(Roughly) Daily

What is true of many blessings is also, Andrew Dessler explains, true of many curses…

If you’re struggling to understand why the impacts of climate change suddenly seem so awful, it’s time we discuss a key scientific term: non-linearity.

In a linear system, changes occur in a straight line. If climate impacts were linear, each 0.1°C increase in temperature would produce the same increment of damage. In this world, things slowly get worse over decades until, later this century, the accumulations of slow impacts becomes truly terrible.

But impacts of climate change are different — they are non-linear. In a rain event [as pictured above], for example, the first few inches of rain typically produce no damage because existing infrastructure (e.g., storm drains) were designed to handle that much rain.

As rainfall continues to intensify, however, it eventually exceeds the capacity of the storm runoff infrastructure and the neighborhood floods. You go from zero damage if the water stops half an inch below the front door of your house to tens of thousands of dollars of damage if the water rises one additional inch and flows into your house.

Thus, the correct mental model is not one of impacts slowly getting worse over decades. Rather, the correct way to understand climate change is that things are fine until they’re not, at which point they’re really terrible. And the system can go from “fine” to “terrible” in the blink of an eye.

The key to this is recognizing the thresholds that exist in the systems around us. For example, when engineers of the 20th century designed the infrastructure that we live with today (bridges, dams, storm runoff systems), they designed it for the range of climate conditions that existed at the time, adding in a small margin for unforeseen weather extremities. But not too much of a margin — they wanted to keep costs down.

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The speed of us passing limits is mind bending. People who are impacted are often shocked and we frequently see people bemoaning the fact that some impact never happened before — this is the calling card of non-linear effects…

Rain, snow, wind, heat– we’re living in a non-linear world: “Why are climate impacts escalating so quickly?“, from @AndrewDessler.

* Epictetus

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As we steel ourselves, we might recall that it was on this date in 1969 that Hurricane Camille, the 2nd most intense and one of only four Category 5 hurricanes to make landfall in the continental U.S., came ashore along the Mississippi Gulf Coast near Waveland, MS.

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