How serious can it be if according to NASA over the 20,000 years prior to today, the average loss in ice mass in Antarctica was equivalent to a 0.5 mm increase in the sea level each year ... more than the 0.4 mm increase claimed using the GRACE data? How serious could the loss of ice be if it's going to take 750 years to raise the sea level one foot.
Twenty thousand years ago was the last glacial maximum. Ice-caps kilometres deep over the Pennines, glaciers in the Pyrenees, Argentina and Oregon under ice. The absolute maximum amount of ice between the interglacials. That's your chosen starting point.
Between then and now came the transition to an inter-glacial. That's your chosen end-point.
There's a big difference between a glacial maximum and an inter-glacial, I'm sure you'll agree. Most of the change in ice-mass takes place over a few thousand years, but that's incidental. All in all, a lot of ice melts between a glacial maximum and in inter-glacial, most of it, this time around, over a few thousand years around the tipping-point.
From this you divide by twenty thousand and get an average, everyday sea-level rise for that period. 0.5mm per annum, that's what to expect. It's statistically accurate. Over the last twenty thousand years. Which is comforting.
So a thousand years ago sea-level was half a metre lower than today, and two thousand years ago the Romans would have been building harbours according to a sea-level one metre lower, four thousand years ago the Minoans would have lived with a two metre deficit. If their own experience didn't bear this out, that's probably because they didn't understand statistics.
Do the same thing with the
current sea-level rise of about 0.3mm per annum and the results are just as silly. You've smoothed off twenty thousand years, during most of which agriculture hadn't been invented, to compare with the last few decades. AGW is what's happening now, it's a new phaenomenon, it is significant, and there is no refuge in the past.
And what about the huge uncertainty in that estimate? There are uncertainties in that estimate because to make it they had to make assumptions. Will you acknowledge those uncertainties?
I could reduce my 0.3mm per annum estimate to 0.25 and it would still be significant as an average over recorded history. No such significance is evident.
A second even more recent study that I referenced claims satellite data shows an overall loss of ice so small that it would take 3800 years to raise the sea level even one foot. If true, is that something to get excited about and pass draconian tax legislation crippling our economy RIGHT NOW???
I'd drop the capitals if I were you, it smacks of alarmism.
And finally, will you apologize for Al Gore and the global walarmists who had claimed antarctic ice was decreasing even at a time when study after study said the opposite?
Well, we had to finish with Al Gore and the invented word to make you feel "cool" with the "in-group". (Courtesy of robinson, IIRC.)