The Climate in Emergency

A weekly blog on science, news, and ideas related to climate change

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One Less Thing to Worry About

This is a repost from the original version of this blog–now, rewritten somewhat.

There are plenty of things to lie awake at night worrying about.

What if I lose my job?
What if I can’t pay my mortgage?
What if all my teeth fall out?

Some of these worries are sensible, as worries go (did I turn the oven off before I went to bed?) and some are less so (what if I just somehow don’t die of old age, so when the sun turns into a red giant and eats the planet, I’m still on it?). But be reassured that one thing you don’t to worry about is the possibility that we are all being held in bondage to intelligent machines, as the The Matrix movies.

Don’t get me wrong; if intelligent machines do take over the world, I wouldn’t trust them not to put us in bondage, but the thing of it is human beings make terrible batteries.

(If you have not seen “The Matrix” and want the first twenty minutes to be a surprise, don’t read any further. Go see the movie, then come back.

You ready?

In that trilogy, it turns out that what we know as reality is actually a virtual-reality program used to keep human minds busy while their bodies are used as a power source for intelligent computers. It seems that war has broken out between humans and the machines, and that because the machines were, at the time, solar-powered, humans “scorched the skies,” blotting out the sun somehow with permanent thunder-clouds. To survive, the machines plugged humanity into their power-grid, raising whole generations in little pink tanks, harvesting the heat and electrical power of millions of bodies. The living, we are told, are fed on the dead, a gruesome, unwitting, cannibalism.

The reason we don’t need to worry about this is the Second Law of Thermodynamics, which states that energy cannot be recycled. Every time energy changes form, some of it is lost. For example, say you make electricity by burning fuel to run a steam turbine and then use all of that electricity to boil water, you’re never going to be able to boil as much water as the original power plant did.

In other words, this

Won’t work (as the author of the comic well knows).

This is why perpetual motion machines don’t work; all systems need fresh influxes of energy or they wind down, inevitably. It’s also why a gas stove has a smaller ecological footprint than an electric stove, if the electricity is derived by burning gas.

Most people have heard of the Second Law of Thermodynamics, since it comes up in some high school or college science classes, and occasionally in discussions of creationism as well. It isn’t an obscure concept, but somehow we aren’t used to thinking of it as part of our own lives. Perhaps we’re so used to thinking of “energy” in a metaphoric or metaphysical sense that we forget energy is literal, too.

Just the be clear on this, feeding a human population on their own dead indefinitely is impossible because each time one human ate another, most of the energy in the body would be lost. A 150 pound human needs to eat more than 150 pounds of food over a lifetime. Without sunlight (which the world of The Matrix no longer gets) the entire biosphere would lose its influx of energy and grind to a halt. No energy for the machines to harvest, and no food for the few human freedom-fighters.

Obviously, The Matrix Trilogy wasn’t intended as a physics treatise, but for all fiction must obey an internally consistent set of rules or the plot gets hard to follow. If a movie has talking animals or flying people, that’s fine, but if these elements appear with no warning in the middle of an otherwise realistic movie, it’s jarring at best. That the unexplained violation of the laws of physics it The Matrix does not seem to have distracted many people is worrisome.

The Second Law of Thermodynamics is central to many conservation issues. For example, an apex predator living on the meat of smaller predators needs a huge amount of land—enough land to grow enough plant matter that after five steps of energy loss there is still enough fuel left to support a breeding population of active animals. Without a visceral understanding of energy flow, it’s hard to think clearly about how much land really needs to be set aside for large predators.

Humans are also large animals, and we need a certain amount of land to maintain ourselves. We not only consume energy by eating, but also for heating, transportation, and everything else. Although as humans we can get very creative with what we use energy for and where we use it, our activities are limited by the total amount of energy coming into the planet as sunlight, and also by the energy needs of the other components of the biosphere; if we use more energy than our ecosystem can spare, the ecosystem begins to collapse, becoming less stable and less complex. The reason that the Industrial Revolution saw such a dramatic increase in the power at our disposal was not that humans suddenly got smarter, but that we began borrowing energy from the past.

Fossil energy is exactly that; energy that fell on our planet’s surface and was harvested by plants millions of years ago. Using more energy than the sun gives us per year is only possible when we take energy that the sun gave us in the past. Except that energy is already doing something; that ancient sunlight is busy sequestering carbon. Appropriating that energy to drive to the grocery store inevitably changes the atmosphere. There is no avoiding the fact that the kind of energy use we have become accustomed to is warping our planet and is temporary. Environmental sustainability means using less energy, period.

But, at least you don’t have to worry about “The Matrix” anymore.


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Thanksgiving Yet to Come

“It’s that time of the year again,” warns a fairly cynical-sounding blogger, “when warmists try to think Thanksgiving and climate change.”

Well, yes; we want to be seasonal, don’t we?

And yes, there are linkages to be made. A brief Internet search on the subject yields two main narratives: Thanksgiving as an opportunity to talk about climate change and agriculture (as in turkeys could get more expensive as feed prices rise because of recurrent drought); and Thanksgiving as an opportunity to talk about communication (as in what you have to do with your climate-skeptic relatives). These are excellent points and I’m not going to try to make them all over again.

Instead, I want to talk about gratitude. I want to talk about abundance.

Have you ever thought it strange that we give thanks by eating a lot? If anything, American Thanksgiving sometimes seems more a celebration of greed and gluttony, with a perfunctory discussion of life’s blessings sometimes thrown in among the other topics of discussion at the dinner time. And yet, there is one thing that being surrounded by more food than one could possibly eat is good for; it brings home a sense of bounty, the reassurance that, no matter what, there will always be enough. And that is something to be thankful for.

It’s an illusion, of course. There is no such thing as an infinite resource; use enough of anything for long enough and eventually you will run out. Even renewable resources are only sustainable if you use them slowly enough that they can replenish themselves. We know from sad experience that it is indeed possible to run completely out of precious things that once seemed all but limitless. Passenger pigeons, for example. Ever more efficient harvesting techniques hide the extent to which our fisheries are depleted. Expensive extraction procedures, like deep-sea oil drilling and tar sands mining, are now economically competitive–the more accessible oil is mostly already gone. It’s not necessarily that humans don’t have enough food and water. As a general rule, famine is a distribution problem, not a production problem (so far). But we no longer have abundance, a planetary Thanksgiving table groaning with reassuring excess.

Want a visual of the problem? Check this out:

Humans already use more than the entire ecological product of the entire planet. That is possible because we are, in effect, spending planetary capital, reducing Earth’s total richness a little more every year.

I’m not trying to be gloomy for the sake of gloominess, I’m talking about the physics of the environmental crisis, the details of how the planet works. I’ve gone into detail on this before, but the basic idea is that the planet has an energy budget and that when part of the planet (e.g., us) exceeds this budget, the planet as a whole destabilizes. The biosphere actually shrinks and loses diversity. One way to describe global warming and all its awful permutations is as a complex system being pushed into an entropic state.

The bottom line is that there is no way to sustainability that does not involve radically reducing our resource use–and the longer we put off doing so, the more stringent a budget our descendents will have to keep. We got into this mess by treating the entire planet as a Thanksgiving feast that would never end, but the feast is over now, and has been for a long time.

Does that mean we shouldn’t celebrate Thanksgiving? Of course not.

Real, literal feasts are never actually about unlimited consumption. We know perfectly well that the Thanksgiving table may groan, but it’s not actually infinite. It just feels reassuringly infinite, and it is that feeling that is important. The illusion of physical abundance is a needed reminder of the truth of spiritual abundance–which is the actual point of the holiday, the thing we’re actually remembering to be thankful for today.

The psychological power of the illusion of abundance does not depend on vast resources, something families of limited means understand well. By saving up and looking for deals and cooking skillfully, it is possible to produce a sumptuous feast that feels abundant and actually sticks within a fairly modest budget. The spiritual value is accomplished, and nobody goes into debt.

That’s what we have to do as a species. We have to find a way to live within our ecological means–the first step is to get off fossil fuel–and yet work with what we have so skillfully that what we have feels like more than enough. By staying within a budget we can stop worrying about running out–a paradoxical but very real form of abundance. Then the planet will have a chance to heal. The biosphere will grow again. And it is possible, just possible, that our descendants will live to see a more bountiful feast than what we have.

And that will truly be something to be thankful for.