Weekly Letter to the President
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ofthisandthat.org. All rights
INAUGURATION, January 20, 2009
Drunk in its stale air
For two hundred years.
Fettered in mind and body,
The soul, the safe escape
To let me breathe the cries
Of my heart singing
Tears of mel-an-choly.
The tears flow free today
Washing the stains of blood
And sweat in brotherhood.
Raise the curtain then an'
Let the world look in
On this promised land --
We breathe free today.... almost.
--- Arshad M. Khan
We will be known forever by the tracks we leave.
--- Native American proverb
November 8, 2019 (posted November 18)
Mr. President: If humans have been lucky, basking in the comforting warmth of an
interglacial period for the last 10,000 years, that luck may be about to turn. Rest
assured we are not entering a glacial period.
No, our quest for greater comfort has us pumping fossil fuel residues in the air,
particularly CO2, warming the earth beyond its natural trajectory. One consequence
is melting Arctic and Greenland ice and coastal flooding.
Problematic as that might be, new research holds worse in store ... much worse, for
the Antarctic has not been a passive bystander. It melted when the north was taking
a rest allowing no let up.
The previous glacial age lasted from 125,000 to 118,000 years ago. A paper
published November 6, 2019 in Nature Communications (Vol. 10, Article # 5040) has
found the Greenland ice sheet melt insufficient to explain the highs of the rise then.
In fact it was the Antarctic ice sheet, previously thought to be inconsequential, that
was key. It turns out the Southern Ocean warmed first at the start of the interglacial,
leading to a change in the circulation pattern of the oceans and to a warming of the
northern polar areas to start the ice melt in Greenland.
Temperatures then were up to 1C higher than now but the same has been estimated
for us in the future. However, this time climate changes on earth have been
accelerated by greenhouse gas emissions over the industrial period, resulting in more
extreme climate changes than in the last interglacial.
The research has also revealed that ice melt caused a 10 meter sea level rise above
the present level at a rate of 3 meters (about 10 feet) per century, a rate that is 10
times higher than the rise observed in the last 150 years. If 10 ft. per century has a
remote feel, try a foot every 10 years!
This is far greater than current projections of sea level rise that anticipate an increase
at the most to about 3 feet above 2000 levels by 2100. The predictions, however, do
not account for an important natural outcome of ice sheet melt, that of ice cliff
instability. The ice cliffs form as the warm water melts their ice under the water, eating
away until the cliff shears off and collapses into the sea.
The collapse is a sudden and unpredictable addition to the gradual melt in the
ocean. It also means that polar ice sheet melt can affect sea levels far more intensely
than has been projected so far, and it could account at least in part for the much
higher rise found by the researchers in the prior interglacial. Are we in for a surprise!
If incoming solar radiation was greater in the last interglacial because of the earth's
position relative to the sun, the CO2 levels were lower, at 280 parts per million as
opposed to 410 plus today. Worse, in the former interglacial the two polar areas did
not warm up simultaneously. Today's intensive climate change is propelled by
greenhouse gases, and the warming is bipolar with the ice melting in both polar
regions at the same time.
Another paper also published in Nature Communications a week earlier (Vol. 10,
Article # 4844 October 29, 2019) examines global vulnerability to coastal flooding
from rising sea levels given new metrics for measuring land elevation. The model
currently in use for this measurement, developed by NASA, has a 2 meter vertical
bias. Using a new Coastal DEM (Digital Elevation Model) and a mean estimate of sea
level rise this century, the authors estimate 190 million people live below projected
high tide lines at present. This rises to 630 million by century's end in the extreme
case of high emissions. Increase the sea level rise to 3 meters (10 feet) projected in
the other paper above and a billion people could be in jeopardy.
What can one expect? Well, the first signs of trouble will be when coastal flooding
that used to happen once a decade becomes an annual event. The process is
gradual of course and our children, their children, and so on down the line will be the
victims of our legacy.