Malthus's Revenge

The graph above is, I admit, a bit weird. It comes from Brad DeLong by way of Paul Krugman and is meant to illustrate that, for the bulk of human history, the much-derided Thomas Malthus was right: Population growth consistently overwhelmed technological growth. As you can see from the clustering of purple boxes there, technology did not traditionally solve our problems. It merely kept us afloat. And sometimes, it barely did that. "We only think Malthus got it wrong because the two centuries he was wrong about were the two centuries that followed the publication of his work," writes Krugman. But his theory did a pretty good job explaining the first 58 centuries of human civilization.

Why am I talking about this? I spent some time today thinking about Brad Plumer's article asking whether the climate crisis can only be averted by massive technological breakthroughs. It's not a marginal viewpoint. Steven Chu, who now heads the Department of Energy, apparently believes it. We're going to need "technology that is game-changing, as opposed to merely incremental," he has said. We're going to need understandings of basic physics and chemistry that are "beyond our present reach."

We have, in ways that are pretty wonderful, a post-Malthusian attitude about technology. On some level, we trust that it will rescue us when necessary. We may not be able to predict the form of that rescue in advance. But in recent years, trusting that our knowledge will outpace our problems has been a pretty good bet. This has, I think, bred a certain background level of comfort with climate change. There are plenty who believe it a bad thing, but on some fundamental level, don't believe that really bad things still happen. We'll find a way out. We always do. If this were a television program, we're barely at the first commercial break.

And maybe that will prove true. Maybe the hydrogen breakthrough is just around the bend. There's no obvious reason to think otherwise. But it's worth remembering that for most of human history, our problems were at least as big as our brains, and technology rarely intervened to avert calamity. There's no iron law that human civilization can't be torn apart by catastrophe. It has happened before, as you can see on the part of the graph coinciding with the Black Death. It will likely happen again. Malthus could still be vindicated. So it's good to put policies in place that make a breakthrough on energy technology more likely. But it's probably not a safe idea to put such insufficient policies on carbon emissions in place that our real policy is to hope for an technological breakthrough.