Learning to Think at Climate Scale

Why intuitions fail us when thinking on a planetary scale.

I went to the Planetarium with my kids a few weeks ago. There’s nothing like a planetarium show to give you a jolting sense of the unimaginable scale of even just our local star cluster, let alone the Milky Way. And that’s before we get to the brain-mushifying scale of galaxy clusters, of which, again, there are an unimaginable number out there. Of course, I “knew” the Milky Way was genuinely humongous when I went in, and that a galaxy cluster is many zillions of times humongouser than that. It’s hard to feel it, though.

There’s an analogue here to earth climate.

Because the climate is not on a human scale. And neither is climate change.

In 2022 we dumped the equivalent of 53,786,038,900,000 kg. of CO2 into the atmosphere. That number is many orders of magnitude too big for our puny brains, which after all evolved to keep us procreating as we picked berries and scavenged for bone marrow in an African savannah.

Climate happens on a scale so impossibly vast, it defeats us. That’s no surprise: plenty of research shows intuition fails us when we deal with large numbers. Climate scale is just too big. And that has consequences for how we talk about it.

Faced with scales we cannot grasp, we end up fighting over trivial nonsense, like the carbon footprint of Taylor Swift’s jet. I think we can all intuit that a single jet is totally insignifficant on a planetary scale. What’s harder to grasp is that even genuinely enormous climate facts turn out to be pretty insignificant at climate scale.

Take the IRA, the Biden administration’s landmark climate bill. With a price tag running into the hundreds of billions of dollars, it is, by any reasonable estimation, massive. But what about at climate scale?

Well, let’s see. Recent work by a team of Princeton scientists estimates that the IRA could mean U.S. emissions fall as much as 48% below their 2005 level by 2035. That would mean a reduction of 3.4 billion tons of CO2 equivalent by 2035.

Which sounds like a lot. And it is a lot on a North American scale. But the climate doesn’t work at that scale.

The climate works at climate scale.

Globally, the 3.4 billion tons of greenhouse gas that the IRA may prevent by 2035 is about the same amount by which global emissions rose between 2016 and 2022 (from 50.3 billion tons to 53.8.)

That’s not to say the IRA wasn’t worth it. It’s worth it! It’s just to say that earth climate operates at a scale so vast, that even genuinely huge changes still won’t really move the needle.

That this bums us out, that it saps our sense of agency, is neither here nor there.

The climate works at climate scale.

Look, thinking at climate scale is hard. It gives me a headache. It can be despiriting. But if we’re going to think strategically about the climate, we have to think at climate scale. It’s the only scale that matters.

The more I think about it, the more I think this is where the real gap in our climate discourse is. We’re not short of climate discourse at the individual scale, or at the scale of a company, or an industry or a city, or even at the national scale.

Climate change, though, is global. The hoary old overused adjective is, for once, properly applied here. The climate couldn’t care less that its scale overwhelms us. If we’re to have any chance to have a proper public debate about it, we would do well to insist the debate happens at climate scale.