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Climate Realism, El Niño, and Overshoot

Climate Realism, El Niño, and Overshoot

There was an article on Wired a few weeks ago that sounded the alarm about El Niño re: our current temperatures and the average global increase in temperatures that El Niño visits upon us. The conceit was, if we're looking at one of the hottest years on record this year–in a La Niña year–then we're really in for it when the switch is made to El Niño. This has been corroborated more recently by other outlets and forecasters, showing El Niño resurfacing at the end of this year. And while it's true that El Niño does and will increase average temperatures–and likely push us over an increase of 1.5°C for the first time, it's not all that it appears on its face. Though I'm generally trying to sound the alarm on all of this sort of thing, and generally encourage all alarm-sounders, there is an inaccuracy here that I think is important to point out.

So today, let's put on our science goggles and take as realistic a look as possible at just how screwed we are. Because we are, still. Just not exactly the way the folks at Wired (and elsewhere) may think. We are facing some serious problems, but El Niño isn't one of the bigger ones.

The Pacific Ocean is a Big Place

First, let's talk about ENSO: the El Niño-Southern Oscillation. El Niño isn't just some event that happens out of the blue–it's part of a pattern of three phases. ENSO is a mostly atmospheric phenomenon caused by changing wind patterns and ocean surface temperatures. There is no component of ENSO or El Niño which creates more heat in our global climate system; it is simply the cyclical change of heat which is already a part of that system. (It is also the single biggest cyclical change in our system, which means it is important regardless.) I emphasize this because I think it's an important point most articles about climate change/El Niño ignore. When they say we'll hit 1.5C next year because of El Niño, and the planet will be hotter generally, it's sort of like saying the climate will get hot in the summer–you're not wrong, but you're missing a key idea. Global surface temperatures do tend to increase during El Niño, in no small part because of how big the Pacific is and how much warm water is brought to the surface. But that heat energy was not created by El Niño–it's just been moved around. (Which isn't to say the authors thinks this is so–it's just not very clear and perhaps intentionally so.)

We are currently under La Niña conditions, which means the Pacific Ocean (or more accurately, a band of it) has cooler surface temperatures, but El Niño is not a big furnace that gets turned on in the ocean and heats things up. It is simply (very simply) the other side of the coin, with weather patterns shifted from one area to another. And while this does mean stronger storms for some areas, it means weaker or fewer for others. Despite what the Wired article says, by the way, El Niño is not an arbiter for increased Atlantic hurricanes–quite the opposite, as wind shear brought on by El Niño tends to stymie the creation of such storms. This cycle's La Niña, in fact, has made for plenty of disruption of its own, despite having less of a reputation for such things.

There is also a neutral period in the ENSO cycle, during which, as you might expect, things are pretty average. Which is a good entry point for our next idea: as with all things, climate change is gonna come knockin'. An El Niño or La Niña period is supposed to be relatively rare, at least on human timescales (approximately every twenty years), but climate change may push this cycle, creating such periods about twice as frequently as before. Predictably, the strength of these events is expected to increase as well.

Causes for Concern: Overshooting

I am for just about every and any outlet that wants to cover climate change in the right light. I appreciate that Wired, and the author of the article, took the time to put together a piece that would reach, perhaps, readers who wouldn't otherwise look at such a thing. And it does a fine job of delineating some of the very real problems that we're facing, even if the main conceit is a problematic one. In particular, this article serves as a good jumping off point for discussing what feels to me like the headline issue: the temporary (or not temporary) overshoot of 1.5°C.

A global increase of 1.5°C in temperature has been established as both a threshold and the goal for world governments. Commitments have been made that are supposed to help limit global warming to 1.5°C–though most of those commitments have not been kept. 1.5°C is also the point at which many scientists believe that warming will get away from us due to the knocking over of various tipping points, creating a vicious cycle that prevents humanity from getting any sort of lid on climate change. Some of these tipping points include the Greenland and Antarctic Ice Sheets, the slowdown of AMOC, and the death of the Amazon Rainforest.

The critical point in these articles is that El Niño pushes us over that 1.5°C line. But if it doesn't create heat energy–only moves it around–then we're already there, right? Kind of. Which is not exactly a headline to send you home with, but I think it's worth the verbiage. El Niño is a temporary exacerbation of an existing problem. I don't want anyone to think that because we're not in it right now, and won't be in it in a few years, (and maybe the temperature will drop below 1.5°C), that we're out of hot water, as it were. The truth of the matter is that, with or without El Niño, we're heading over 1.5°C.

We're already at roughly 1.2-1.36°C of warming.  Current IPCC estimates show us as temporarily overshooting 1.5°C, with "temporarily" doing a lot of work, and temperatures reaching 2-3.6°C–a high end estimate, but a devastating one. Research from the above link shows that in this scenario, the odds of one of four measured tipping points falling over the edge is roughly 1/3rd–which may seem like decent odds but really, really shouldn't. Think of it less like a one in three chance of some ice melting and more like a one in three chance that there's a nuclear war in twenty years. (Which may be true too, since we live in the worst timeline.) A study of temporary overshoots puts the long-term odds at an even-scarier 72%. Couple this with the potential that one of our tipping points may be breaking down already and, well. This is why you're reading the newsletter, isn't it?

The Present Isn't Looking Too Good, Either

While much of the impact of an overshoot will be in the future, we're already feeling quite a bit of hurt. The past few years have been filled with worrying news about the weather, and there is no recent exception. Just in the past few weeks, much of the continental United States suffered a blast from a polar vortex that dropped temperatures into the negatives, dumped ice and snow, and killed around 50 people–many of them in particularly hard-hit Buffalo, New York. A week after, temperatures in the east skyrocketed to an unseasonably balmy level and not long after a strong storm pushed through much of the South, dumping rain and raising the alarm for tornadoes. The West Coast has, for weeks, been lambasted by atmospheric rivers, dropping tons of rain and gusts of wind that have killed a few people and caused quite a bit of damage, with, as of this writing, more rain on the way. Climate change can potentially–almost certainly–exacerbate these atmospheric rivers.

There is no respite from these changes–nothing predictable, anyway. We may get a cool year, or a stormless year, a year without fires, but this does not indicate any halt in the pattern. The next year will bring floods, or droughts, the breakup of Thwaites or alarm bells from AMOC. El Niño may not do much of anything for or against us, but the certainty with which I can say things will get worse is of a gospel kind. There is no reason to be hyperbolic about climate change because the reality so frequently defies hyperbole.