It’s a really bad idea to compare climate change to atomic bombs
Referring to ‘four Hiroshimas per second” does more harm than good
The folks over at Skeptical Science, a website that aims to explain climate science and combat the misinformation that often surrounds the topic in the mainstream media,have come up with a campaign that compares climate change to atomic bomb explosions.
The goal is to illustrate how much our climate is warming in terms that people understand. If you tell someone that the planet is accumulating heat at a rate of 2.5 x10^14 watts, they’ll look at you blankly. But, the thinking goes, if you tell them that’s equivalent to four of the bombs dropped in Hiroshima in 1945 every second, that tends to make eyes widen.
Here’s the thing, though. One of the most effective accusations made against those who favour emissions cuts is that they’re being “alarmist” — that things aren’t going to turn out anywhere near as bad as people say. In some cases, often when environmental activists are involved, that can be true. Climate scientists tend to be very careful with how they present their work for this reason — to avoid being accused of overhyping the risks.
Big Numbers
Declaring that we’re exploding four atomic bombs every second in our climate might be true from an energy transfer point of view, but the context necessary to understand that comparison is missing. The Earth gets heat from the Sun at a rate of around 2,800 bombs dropped on Hiroshima every second. About 24 Hiroshima bombs worth of heat are transferred by the Gulf Stream every second. We’re talking about a system that deals in very big numbers.
That doesn’t mean that the smaller numbers we deal with in climate change are less important, though. The balance of those big numbers turns out to be exactly the temperature that human society is designed for, and even the tiniest changes can dramatically upset that balance.
Unlike Hiroshima, the energy we’re accumulating won’t show its effects over a timescale of seconds or minutes. But unlike any climate change the Earth has experienced before, it won’t take place over tens of thousands of years either. Instead,climate scientists expect to see changes on a timescale of decades.
That’s slow enough that it won’t cause the devastation seen in Hiroshima in 1945, but it’s fast enough that the Earth’s ecosystems won’t be able to adapt in ways that they have in the past, causing a very different kind of inexorable slow-motion devastation, like being run over by a glacier.
Thinking about it in terms of atomic bombs isn’t at all helpful, and belittles the tragedy experienced by the residents of the city. A far better metaphor is the boiling frog, though that has factual inaccuracy issues — which aren’t helped by the fact that, like humans,frogs don’t tend to sit still in whatever temperature of water.
The Window Test
From a communications point of view, another major risk of comparing climate change to Hiroshima is raised by Warren Pearce on Nottingham University’s Making Science Public blog. He argues that it doesn’t pass “the window test” — adequately explaining the massive gap between the rhetoric of four Hiroshima bombs per second and what you can perceive looking out of your window. For the average person on the street to be persuaded by an analogy, it needs to be understandable in terms of what they see around them.
Pearce explains: “One might reach the opposite conclusion from that intended: that the Earth is actually quite resilient to such energy retention, and that four Hiroshimas per second isn’t anything to worry about.” He suggests that a better candidate is a bathtub. “One can argue about how big the bathtub is, the rate at which it is filling, and what happens when it overflows,” he says.
That’s less spectacular, of course, and won’t grab headlines. But neither does it fuel accusations of alarmism, and mislead the public into thinking the climate system is resilient enough to withstand the kind of change we anticipate.
So instead of throwing around wild, dramatic metaphors out of context, let’s just work on explaining the science as best we can. In the case of climate change, that science tends to speak for itself.
