The honest answer is : quite a lot !
This is mainly becuase they dont know as its new territory. I have been trawling through literature and cant find anything quantifiable .
So whats in the media ? Primarily that weather will become more extreme , how much- they dont say .
The major thing they don't say [ that I have found, anyway] is that there is a time lag in temperature rise so even if we stop CO2 emissions now, it will keep worsening till it reaches equilibrium .
How to interpret that time lag for the common person then , 'cos that's what we wanna know . I personally dont really want to know if polar bears become extinct........ if i have the choice of knowing if I myself, am going to be extinct/flooded/burnt out/famished/hydrothermed/whatever.
There are 2 things happening with global warming.
1. Ice coverings on earth are disappearing
2. Weather is changing
The first should take decades or centuries to be complete. Once done, the sea level will have risen around 100m . Hope your great grandkids like water ! Anyhow, a bit far into the future and we will have sorted stuff by then hopefully as the more pressing aspect will affect this
The second is to know what's happening in the nearer future. My feeling is because of this time lag, stuff is going to get worse, so I think it's fair to assume that what happens now as a freak, is to expect that annually . I realise this isn't scientific and very much a straw guess, but its something to work with
In addition as it gross weather patterns become more frequent , areas of earth will become uninhabitable as people realise what's happening. if you think thats far fetched then consider the fires in California and their frequency/ferocity as one example, there are many others.
So what can we do ?
Try to get politicians to take it more seriously than now . Unfortunately they all want whats best for their country... NOW and sod the 'then' part .
Dont we, as a species, need to grow up, and get countries to work to a common good? Yes,it would mean creating a world government, but is it possible.
I really hope it is, as I cant see any other solution ....