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Wednesday, July 3, 2019

Dansgaard–Oeschger rapid warming events

Our planet has had 
natural climate change
for 4.5 billion years.

Climate alarmists would
have us believe natural
causes of climate change
became unimportant "noise"
during the 20th century,
for which their 
"scientific proof" is:
"Because we say so"?



There were times
with no ice on the poles,
and other times with 
ice glaciers covering
Canada, Chicago and 
Detroit ( which was just 
20,000 years ago ).

That's a large range
of climate variations
from natural causes.



The globally averaged 
temperature is claimed 
to be warmer by about 
+1.0 degrees C, 
or +1.5°F, from 1880 
to today. 

I don't accept those numbers.

I'm confident the global average
has changed, because it always
does.

The measurements were haphazard,
with most thermometers in the 1800's
reading low, almost no Southern 
Hemisphere data before 1920, 
far too few Southern Hemisphere 
data before 1950, and far from 
global coverage, even today.

I can accept the global average
temperature increased since 1880,
since there's no evidence
that it decreased.

But, with honest margins of error,
not the ridiculous +/- 0.1 degrees C.
that is claimed, the global average
temperature change since 1880
could range from unchanged,
to +2 degrees C.

The rising temperature before 1950 
was considered natural climate
change.

The UN's IPCC 
claims "over 50%"
of the warming 
after 1950 was 
man made -- in fact, 
there is no evidence 
any of that warming 
was man made
-- it could have been 
100% natural.

Outside the IPCC, 
most climate 
alarmists claim
CO2 levels 
control the climate,
implying "100%", 
not just "over 50%". 




THE  ARCTIC
Arctic temperatures 
after 1990 rose two
to three times faster 
than the global average. 

Is that a climate crisis ?

Well, rapid Arctic warming 
has happened often before,
and naturally. 

During the last Ice Age, 
when CO2 concentrations 
were just half of today’s, 
25 abrupt warming events 
happened. 

Arctic temperatures rose 9°F,
and sometimes as much as 14°F 
in just 40 years. 

These rapid 
warming episodes 
are now called
Dansgaard–Oeschger 
events (D-O events) 
to honor researchers 
who detected them 
in Greenland’s ice cores.

Other than short term 
D-O events, and the
temporary effects of
sun blocking volcanoes,
there's no evidence of 
temperature changes 
averaging over plus or
minus one degree C.
per century

What could cause 
such abrupt D-O event 
warming ? 

Greenhouse gases 
or solar energy changes
could NOT cause 
such rapid warming. 

The best explanation 
is heat ventilating
from the Arctic Ocean, 
rapidly warming 
the nearby air.




Tropical Atlantic waters 
experience intense heating 
and evaporation. 

This results in warm salty water 
that is relatively dense. 

The Gulf Stream, and branching 
currents, transport that warm water 
northward. 

Because the water is salty, 
and dense, it sinks below colder 
and fresher surface waters 
as it approaches 
the Arctic Ocean. 

As a result, there's a layer of 
warm Atlantic water stored 
at depths between 
300 and 2,700 feet 
below the Arctic Ocean’s
surface, holding enough heat,
in total, to melt the Arctic
sea ice cover 
several times over.







Sea ice, and a layer of cold 
fresh water normally block
subsurface heat 
from ventilating 
to the atmosphere. 

If warm Atlantic Waters 
eventually melt the 
overlying ice cover,
the heat can vent. 

Or changes in 
Arctic wind direction 
can blow sea ice 
out into the Atlantic.

Without insulating ice,
a burst of heat 
ventilates from 
the ocean, and warms 
the atmosphere.




Recently, anthropologists 
studying past Arctic cultures 
found the pre-Dorsett culture 
periodically abandoned, 
then recolonized. 
the Arctic coast, 
as changes in sea ice 
affected temperatures. 

Such changes alternated
over several hundred years.

Is the Arctic still experiencing 
similar cyclical warming?




Dramatic Arctic warming 
during the 1920s and 1930s 
corresponded with increased 
intrusions of warm water, 
accompanied by Atlantic 
fish species normally found
further south.

The 1922 newspaper article below
reveals warming of the Arctic 
was so dramatic it raised concerns
 the frigid Arctic would soon be 
converted to a warmer 

“temperate zone”.










Warm water inflows began retreating 
around 1950, along with the Atlantic fish. 

Sea ice increased.  

Such cycles have been recorded 
in fishery data for hundreds of years. 





If the loss of Arctic sea ice, 
and warmer temperatures, 
are due to rising CO2,
we should be approaching 
a total loss of Arctic sea ice.

But the Arctic sea ice extent
has actually been steady 
for the past 13 years !





if natural oscillations are controlling
intrusions of warm Atlantic waters, 
Arctic sea ice will soon rebound. 

Because natural climate cycles
predict Arctic temperatures 
will NOT experience 
further warming,
or accelerated warming.

Based on earlier 
20th century patterns, 
such as when lost sea ice 
rebounded in the 1960s 
and 70s, Arctic sea ice 
should begin rebounding
in the future.