If the earth warms, the sea level rises,
lighthouses all over the world must increase their heights,
do you think so ?
and all piers must be increased their height,
and All breakwaters must be increased their height,
Our grandchildren will discuss it ! :(
Globally sea level raised on 8cm for last 25 years
https://en.wikipedia.org/wiki/Sea_level_rise
I don't think this is major problem for navigational lights in general.