Climate change is costing trillions — and low-income countries are paying the price?

Analysis of the effects of extreme heat shows that low-income, tropical countries have suffered the greatest financial losses, but is it true? Their source is Globally unequal effect of extreme heat on economic growth, which I will admit up front I don't understand, but since I blame them for writing a hard-to-understand paper rather than me for being stupid, that's not going to stop me posting. From this we see, roughly, that if you're hot you lose from warming and if cold, you gain. Astonishing. But wait, there is more. The vertical axis is "percentage points per SD of Tx5d", where Tx5d is something heatwavy.

How that reconciles with their later picture, which appears to show everyone losing, I don't quite know and couldn't be bothered to wade through finding out. If you know, do please comment¹.

They don't I think provide a numerical breakdown of damages but lower-figure B is a map of absolute values, and as you expect are larger where there is more GDP, and least in Africa, so no it is not true that low-income countries have suffered the greatest loses. At least, not the greatest absolute loses.

As to the size of the losses, they are not closely bounded, somewhere between $29.3 trillion and $5 trillion perhaps; perhaps $1 trillion per year, or approximately 1% of global GDP; global GDP has grown at approximately 3% / yr over that period.

As usual, we end up with conclusions like "Despite these caveats, our findings have important adaptation implications: Targeting resources at heat resilience and early-warning capabilities for only a few days per year may yield disproportionate economic benefits...". And yet what we really notice is that richer countries do better. If you're going to imagine interventions, why not "become richer", which has a wide range of other benefits as well, and can as Adam Smith pointed out quite some time ago be arranged by peace, easy taxes, and a tolerable administration of justice?

Notes

1. The paper says "The discrepancy occurs because our damages calculation incorporates changes in mean temperatures along with extremes, so climate change has modified the marginal effect of extremes alongside their magnitude and frequency. Warmer annual mean temperatures make extremes more harmful (Fig. 1), so anthropogenic increases in average temperatures make extreme heat become damaging even where it originally appeared beneficial" but I find this dubious, because the temperature changes over the period in question aren't large enough.

2. 2024/09: original image was https://www.science.org/cms/10.1126/sciadv.add3726/asset/0f180af1-fb50-4f61-9704-01f7f494b997/assets/images/large/sciadv.add3726-f1.jpg but the barstewards have moved it; I've updated it with what I hope is an equivalent. New is archived here.

Refs

* All Our Patent Are Belong To You (via Elon Musk Is Better Than You)

* A Letter to a Progressive With Poor Reading Comprehension (re Hutt, Liberalism, Majoritarianism)

* Food: GHG emissions across the supply chain (twit); original at Our World in Data.

* How the West fell out of love with economic growth - the Economist.

* Why did California go head over heels for equity? Aside from the political valence of it and the point at which American society was less than a year after George Floyd’s death, it is classic bikeshedding. Most people in civil society cannot develop, manufacture, distribute, or administer a vaccine. Decrying systemic racism, on the other hand, is quite accessible. We exhaustively train the entire professional-managerial class in doing it. Accordingly, official discussions of strategy for the vaccination effort quickly bent toward systemic racism. Lacking any ability to contribute regarding one pressing problem, many individuals of good will focused on the other - The story of VaccinateCA.