All of Michael Hinge's Comments + Replies

Hi Ulrik,

I would agree with you there in large part, but I don't think that should necessarily reduce our estimate of the impact away from what I estimated above. 

For example, the Los Alamos team did far more detailed fire modelling vs Rutgers, but the end result is a model that seems to be unable to replicate real fire conditions in situations like Hiroshima, Dresden and Hamberg -> more detailed modeling isn't in itself a guarantee of accuracy.

However, the models we have are basing their estimates at least in part on empirical observations, which ... (read more)

2
Ulrik Horn
7mo
Hi Mike, in similar fashion to my other comment, I think in my pursuit of brevity I really missed underlining how important I think it is to guard against nuclear war.    I absolutely do not think models' shortcomings disprove nuclear winter. Instead, as you say, the lack of trust in modeling just increases the uncertainty, including of something much worse than what modelling shows. Thanks for letting me clarify! (and the mantra of more detailed models -> better accuracy is one I have seen first-hand touted but with really little to show for it, it is what details you include in the models that drove most of the impact in the models we dealt with which were about 30km x 30km x 5km and using a resolution of 20-200m)

Hi Ulrik, good to hear from you again!

We do not know what will happen if a nuclear weapon is again detonated offensively, other than that the world would be forever changed. This is a fear shared by pretty much everyone who deals with nuclear weaponry (including recent speeches at EAG London - such as John Gower, who we met before), and even without immediate retaliation the expected probability of a large scale future exchange would rise hugely in such a world. That's what I meant about the "all bets are off" line.

Certainly, many countries would seek to a... (read more)

1
Ulrik Horn
7mo
Yeah, I only meant to share some data as it seemed relevant, not to take a personal stance. And I think your point on more nation states acquiring nuclear weapons after a first detonation is a really good one and one that is not captured by the Metaculus questions I referred to.  Just to be clear: I think avoiding a nuclear war is important and neglected (unfortunately I am less sure about tractability but it should still be pursued). Both the recent nuclear sabre rattling of Putin, the increase in Chinese stockpiles (along with increased US-China tensions) and the withdrawal of the MacArthur foundation from funding disarmament are terrible signs and make me worry about the future. I even applied to a job here at Stockholm-based SIPRI in part because of my worries both about great power conflict and large-scale nuclear wars.

I feel there are a few things here:

  • Los Alamos claims that they are being pessimistic, but then end up with very low soot conditions compared to observations.
  • They claim that firestorms are difficult to form with 15kt weapons. If their logic holds this may be accurate, due to the circle of blast damage nearly overlapping with the circle of fire damage (see the map above), but that wouldn't be the case as weapons get larger (see the 100kt + weapon circles). This makes their conclusion less relevant for larger exchanges.
  • Their claimed soot lofting in the 72.6 g
... (read more)
2
Vasco Grilo
7mo
Thanks for clarifying! Which observations do we have? I did not find the source for the 0.02 Tg emitted in Hiroshima you mentioned. I suspect it was estimated assuming a certain fuel load and burned area, which would arguably not count as an observation. I cannot read how much soot is in the photo, so I do not know whether it is evidence for/against the 72.62 g/cm^2 simulation of Reisner 2019. I very much agree it is a threat in expectation. On the other hand, I think it is plausible that Los Alamos is roughly correct in all of their modeling, and it all roughly holds for larger exchanges, so I would not be surprised if the climate shock was quite small even then. I welcome further research.

Quick responses Vasco!

The 3.2 Tg figure is their figure for the worst case scenario, based on 1 g/cm2 fuel loading. In their later paper they discuss this may be too high for a 1 g/cm2 scenario, as you say they mention that their soot conversion was set to be high for caution, and they could have it an order of magnitude or so lower, which Rutgers do.

However, this presents a bit of an issue for us in my calculations and factors. I'm comparing headline results there, and the 3.2 is the headline worst case result. It could be that they actually meant that th... (read more)

2
Vasco Grilo
7mo
Thanks for the reply! Would Los Alamos agree that is an issue? From Reisner 2019: BTW, where did the estimate of 0.02 Tg come from? I did not find it in Rodden 1965 searching for "0.02", "soot" and "carbon".

Hi Vasco

I'm not sure I follow this argument: almost all of the above were serious fires but not firestorms, meaning that they would not be expected to effectively inject soot. We did not see 100+ firestorms in WW2, and the firestorms we did see would not have been expected to generate a strong enough signal to clearly distinguish it from background climate noise. That section was simply discussing firestorms, and that they seem to present a channel to stratospheric soot?

Later on in the article I do discuss this, with both Rutgers and Lawrence Livermore highlighting that firestorms would inject a LOT more soot into the stratosphere as a percentage of total emitted.

2
Vasco Grilo
7mo
Thanks for the reply! Agreed. I pointed to Robock 2019 not to offer a counterargument, but to illustrate that validating the models based on historical evidence is hard. I think the estimates for the soot ejected into the stratosphere per emitted soot are: * From Los Alamos, 6.21 % (= 0.196/3.158), which I believe is implied by the results of Reisner 2018 (see Table 1 of Reisner 2019). I estimated it from the ratio between the 0.196 Tg of soot ejected into the stratosphere, and 3.158 Tg of emitted soot in the rubble case. Even for a fuel loading of 72.62 g/cm^2, it is 6.44 % (= 1.53/23.77). * From Colorado and Rutgers, 80 %, as supposed in Turco 2007. “We adopt a baseline value for the rainout parameter, R (the fraction of the smoke emission not removed), of 0.8, following Turco et al. (1990)”. From the header of Table 2 of Turco 1990, “the prompt soot removal efficiency is taken to be 20% (range of 10 to 25%)”, which does correspond to R = 0.8 (= 1 - 0.2). I am not sure Lawrence Livermore estimates the soot ejected into the stratosphere per emitted soot. From Wagman 2020, "BC [black carbon, i.e. soot] removal is not modeled in WRF, so 5 Tg BC is emitted from the fire in WRF and remains in the atmosphere throughout the simulation". It seems it only models the concentration of soot as a function of various types of injection (described in Table 2). I may be missing something.

Hi Daniel,

Sorry, I only just saw your comment!

I think Lysenko and Lysenkoism is completely fascinating, but kind of proves the quote above. 

Lysenko was a biologist of sorts whose falsified, confused and just invented results on plants supported Stalinist and Marxist thinking on how people are not innate but created by environments, and then got brought into GOSPLAN to bring these insights to the economy. This is not because there was a lack of brilliant economists initially, just that those Stalin had were either cringing on his party lines, hidden in... (read more)

Hi Ed!

One thing that falls potentially into all three categories of difficulty is food stocks/reserves, which is an issue with high relevance to exposure to shocks and food insecurity, but really hard to track. 

It's a tricky issue, but could really help many researchers inside and outside of EA to improve!

A few issues we have found which would be very useful to see developed are:

The USDA PSD and FAOSTAT both have estimates for crop year end, but as crop years do not line up effective stocks are higher than this figure. These results are based on a few... (read more)

There are EA groups working on food security as a system, such as ALLFED, however while some of the work looks at today's systems, much is concerned about future crop losses in the 5-10% range, up to nuclear winter and wars. It may be something to consider in the context of his tweet and your article, however it is more abstract than food aid today, more about designing ethical and resiliant ways to manufacture foods and the social systems needed to feed everyone in shocks - where the food equivalent of a bank run commonly occurs.

3
Garrison
2y
Candidly, I'm not super informed on global food insecurity and would try to avoid getting too bogged down in engaging deeply with Beasley's claim (which seems pretty unlikely to be true, as OP spelled out nicely). But if there is a good EA write up on the topic, I might be able to bone up while writing the piece (assuming it gets assigned).