Ireland and Great Britain are at about the same latitude as Labrador in Canada, but benefit from heat transported across the North Atlantic from the Caribbean by warm water. Absent the current that is transporting that warm water, one would expect the GB climate to more closely resemble Labrador’s. In other words, much colder.
The problem is people mix up the overturning part of the AMOC and other overlapping streams.
And while the AMOC is powered quite a bit by water cooling down in the Arctic etc. the other streams are also to a huge degree powered by earth rotation AFIK.
In other words they won't stop, and likely won't slow down that much either. And that is if the AMOC stops instead of just slowing down quite a bit.
E.g. the rotation consisting of Gulf, Canary, N. Equatorial stream and N. Atlantic drift won't stop, but it will reach less far north and potentially colder. Similar for the other "rotations" like that (e.g. Brazil<->Africa) which the overturning stream overlaps with, through some parts might somewhat change their forms and water temperatures.
Or in other word while the absence of the AMOC can cool down GB/Ireland it won't remove all effects.
Expecting similar climate to other (coast) areas on the same latitude is ... not that useful. There are many different ocean current not affected by a stopping overturning current affecting the weather, additional even on coastal areas the wetter isn't always dominated by the ocean climate but can sometimes be largely affected by a constant strong weather front from the country side (both hotter and colder) and in some places that is a common occurrence due to the geography.
It still will likely be ... unpleasant in various ways.
not gonna lie, a scenario where a big nasty effect of climate change pastes Europe first might make the powers that be wake up to the impending disaster faster. For the folks with the big money one death in Europe might be more shocking than 100 deaths in India.
The trouble with climate change has always been that by the time you notice the "big nasty effect" it's already too late to prevent catastrophe.
To be clear, it's never too late to improve our fate, but by the time something like the AMOC shutting down destroys Europes climate, you've already signed up for an incredible amount of climate pain. Maybe such an event will wake us up enough to prevent out right extinction, but if this happened the collapse of industrial civilization would be virtually guaranteed.
Isn't that what this and other papers say - that AMOC is doomed to collapse, it's just a matter of time? I'm not sure I'd equate AMOC collapse to industrial civilization collapsing.
My understanding with climate change is that we have signed up for a lot already, but much more is on the way if we don't make big changes faster. Humanity is a crisis-motivated species. The trouble with climate change is the effects so far have nearly no impact on power. If AMOC were to shut down in 2030 devastating Europe's economy, that could be the wake-up call to everyone to actually stop fossil-burning ourselves to doom for short-term conveniences.
