Railway infrastructure is commonly built for a 100 year lifespan. Even if it is updated, many norms are grandfathered in. Changing that requires enourmous effort.
That aside, your 1950 date is rather populistic. It was absolutely not scientific consensus back then that climate would change like that. It was only in the 1970s that this changed. That was 50 years ago and yes, that is not an enourmous long timespan for reworking our entire infrastructure. The Netherlands for example needed that time to undo the car centric dogma back to a multimodal one. The harmonisation process for rail control systems in Europe is easily 2-3 decades in the making and will easily need another 1-2 decades to even cover most of the primary network.
The article is behind a paywall so I can't comment ton specifics but to think all the norms and all the infrastructure could be easily changed, is taking a few short cuts. Granted, a lot of things can be changed at much faster pace but then also at much higher cost and also much higher waste.
I am not saying one should not be serious about those changes, but nothing is gained from polemics.