This is not something with a "source" or a real academic answer. There are too many variables and long tail events.
Survival in some of the worst case climate change scenarios involves moving away from the equator where crop failure and extreme heat will occur.
It involves having good access to water, and ideally farmland as wars over resources and refugee migration accelerate.
Martial law of some kind would become a normalized thing in population centers as basic resources and commodities become more expensive. Seattle has a large military presence.
Seattle is positioned geographical well for these things. Being farther north alone is a huge benefit. The mountains of the west due to their proximity to the Pacific enable much more temperate climates than other port cities.
This all sounds reasonable but also anecdote. I'm curious if there are any analyses, studies, or anything other than PNWers' HN comments backing claims like these.
I don’t have sources readily available but I have looked at several climate change projection models for the US in the past to answer similar questions. There are a handful of locales in the US where the local climate doesn’t change much under most models and parameters. They behave almost like fixed points in a mathematical sense. Some of these fixed points are not anywhere you’d likely want to live, so that might not help much.
However, the Seattle region is one, and it already has a pleasant temperate climate. IIRC, the main expected change is that it will get more sun in the winter months, which would address the main criticism of Seattle’s weather.
Of course, these models could be wildly off, but to the extent we have such models Seattle is in an enviable position. While there are some regions that look like they will change for the better e.g. some arid regions will get substantially more rain, it is hard to predict the true impact of that change on those regions — that outcome might come with significant trade offs.
