the best explanation for the 2023-2024 warming being way higher than should have been possible with this el niño is that 2020 international maritime regulations reduced ship SO2 emissions by 71%. this is contrary to IPCC estimates of aerosol cooling effect (via cloud formation and resultant increased albedo) being very low and fairly constant from 1970-2020, which appears to be inaccurate and based on faulty models not informed by cloud microphysics, and dramatically underestimated the amount of aerosol cooling that was going on. thus, the reduction of a fair portion of said aerosols had a similarly large effect. this is exceptionally relevant because it means the entire model had to be refitted to account for the new aerosol models, and the new model that accurately tracks the actual temperature observations indicates a global temperature sensitivity to atmospheric CO2 increase that is like 50% higher than the IPCC (previously) best estimate (which now fails to account for the 2023-2024 warming). if this is correct, and it probably is because 2024 was also extremely hot, the global average temperature anomaly will not fall below 1.5°C as previously predicted, and further warming will be at a steeper rate. according to this new model that the authors ran, warming will be enough to cause AMOC shutdown by midcentury. and if AMOC shuts down, warm waters will be trapped in the southern sea, potentially causing an irreversible melting of the west antarctic ice sheet (as previously happened during similar climate 150kya, around the time that AMOC shut down then), leading to a global sea level rise of several meters over the next 50-150 years and then unstoppable further coastline retreat over the next several centuries.

No, wanting to see the night sky isn't a twee retvrn to ghibli-ass take. It's not a matter of some anprim impulse to dismantle industrial society for ~nature aesthetics~, it's an extremely visible symptom of environmental degradation that gets downplayed because the externality seems trivial to most people: "Oh no, the night sky, what ever will we do without it."

But it actively disrupts light-sensitive circadian rhythms in plants and wildlife, which disrupts foraging patterns, reproductive and hibernation cycles, and contributes to wildlife population declines. It's not the major contributor to those declines, but it's an additional point of stress in an ecosystem already stressed by climate change and other forms of industrial pollution. And so much of it is wholly unnecessary.

I don't think people realize how far-reaching the problem is, either. That light isn't just confined to the places people use. You don't escape it by just taking the bus to the edge of town. That light carries, in some cases for hundreds of kilometers. Death Valley has some of the darkest skies in the US, and yet, the dome of light above Las Vegas is visible on the horizon over 250 km away! Anywhere within 50 km of a major urban center, just about anywhere in the world, never gets darker than a night under a full moon.

And this is very much a recent problem too. Before the switchover to LEDs, it was relatively expensive to light places. That meant actually accounting for the energy use and making sure it was being used where it was needed. That light was also warm-colored, so it didn't travel as far. With the decreased cost of lighting, it became standard to light places like daytime whenever they might be needed. Lighting didn't get safer, it just got more thoughtless.

The reason you see astronomy-types sounding the alarm most loudly is because they're the ones who have been seeing the full effects of light pollution and its encroachment on dark skies. It's a hobby for me too, but it's partly because I am a night owl who grew up in a small town with nothing else to do. I used to be able to clearly see the Milky Way horizon to horizon when I grew up in the mid-00s. The last time I visited about five years ago, I could only see it overhead. The population has fallen by like 10%, but the skies are brighter. I can tell when the college decided to leave the football stadium lights overnight. I can tell where the car dealerships that added overnight display lights are. I can even see when trucks with the fuckass LED light bars are coming over a hill from 5 km away.