess my interest in climate change really started with the Live Earth concert thing this summer. Don't get me wrong: I wasn't inspired to "do my part" to prevent global warming. Rather, I was struck by the odd question: is global warming a bad thing and do I even want it to stop?
At the time, my questions were primarily philosophical: as a student of ethics, I was interested in the value claim that global warming was bad and ought to be stopped. You see, there are two claims that global warming activists must make: first, and most obviously, they must argue that global warming is actually occurring and is actually caused by human activities, and the second, and often ignored, is that global warming is a bad thing and ought to be stopped.
When I first discussed this idea with friends and family, they did have a strong counter-argument to my line of questioning: if global warming causes the sea level to rise, and the sea level rising causes cities to be destroyed, and if the destruction of cities is bad, then global warming must be bad. Clearly, they pointed out, we want to stop global warming to stop the disastrous effects it would have on human civilization.
Philosophical Quandary
When thinking about how to reply, I was reminded of an argument from a bioethics class I took: old age and death ("mortality") is a good thing, even if it causes bad things to occur. In other words, even though becoming frail, losing friends and family, and all the other bad things associated with mortality are bad, mortality itself is actually a good thing. In fact, it's an evolutionary adaptation that allowed us to grow and change and, ultimately, to improve our genetic code. If we weren't mortal, the pressure to reproduce would be profoundly lessened, along with the associated genetic mutations that lead to evolutionary changes. In other words, if we weren't mortal, we wouldn't have evolved into what we are.
This argument is a bit misleading. What it actually does is argue that one beneficial effect of mortality outweighs all of the harmful effects. Ultimately, it seems almost impossible to make any value judgment to something without compounding, or at least considering, its myriad of caused effects. Generally, the way we gauge whether something is good or bad is by thinking about how it affects us and the things we already know to be good or bad. Philosophical quandary about the latter part of this equation aside, it still leaves us with the challenge of global warming.
Aristotle argued that value is teleological; that is, it stems from something's purpose or intent. A knife is good if it embodies the purpose of being a knife: that is, being sharp, sturdy, cutting well, easy to grasp, etc. By this argument, we must ponder the purpose or intent of the earth's climate. One way to do this very thing is to determine the history of a thing. By examining how something once was and how it changed in the past, we can attempt to draw conclusions about how it ought to be or change in the future.
What was the earth's climate like, through its history? If I was going to find out whether or not global warming was a bad thing, I needed to understand more about global warming. My investigation for historical climate data brought me through a plethora of different scientific journals and websites, all of which said more or less the same thing: the earth is colder today than it is supposed to be.
What's fascinating is how so many websites can say the same thing in so many different ways. I was particularly struck by two websites: one claiming that the earth was mostly hot with occasional periods of glaciation, and the other claiming that the earth was cold with occasional inter-glacial periods of warmth. It turned out that the former was looking at the earth's entire history, back 4.6 billion years or so, and the latter was only interested in the last two million years. I realized that perspective really is everything, especially when it comes to trends in climate history. If you look at just the last one hundred years or so, the earth has definitely warmed considerably from 1880 to 2007. But that's because the earth has cooled considerably since 1300, and even more since the Climatic Optimum of the Holocene Epoch around 4000 BC.
History of the Earth's Climate
Unfortunately, I havn't found any good site with all the complete data, so I had to put all the bits and pieces together the hard way. If you'd like, I'll take you on a quick tour so you can see for yourself. First off, let's take a trip to the University of California 's Museum of Paleontology 's website. They have this nice graph of the various periods of the earth, which we sort of need to understand what's going on.
The next graph I want to point out is this one from the Paleomap project. It shows the average temperature of the earth, estimated from geological findings. Unfortunately, the graph isn't to scale. You'll notice the small bit on the bottom called Precambrian? Well, look back at the UCMP site with the list of the periods. Precambrian is from the formation of the earth, some 4.5 billion years ago, to about 543 million years ago, when multi-cellular life took shape. In other words, that little box on the bottom of the Paleomap graph represents a huge 4 billion chunk of the earth's history. Granted, we probably don't know much about that period of time, and if that little estimated squiggle was to scale, it'd extend 9 times the rest of the graph and that'd be rather boring.
So anyways, I'm going to toss out the first 4 billion years of the earth's formation as irrelevant to our discussion on climate, since it consisted of a highly toxic atmosphere in which single-celled life forms alone prospered. As animas, I think we can safely limit our concern to the animal-bearing atmosphere and its related climate periods. As it happens, this concern starts with the earth at an average global temperature of 22 degrees Celsius or about 71 and a half degrees Fahrenheit. Room temperature, if you will.
During this first hundred million years, from the Cambrian to the Ordovician periods, approximately 543 million years ago to 443 million years ago, the earth started at 22C and ended at its first ice age, near 12C. The actual climate information about the periods was not very well known, but there is one crucial fact about the earth in this period: during the Cambrian to the early Ordovician, there was no ice at the poles. In other words, the earth was warm enough that the oceans were wet all over. At the end of the Ordovician period, the mega-continent Gondwana made its way to the South Pole through continental drift. Once there, ice did form, and earth froze over.
Continental positioning is one of the many theories of ice age formation, as described on Wikipedia. When a continent sits at a polar ice cap, ice can build on top of it, become very thick, and in general suck a lot of water out of the rest of the world. In turn, this ice reflects the sun's rays back out to space, cooling the world further. This could account for this first ice age, and, if correct, this theory also accounts for our current ice gate, due to the position of Antarctica . The closure of the Arctic Ocean , bordered by American and Eurasian continents, could also contribute to this effect.
The earth then warmed up in the Silurian period, cooled in the Carboniferous, then warmed catastrophically in the Permian, leading to the greatest extinction known. What exactly caused the intense warming or the extinctions, I don't know. But at least according to the graph on the Paleomap site, that little blip at the end of the Paleozoic Era was as hot as the earth has ever been. That gives us two ice ages, one short blip lasting some 20 million years and a much longer period of iciness for some 60 million years. This is over a period of 300 million years, so the earth was hot for about three quarters of the Paleozoic Era.
The next major period, the Mesozoic Era, when the dinosaurs roamed, was pretty much entirely warm. There was a cooling period between the Jurassic and Cretaceous, but certainly not the ice ages that had come before. So the earth stayed mostly warm this entire 240 million year period, until the Pleistocene ice age, the one with which we ought to be most familiar. So for the 543 million years when animal life existed on Earth, it was, by far, a hot place, marked by three (and a half) ice ages.
All this is aptly summed up by PhysicalGeography.net as they introduce their section on climate change in the Holocene epoch, the last 10,000 or so years. A third of the way into this epoch, between 7000 and 5000 years ago (5,000 to 3,000 BC), the earth was the hottest it has been in the Holocene, a good degree or two (Celsius, of course) warmer than it is today. This is the period known as the Climatic Optimum.
It seems to be no coincidence that during this period of warmth, human civilization developed. With increased access to food and rich, fertile fields, humans were able to settle and grow abundant food. As this period waned, ancient civilizations also collapsed as people spread out and probably fought for control of waning resources. The earth warmed again in 750 BC until 150 BC, then cooled again, then warmed again from 900 to 1200, the period of the High Middle Ages. The world cooled until the late 1800s, and has since been on the rise.
Climate Change Today
This whole history lesson is meant to illustrate two key points: First, that the earth's ideal state is probably a lot warmer than it is today, so following the teleological principles of Aristotelian thinking, global warming is a good thing. Second, that perspective really is crucial to understanding global warming. When you look at a chart of global temperatures from 1880, when the cooling period known as the little ice age ended, to today, of course the earth has warmed up significantly. But if you extend the period all the way back to the beginning of the Holocene, we're actually just getting back on track to where we're supposed to be. And if you look at the big picture, of the history of the earth as it supported life, we're still in the deep chill.
So whn I ask myself is global warming a bad thing, I can't help but answer: No. Of course, because human perspective in general is so small, we're generally mired in the concept that the optimal world is the world as it is today. Somehow, people seem to think that the world as it is right now is the same world as it always has been. That the glaciers that we see receding in panic videos produced by the global warming propaganda machine have been there since the world formed and we're somehow destroying this infinitely ancient work of nature. But those glaciers are very new. They only formed in the last 0.04% of the world's history; only in the last 0.33% of the history of animal life. That's very recent! That means that for 99.67% of the history of the earth during which animals lived, those glaciers hadn't yet formed!
Humans are very adaptable beasts. The world will warm, the climate will change, many of our cities will become inhospitable but other regions will become habitable. We'll migrate around, rebuild, and continue to prosper. People really just need to cognitively realize how adaptable they are. When a city gets washed away by rising sea levels, people just need to pack up and move somewhere better. The whole mentality of preservation and reconstruction is foolishness. The sooner people realize this, the better off we'll all be, global warming or not.
The only real threat we face from global warming is the rapid rate of climate change. Normally, these processes take hundreds of thousands of years, not a few decades. If we do manage to warm the earth's mean temperature by 15 degrees in 100 years, I'm sure that'd be a really, really bad thing. But there's a real question about whether or not we actually can heat up the world, even if we wanted to.
Conclusion: It's not our fault
Consider this website. I think most of its conclusions are in poor judgment; they seem more concerned about the imminent doom of another ice age - a theory that worried the nation in the 70's, apparently - than providing hard facts about anything. Still, they seem to propose something I am willing to put good faith in: humans probably have far less impact on the state of the earth's climate than we would like to give ourselves credit for.
They claim, for example, that temperature measurements are mainly taken near urban areas, and these temperatures are not representative of the whole earth because of the effects of these urban centers. Whenever I turn on the TV, the temperature report is from the local airport, which is actually right smack dab in the city. It's accurate for giving me the temperature I feel in the city, but it sure isn't valid for the global temperature! You can't aggregate all the temperatures in the cities, say they've gone up ten degrees, and conclude from that data that the whole earth has warmed up any. That site claims that satellite data, which is more reliable of the earth as a whole, hasn't shown any significant global temperature changes in the last 18 years since they've been in operation. Now, that's a claim I'm inclined to believe.
Ultimately, and I suppose most ironically, my original intent to ignore the factual claims about global warming and simply question whether or not it is a bad thing has brought me full circle. Here I am, now questioning the factual claims about global warming. I don't question that the earth might be warming up, or that it might have warmed significantly in the last 120 years. What I do question is whether or not mankind is responsible for it. I don't have the answers yet; I don't think anyone does. But I encourage you to do your own research before embracing anyone's conclusions.
Comments, questions, and responses are welcome via email.
