Newly identified tipping point for ice sheets could mean greater sea level rise | Glaciers

It's very, very, unlikely to be centuries. Scientists have been overly conservative for many reasons, including not spooking their academic institutions, not wanting to look hysterical wrong in front of their peers, simply being wrong, political pressure, not wanting to scare off donors etc, etc. They have underplayed the intensity of impacts and overplayed the timescales until those impacts will be felt. Thankfully, larger numbers are breaking cover every year (in part because it gets increasingly difficult to support the status quo with every broken climate record).

Personally, I think the political elite, who see themselves as simply smarter than the rest of us, have decided that all the really bad news is going to have to be drip fed to us for as long as possible, so that the public doesn't throw their hands up in despair, lose all faith in the system that makes the politicians' donors rich, and start furiously building guillotines instead of going to work.