But thats the rub, the impacts are unknown. There's a real tendancy when discussing climate change to focus on temperature rises and how that impacts the developing world, at least as far as the UK media is concerned. This then feeds the narrative that we'll be OK as it's an over there problem. The truth is much less clear.
For example, we know climate change is having an impact on the gulf stream, we're observing it slowing down much faster than anticipated, and that will present issues for both sides of the Atlantic.
While it remains active and ocean temperatures rise the UK can expect to experience more frequent and more intense storms as well as increasingly variable weather patterns. That will lead (and already has) to increased and more wide-spread flooding, increases in crop failure (or at least in yeild), insurance increases (particularly for buildings), revenue slumps (for certain industries), etc, etc.
If we had a competent government we might be able to put in adaptation measures, but those would largely become useless if the gulf stream then stopped (which it may well do).
Should it stop, the UK will experience significant temperature reductions (even I'm the face of global temperatures rises elsewhere) and it may become drier, which will impact everything from our ability to grow food to our ability to remain warm.
I realise this has gotten way off track so to bring it back around at least a little bit to the topic of the thread.
The solution to dealing with climate change impacts, including displacement, isn't to put up walls and closer borders, it's to engage and collaborate with everyone as everyone is going to be impacted sooner or later.