Climate Change and the Rate of Change
Climate Change and the Rate of Change
A Message From President Michael Bassis
The notion of time and speed as a significant variable is, I think, one that can be applied well beyond the issue of climate change. In education, for example, if we think that students have four years to learn what they need to know, then the college experience becomes very content driven. If, however, we think of learning as a life-long process, then the college experience should be designed with a great deal of emphasis on process--a focus on how to learn as well as what to learn.
That is part of the approach Westminster College has adopted. We believe it is our job to equip students with the skills they will need to keep learning long after they stop taking classes. For example, we believe that the purpose of a higher education involves more than having students analyze the literary worth of a book assigned in class--it ought to involve giving students the skills needed to analyze the worth of books they will read long after they graduate.
That observation has taken us far afield from Dr. Calvin's comments about climate change but that, I would submit, is a sign of the provocative nature of his remarks: he makes you think about what he had to say, and he encourages you to use his ideas to create connections between different concepts and create a more unified view of the world.
I have long believed that the rich, diverse, and vital conversations that take place on a college campus should be shared as widely as possible. We developed Westminster Matters in an effort to share some of those conversations with you. In this spirit, I hope you find Dr. Calvin's remarks to be thought provoking.
Climate Change And The Rate Of Change
Dr. William H. Calvin
This presentation was part of the Kim T. Adamson Endowed Lecture Series.
The overall theme of this address might be summarized in this way: how fast something happens really matters. We are always talking about the speed of one thing, the speed of another thing, and their speeds relative to each other. It is their relative speed that can create trouble--it's what tears apart materials as they expand at different rates.
It makes a big difference, particularly in climate and a civilization's evolution, if things happen slowly or quickly. For example, in military affairs in World War I there was this notion of a front line that shifted ever so slightly, back and forth, over months: a little advantage here, then a little disadvantage there. But by World War II, you had the notion of a Blitzkrieg where you punched through a line and disrupted an enemy's logistics. So, for example, the enemy might have his tanks, which are terribly dependent on fuel trucks to bring them more gasoline, at the front, but if you cut them off from their supply lines, they were trapped. So, that's an example of how speed matters. It matters in climate too.
By way of definition, consider "climate" as dealing with average aspects of weather. "Climate change" is about those averages changing. So climate is what you expect; weather is what you get. Normally we talk about "climate change" in terms of annual high temperatures, average rainfall, even the seasons when the rain falls.
There is a lot of variability in the record of climate. Temperatures drift downhill, the earth cools, and the amount of rainfall becomes less and less. In fact, cooling and drying normally go together on the larger climate scale even though on a weather scale they might not.
We once thought that climate change was gradual, but it turns out that's wrong. When, for example, we drilled two miles deep in Greenland from the top of the ice cap to bedrock and looked at core samples, we saw evidence that demonstrated that temperatures did fast jumps, methane levels shifted, and wind strengths changed dramatically. We found out the climate displayed a certain level of "flipness," a kind of dramatic alteration that we had not suspected before.
The surprises research revealed were, first, that you could have worldwide climate that changed dramatically within five to ten years, and, second, that gradual changes like an increase in greenhouse warming are quite capable of triggering rapid flips. That isn't typically what has happened in the past, but to the extent we understand the mechanism, it is clear that global warming can do that--a gradual change can produce dramatic climate shifts.
I suppose the other surprise is that even after 40 years of greenhouse warnings from scientists, we still have political denial in high places.
Most people think of global warming as a change in the thermostat. And you can see signs of that. Indeed Alaska, for example, has been experiencing warming: trees are getting rot and other diseases they had not been susceptible to in the past when the weather was cooler; shorelines are being eroded because there is no longer enough pack ice to protect them from waves. There are, in short, various indicators of change and, in fact, all the climate models have said for a long time that the high Canadian latitudes and Alaska were going to be the first places to get hit by global warming.
We blame global warming on greenhouse gases, but there is one gas you've probably never thought of in that context: water vapor or humidity. It's about 60% of the total greenhouse gases (carbon dioxide makes up a good part of the rest along with methane and others). Well, if something changes the average humidity, you get fairly rapid results from that. On a local scale, the difference between a clear and a cloudy night is something you immediately know because the cloudy night, in effect, forms something of a blanket that holds the heat in; when you don't have all that near-ground humidity, you can lose a lot of heat. So things that change water vapor are something to worry about because it's potentially so fast acting.
A gradual change will sometimes produce gradual results but sometimes things can get to a point where they tip over. I mean, if you're starting to pick up the edge of a table and you pick it up a little more, and a little more, and a little more--at some point everything slides off the table. And if you keep going, at some point the table flips.
Drought is the most familiar kind of climate change. You've had some around here. There is a sort of "slippery slope" involved in getting into a drought. More often than not, you get a drought through a series of events best explained as just random chance: the storm tracks just don't get into your area for a couple of years in a row, then a few hot weeks in summer really bake the topsoil that doesn't have too much moisture left in it to begin with, and the plants droop. The way you get out of it is chance again: a few years of rain restarts the vegetation but it can be a long time before you get kicked out of it; you need to have enough rain, more than average rainfall, at the right time.
There is a rather substantial problem related to drought that no one seems to be thinking of. It's a particular problem because in the last century our dependencies have changed. It used to be that about 38% of the people lived on farms and they knew how to grow food; and if there were a few bad years, there was a lot of slack in the system in the form of stockpiles and so on. Now we have an urban civilization where only 1.4% of the people live on farms--highly efficient farms, true, but their concentration actually makes the system more prone to collapse than it was a century ago. We have, for example, people living in cities at the end of a "just in time" supply line; they don't have much extra in terms of stockpiles. If anything severely disrupts the system, disrupts the transportation system, disrupts production itself as a result of drought for example, it is capable of causing mischief on a scale that just wasn't possible a century ago.
Are more droughts possible? Based on historic trends, if you were trying to do a little planning for what the 21st century may be like, you'd have to concede that there is a one in four chance of getting hit with a bad drought sometime in the next century. And if you relax the criteria--it doesn't have to be a century long, it doesn't have to be as widespread geographically--the chances are one in two.
And, of course, human behavior is making them even more probable. Consider the problem in terms of global warming. Basically, the rising temperatures have a critical impact on tropical waters which evaporate more as they get hotter and hotter. That means more humidity in the atmosphere, more greenhouse cover, more temperature spikes, and more evaporation. But what goes up as evaporation/humidity must come down, and it does come down in the form of rainfall, particularly as heavy rainfall concentrated in the higher latitudes. You might not think that rain over the oceans as a problem, and in 98% of the ocean surface it isn't, but at the higher latitudes heavy rainfall changes ocean currents and disrupts the Gulf Stream as well as altering wind circulation. The net effect is that as the North Atlantic currents fail and winds change, we flip from our present warm and wet mode to a cool, dry, windy, and dusty climate.
Europe will be the first to feel the effects of these changes because its climate is most directly influenced by the Atlantic currents and winds. Rough calculations suggest that 22 out of 23 Europeans will feel the effects directly and substantially. They will probably try to move elsewhere, but elsewhere will already be in trouble. The whole situation is a setup for the kind of drastic reduction in population which we have had via the Four Horsemen of the Apocalypse. You can have a series of rippling resource wars as nations try to take over the food supplies and resources of their neighbors. You can also have widespread disease and, as we now know from history, genocide has also been very common in such situations.
Unfortunately, self-insurance doesn't work in a situation like this. Normally, the West coast bails out the East coast for hurricanes, the East coast bails out the West for earthquakes, and the "cataclysmic" event is over in a day--recovery can start tomorrow. But these flips can happen quickly; they are worldwide, and since people everywhere are getting hit, you can't count on anyone bailing you out.
But this situation, while seemingly stark, depends on the speed of transition. A flip can take place in five to ten years, but suppose it takes 500 years? There is no doubt we could do all kinds of things in response: reduce population perhaps, make agriculture very much more efficient, build new roads and irrigation canals in places that get increased rainfall. But in a decline that takes just a decade, there isn't time to do any of those things. And while humanity, I think, would survive, the population that survived would probably be in a group of very small, authoritarian nations that hate their neighbors for very good reasons. This is the sort of situation that would take a very long time to recover from.
The main thing, then, is to avoid a lurch, a quick flip. The relative speed always counts. We can't do enough to compensate for a flip that takes place in five or ten years, which is where we are heading. We can, however, respond to and minimize the effects of a flip that takes place over a 500-year period.
Stuart Brand and The Whole Earth Catalogue had this wonderful phrase back in the '60s: "We may not be gods, but it is as if we were in terms of our impact on the world." So maybe we had better get good at this god business and adopt the kind of long-term responsibility needed to keep this show going. Certainly it is juvenile to assume someone else is going to pick up after us.
We have the ability to imagine the future, and imagine it in some detail with working computer models of oceanic and atmospheric circulation and the like. We have an ability to see further ahead, to see what is down the road. In terms of our ability to see trouble coming at us, we have a lot more going for us than the society of 100 years ago. We have gotten ourselves out of a lot of trouble because we saw where we were going. And if we can find decent ways to slow down a lot of these changes so we have 500 years instead of five years to deal with it, we might just be OK. But that depends on a lot of things that haven't happened...yet.