There's very much a debate about the assumptions that went into the original nuclear winter work. Cities today have a lot more steel and concrete, and it's not clear if the heat necessary for high altitude plumes would form. AFAIK no one has definitively settled the matter, but it is something think tanks publish papers on occasionally.

> AFAIK no one has definitively settled the matter

I think we can be confident that the really definitive work on this subject hasn't happened yet -- thank heaven.

This is not without controversy (1), and as I understand the expected cause is not from the nuclear explosions but the fires caused by the bombs such as standard forest fires.

1. https://en.wikipedia.org/wiki/Nuclear_winter#Criticism_and_d...

Aerosols from very large forest fires do reach the stratosphere and linger for months or years and have short-term climate impact. Hard to imagine much of the northern hemisphere set ablaze by the blasts without there being such an impact.

I wish you were right, but autocratic leaders tend to ignore scientific warnings

I'm not sure why you needed to quantify autocratic. From what I have seen of democratic leaders, scientific warnings tend to enter their decision-making only when convenient.

“Even if you win, you lose.”

AKA The Putin Way.

The soot from fires can actually be quite damaging globally. Here's a paper from 2020 that used state of the art atmospheric and crop models to look at the effects of the firestorms that might arise if India and Pakistan exchanged 100 nukes (about 1/3 of their arsenals) each about the size of the bomb used on Hiroshima directed at each other's major population centers.

Here's a blog article about it [2].

Here's the abstract:

> A limited nuclear war between India and Pakistan could ignite fires large enough to emit more than 5 Tg of soot into the stratosphere. Climate model simulations have shown severe resulting climate perturbations with declines in global mean temperature by 1.8 °C and precipitation by 8%, for at least 5 y. Here we evaluate impacts for the global food system. Six harmonized state-of-the-art crop models show that global caloric production from maize, wheat, rice, and soybean falls by 13 (±1)%, 11 (±8)%, 3 (±5)%, and 17 (±2)% over 5 y. Total single-year losses of 12 (±4)% quadruple the largest observed historical anomaly and exceed impacts caused by historic droughts and volcanic eruptions. Colder temperatures drive losses more than changes in precipitation and solar radiation, leading to strongest impacts in temperate regions poleward of 30°N, including the United States, Europe, and China for 10 to 15 y. Integrated food trade network analyses show that domestic reserves and global trade can largely buffer the production anomaly in the first year. Persistent multiyear losses, however, would constrain domestic food availability and propagate to the Global South, especially to food-insecure countries. By year 5, maize and wheat availability would decrease by 13% globally and by more than 20% in 71 countries with a cumulative population of 1.3 billion people. In view of increasing instability in South Asia, this study shows that a regional conflict using <1% of the worldwide nuclear arsenal could have adverse consequences for global food security unmatched in modern history.

[1] https://www.pnas.org/doi/10.1073/pnas.1919049117

[2] https://news.climate.columbia.edu/2020/03/16/even-limited-in...

>While scary, this does make it less likely for a major nuclear power to ever use such a first strike. Even if you win, you lose.

Your conclusion doesn't follow. You're assuming that national leaders are rational: Putin's actions in Ukraine show that this is simply not something we can count on.

Personally, I think it's highly likely we're going to experience a major nuclear exchange in the next few decades or less, with all the horrors (including global starvation) that entails. It's apparent to me that humans are simply too stupid to keep a global society running without destroying themselves.

>less likely Before both world wars there were many who thought that war between modern powers could never happen because it was 'too dreadful'. That is, the leaders involved would avoid war. Well, we're witnesses latelu to that leaders do choose war.

I call it a scare-theory because there is meaningful debate about it and its main point, famine is already achieved by things that we know will occur. In a no BS nuclear exchange the hydrocarbons industry will cease to exist. This means no diesel for combines, no mass production of fertilizer, no power to keep fans on to cool broiler chickens. The clock on food production goes back to 1750-1800 for some time.

An available calorie reduction this fast means famine, nuclear winter or not. I think tangible consequences like this helps normal people to understand the risks of nuclear war more effectively than trying to explain nuclear winter.