United Nations' IPCC offers the "gold standard" climate change assessment. Their most recent report gave an avg estimate of 3.2 degrees of warming by 2100.

Last time the world was 3° hotter than pre-industrial levels, sea levels were 25m higher.

This is what 3° looks like for cities across the world: https://www.theguardian.com/cities/ng-interactive/2017/nov/03/three-degree-world-cities-drowned-global-warming

And (to "bring it home" for those who live near me) this is what 25m sea level rise looks like in S.E. England (from http://www.floodmap.net):