Because of cultural reasons
Contour lines determine the steepness of the land by how close they are together. Generally, contour lines rise to a particular scale (e.g. a line for every ten metres), therefore, if the contour lines are closer together then the height of that particular area has risen more steeply than if the contour lines are further apart where the steepness has increased more gradually.
Well this is basically how I would explain this to him
There is really no reason to be worried this isn't a good thing but it ie also not a bad thing either basically the earths atmosphere is changing and the titonic plates are moving so the earths crust will recreate new states and make more islands like hawaii
Sunlight is the requirement of every single natural process on Earth.