✨🌈 Global warming creates rainbows you'll never see🌈💅

It's the best cultural ecosystem service!

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Will Climate Change increase the number of rainbows? Yes! But you’ll (probably) never see them.

Today we’re looking at “Global Rainbow Distribution Under Current and Future Climates” which predicts that, by 2100, Climate change will increase the number “global annual rainbow days” by 4 to 4.9%, with the greatest increase under a high emissions scenario. According to the authors, around 21-34% of earth’s landmass will have fewer rainbows in 2100, with 66-79% of landmass gaining rainbows.

On the one hand this is kind of awesome right? It’s like, even though the world will be getting hotter and less livable, at least there will be more rainbows? But, there’s a catch.

The new rainbow hotspots will mostly be in “high latitude, “high elevation regions with smaller human populations”. So, as the world is burning, there will be more rainbows, but only in places where almost nobody lives! 

This map from the paper (page 8) shows where rainbows will increase most by 2100, with red indicating increases and progressively darker shades of blue indicating areas where there will be fewer days with rainbows.

Which locations benefit most?

Siberia, Northern Canada, Tibet and Alaska will get lots of new rainbows, while Europe, Brazil, and parts of Africa will generally lose rainbows.

Some sleeper winners in all of this are Indonesia, Tibet, and Japan which in addition to already being beautiful today, are going to have even more rainbows in the future. The biggest losers are Brazil, Western Europe, and Southern Africa.

This study also inadvertently highlights an under appreciated and controversial aspect of climate change—Some nations including Canada, and especially Russia, will benefit from climate change, at least compared to everyone else. And as temperatures rise, Russia keeps making money pumping oil, while its crop yields are projected to grow.

What are the limitations of this study?

One limitation is that initial rainbow data was downloaded from Flickr, the photo sharing service, using the hashtag “rainbow” as the means of finding photos of rainbows, geolocating those photos, and then adding it to a dataset. The authors note that only the English word “rainbow” was used, which reduces the reach of such a search.

You can see that the geographic distribution of collected photographs (page 3) correlates highly with the US and Europe. I can’t tell for sure, but it seems the paper may have only six rainbow photos from all of China, which is geographically the third largest nation on earth if only land area is counted (It’s fourth, behind the USA, if water area is also counted).

These rainbow observations are then fed into several models, including predictions for the future climate. I am going to be blunt here; since this is a peer-reviewed study with a large total number of datapoints, I assume there is some predictive value here. I am also not an expert in this space. However, I would have loved to see more photographs or datapoints from non-Western sources, and it does seem like it would have been relatively easy to use Google translate for at least a couple major languages like Chinese, Arabic, and Spanish (and perhaps Russian), to get a bigger dataset. This is especially true given this paper has a whopping 14 co-authors, some of whom must speak some of these languages. (And if they had to find another co-author or two to do this, would it really make a big difference to increase the total number of authors to 16, or even 20?)

What did I like about this study?

I think we need more research like this, that mixes open-source data from people, scientific predictions and models (and rigor) and combines it into a fun and interesting paper. Companies like Instagram/Twitter/Flickr should make their data easily searchable and accessible to academics to do research like this. Overall, this paper is a big win, despite the limitations noted above.

One last thing: “Cultural Ecosystem Services”

This is an entire paper about rainbows, but they don’t include it as a keyword on the front page of the paper. But they do include “cultural ecosystem services”. Does anyone in real life see a rainbow and say “I am so glad we have this cultural ecosystem service.” Can you imagine going on a date with a professor, and you’re like, look! A rainbow! And she is like “I love this cultural ecosystem service!” 

That is a major relationship red flag.

I’m joking but, this last meta point is important and speaks to the different incentives that academics have when writing academic papers versus communicating to the public. Like, what journalist (or average person) in their right mind would even come up with the term “cultural ecosystem services”? You just couldn’t sell it in a newspaper or broadcast. Imagine saying that at a barbecue. People would think you were drunk.

But for an academic, having a fancy term like this 1) Could demonstrate that this is a complex issue which demands precise definitions, which 2) Makes those studying it look smart, increasing prestige.

I am not an expert on “cultural ecosystem services,” so I won’t pass judgement on this field specifically, but I do think large terms which appear to describe or encompass simple phenomena can turn some average people off to academic research. Again, I’m not saying that is good, but I think it’s probably true.

This is probably one reason why most people do not read academic papers, even though they are often freely available and quite interesting.

Who wrote the paper?

Today’s paper was written by 14 people (!!!) but Kimberly M. Carlson was named as the lead author. It was published in Global Environmental Change in 2022. Most importantly, the authors of this paper definitely love cultural ecosystem services (and I guess I do to, given I love rainbows)

Until next time!

Alex

Note: Although we launched The Studies Show months ago (check out our first episodes on Instagram, Youtube, or TikTok) I’d still love to know what you think. This show is the successor to several older projects I had and since this continues in the same spirit as these older newsletters, I’ve kept the same subscribers for this one. But if this doesn’t resonate with you, feel free to unsubscribe!

The Studies Show reviews interesting academic papers. Founded by journalist and PhD student Alexander Webb, it aims to spread important academic findings and examine new papers and ideas. Alexander has previously written for the New York Times, National Geographic, and Wired.