kokopelli wrote:
You do realize, don't you, that this is a cool period in the history of the Earth. Prior to the beginning of our current ice age, they were a fair bit higher than they are now.
OMG no! You are talking nonsense!
I mean, OK, if you are looking at the
entire history of the earth and geological periods of
hundreds of millions of years, then it is true the earth has cooled over time. But trends over hundreds of millions of years is not the relevant period to be looking at with respect to impact on our current civilisation!
In terms of climate fluctuations
since the birth of humanity, let's say over the last 200,000 years, the current level is not a cool period, it is an interglacial, which is a warm period.
This page from CSIRO
https://research.csiro.au/slrwavescoast/sea-level/sea-level-changes/#LongTermindicates that:
Quote:
Sea levels typically vary by over 100 metres during glacial-interglacial cycles as the major ice sheets wax and wane as a result of changes in summer solar radiation in high northern hemisphere latitudes.
So yes, I agree that sea levels
may have been a few metres higher at some point during the last interglacial, which was
between 130,000 and 115,000 years ago.
CSIRO again:
Quote:
Sea level has increased by more than 120 metres since the end of the last ice age.
So between 115,000 years ago and the present, sea levels
fell over 100 metres and rose again. So if we are looking at the history of humanity, sea levels are
higher now than they have ever been since our ancestors walked out of Africa.
And again:
Quote:
Sea level stabilised over the last few thousand years, and there was little change between about 1AD and 1800AD Sea level began to rise again in the 19th century and accelerated again in the early 20th century
If you are looking at the start of agriculture and civilisation, we are only talking about the last 10,000 years or so. Yes, this has ocurred during an interglacial (warm period) but it has actually been a period of
relative stability of sea level. One could equally argue that it is stability of sea level which has led to our current civilisation.
If you are looking at climate change in the perspective of
the entire history of the earth, you could
perhaps argue that warmer climate may have benefits to life in general over the long term.
But if you are looking at
the effects of climate change on human civilisation over the next few thousand years, your argument is completely nonsensical.