Micro, macro, population they are all .....
What causes me doubt is time scale and measurement. Today we can measure temperatures and rainfall Globally to levels of accuracy not achievable even 50 years ago. Through various scientific disciplines we can back plot to earlier times and establish patterns but as we go further and further back so the time scales expand to even thousands of years.
I came across an environmental survey for the East African fibre network. It had no bearing on the climate change debate so its data was not intended to support any climate change position. Two figures stuck in my my mind 18,000 and 130 metres. The latter being the amount of sea level rise.
That is a uniform rise of 72 centimetres per century.
How does this compare to today's estimates?
Here is a snippet from a University of Plymouth study for Cornwall
Over that 18,000 years that average 72 cm is pretty close to 50-100.Sea level is presently forecast to rise by about 0.5m over the next 100 years. However, there is large uncertainty attached to this and it could easily be more than 1m over the same time-frame. If the latter proves to be true, prominent structures on the coastline -- such as the Watering Hole bar -- will be under severe threat within the next 60 years.
The problem in indeed population. Over the millennia, as sea levels change so would people move further inland. If you look at the Western Isles you can see how habitation has crept inland away from the coast and prevailing westerlies. Where you have high population growth there is less space for populations to move too. In some countries land ownership and restrictions prevent movement. In others a desire for a beach front property in defiance of nature is the problem.