Global warming won't result in near-extinction for humans. It will make life a lot less pleasant though, and will probably prove fatal to many in less-resilient (ie poorer) areas as food crops fail and prices rise. There will almost certainly be wars fought over access to water. Current global population levels will become unsustainable.
Some animal and plant species will certainly become extinct as habitats shrink, and ocean acidification will really hit a lot of food chains that we consider important (bye bye cheap protein from fish, already vulnerable due to overexploitation).
But you and me? We're part of the global elite, with the luxury of having the time and money to be posting on this site rather than scratching a living from subsistence farming. We'll pay higher prices for our food, and grumble about all the floods and tornadoes pushing up insurance premiums, but we're unlikely to die from starvation or war as a result of climate change.