In a recent Facebook thread, I was opining on the recent report that “Climate change could pose ‘existential threat’ by 2050” (Global warming could devastate civilization by 2050: report), saying that this really underlines what some people are saying–we have ten years to get our asses in gear. Maybe less than that. But if you read the report, a lot of it is about how climate problems (heat, drought, high seas) are going to put billions of people on the move away from home. There will be massive security concerns. I expect Trump’s call for a wall will seem a whisper in the wind. There will be many deaths from climate effects, but even more as nations defend their borders. My daughter remarked that “I am convinced this is correct. Giving voice to it makes one a Cassandra immediately. Most people just don’t know where to put that.”
The Cassandras have never been well received. Yet today, the developing climate crisis has spawned a considerable number of studies and reports, all delivering the same message that as we sail this bay in the sea of time, there are reefs ahead.
The warnings of doom go back to the 1860s, picked up steam in the mid-1900s, and have become almost commonplace today. There are two main reasons for the proliferation of doom-crying. First, our understanding of how the world works (science!) has increased tremendously. Second, we have developed techniques to express that understanding in ways that permit us to look some distance into the future. These techniques depend utterly on the computer and our ability to construct computer programs that incorporate what we understand of how the world works and then turn those programs loose upon the vast amounts of data we have been collecting. The result is an extension of historical trends (visible in all that data) into the future. The accuracy of the extension depends on how well we understand the world and is therefore subject to correction or improvement as our understanding improves. It also improves as our computers get better.
These programs are computer simulations. Since the nuclear industry refers to such simulations as “computer codes,” the title of this essay is “The Cassandra Code.”
Cassandra herself was a daughter of King Priam and Queen Hecuba of Troy. She was cursed to utter prophecies that would come true but no one would believe. The modern Cassandra codes are not quite so cursed. They are often maligned by critics, who say such things as “They’re just computer programs! They can’t know the future!” and “They just say what they’re programmed to say! Garbage in, garbage out!” and “But you have to oversimplify too much to put it in the computer!” But they have scored some notable successes, as when they were used to simulate the effects of putting megatons of crap in the air (as by nuclear weapons). The result is rapid chilling of the global climate, which gave rise to the term “nuclear winter” and made it clear that a nuclear war involving as few as a hundred warheads could have no winner. This led to the end of the Cold War and the threat of nuclear Armageddon under which I grew up.
They scored another win when they showed that adding chlorofluorocarbons (CFCs) to the atmosphere was destroying stratospheric ozone, creating an “ozone hole,” and increasing the risks of skin cancer, cataracts, and other ills. They also said that if we could stop doing that, the ozone hole would begin to recover and the risks decline, and once the world’s nations signed the Montreal Protocol and banned CFCs, that’s what happened. (Although recent reports reveal that factories in China are pumping CFCs into the air again.)
Cassandra codes also sparked a long debate over the future of human civilization when, in 1972, The Limits to Growth was published. The point of the book was that trends visible in the data as of 1972, projected into the future by means of a computer simulation that was ludicrously simple by today’s standards, led to serious trouble in this century. To prevent that trouble would require reducing pollution (including carbon dioxide emissions), industrial development, and even population.
No one liked that news, and the book was vigorously attacked. But follow-up studies, each using another decade’s worth of data and improved computer simulations, have repeated the message over and over again. We have done nothing to change the trends. Therefore we have done nothing to ward off the trouble the simulations project. Today that trouble looks a lot like the existential impact of global warming.
A critical question is “Why have we done nothing to ward off the trouble the simulations project?” If we put it another way, it becomes “Why could the Cassandra codes succeed in the cases of nuclear weapons and CFCs but not in the case of global warming?”
I put it to you that most national and military leaders did not really want nuclear weapons. As World War II showed, they were overkill. But the logic of mutual assured destruction (MAD) meant that if your rival had them, you had to have them too. The existential threat of nuclear winter gave everyone an excuse to back off and then sigh in relief.
People wanted CFCs. They were in refrigerators and air conditioners. They put the Pssstt! In aerosol cans. They had industrial applications. But they were not essential to anyone–alternatives existed. It was relatively easy for everyone to agree to do the right thing.
Global warming seems to be a different matter. Since it is due in large part to increasing amounts of carbon emissions (largely from burning fossil fuels such as coal, oil, and natural gas) and clearing of land (removing trees that pull carbon dioxide out of the air), we have known for decades what to do: STOP DOING THAT!
But we need the energy we get by burning fossil fuels. We need electricity for our lights, air conditioners, and computers. We need our cars. We love central heating. But people make huge amounts of money from doing things the ways we always have. The energy companies and the politicians they bankroll will give up fossil fuels only over their dead bodies.
Not that we would suffer if that happened. We have alternative energy technologies such as wind, solar, tidal, and geothermal. And the companies behind them are trying hard to become big enough to replace the big fossil fuel companies. But it is hard to make progress against entrenched giants.
We may need that existential threat of global warming. It doesn’t threaten a “nuclear winter,” but rather a hot “carbon summer.” If the message reaches enough people, the result may be similar to the end of the Cold War.
Unfortunately, I suspect that the carbon summer will have to become real, not just the anguished cry of a Cassandra code. By then, in another decade or so, it may well be too late.
Just as it was when the people of Troy ignored Cassandra’s warning that they really, really shouldn’t haul that big wooden horse inside the walls.