Stop the sea
It will not k9ll you bob!!
The two advantages of living in dwelling built into the side of cliffs were at it was easy to defend and offered protection from winter weather.
protection from raiders
The cave keeps the solar heat contained inside during the winter.The top of the cliff keeps out rain and snow.
Well... fuel is BAD for the environment and it is not good for people. But fuel is good for you if you need to run a car or other fuel powered device.