although they can probably mitigate the effects by moving to one of their 500 houses that's in a safe zone
That's why they don't care.
Climate change hits the poorest first and hardest (see: hurricanes in the Caribbean and SEA).
Billionaires can fly in, enjoy the sunshine, fly out and not get a drop of water on their skin.
And they'll keep "outrunning" climate change on an individual level, and only feel it when it hurts their net worth*.
*
At which point, they'll just re-organize their investments to exploit clean energy subsidies and real estate wherever everyone is fleeing to when the coasts flood.