In the past
800,000 years,
we've had
climate cycles
about 100,000
years long.
They are caused by changes
in planetary geometry.
We have learned
from Antarctic ice cores
that for the past 800,000 years
there have been regular periods
of major glaciation followed by
interglacial periods
in 100,000 year-cycles.
These cycles coincide with
the Milankovitch cycles
that are tied to the eccentricity
of the Earth’s orbit
and its axial tilt.
There is a strong correlation
between temperature
and the level of atmospheric CO2
during these successive glaciations.
But CO2 lagged temperature
by an average of 800 years
during the most recent
400,000-year period,
indicating that
temperature changes
were the cause
of CO2 level changes
Milankovitch cycles
are far more likely
to cause a change
in temperature
than a change in CO2.
And a change
in the temperature
is far more likely
to cause a change in CO2
due to outgassing of CO2
from the oceans
during warmer times
and absorption of CO2
during colder periods.
Yet climate alarmists
insist that CO2 levels
are now causing
the change in temperature.
Temperature has risen
at a steady slow rate
in Central England
since 1700,
yet human CO2 emissions
were not relevant until 1850
and were minor until 1940.
Roughly 10,000 years of each
100,000 year cycle is a
relatively warm "interglacial"
period.
We are in an interglacial period
now -- and it has lasted roughly
10,000 years.
In the mid-1970s,
some scientists
observed global cooling
from 1940 to 1975,
in spite of rising CO2.
They speculated that
the interglacial was ending
and a new "ice age"
was beginning.
And the colder weather
would be a disaster for
people living in
higher latitudes.
It was just 20,000
years earlier that
Chicago and Detroit
were covered by
up to a mile of ice, and
95% of Canada
was covered with ice too.
The ice had all melted
by roughly 10,000 years ago,
with no help
from carbon dioxide.
In the mid-1970's,
some scientists
got great attention in TIME,
Newsweek, and other
mainstream media,
with a claimed
global cooling threat,
-- the media is always looking
for a scary story.
At the time, few scientists made
long term climate predictions,
because wild guessing the future
climate is not real science.
Other scientists noticed how much
attention the global cooling predictors
got in the media, and many were jealous.
Within a few years,
there was
a larger percentage
of scientists
predicting warming
from CO2,
based on a theory
from 1896.
That 1896 theory
was based on
laboratory experiments
to prove CO2 was
a "greenhouse gas",
at least in closed system
experiments in a lab.
Adding CO2 to the air,
by burning fossil fuels,
would cause warming.
No one knew how much
warming CO2 would cause,
and that's still true today.
In the 1800's
there was no way
to measure the temperature
in the troposphere, where
greenhouse warming
takes place.
The 1896 guess was a lot
of global warming from CO2.
The same professor, in 1906,
scaled back his guess, and
also claimed that warming
would be good news,
by delaying dangerous cooling
after the interglacial ended.
His 1906 guess is similar
to a popular 1970's guess of the
effect of CO2
= moderate warming.
But ...
the actual warming
since 1950,
if you attribute
ALL the warming
since then to CO2,
( with no proof of that ),
is mild warming,
at a rate of only
+1 degree C.
in 200 years,
assuming CO2
in the air
continued rising
at +2 ppm per year
( or 133 years
for +1 degree C.,
at 3 ppm
CO2 growth
per year ).
The actual warming rate
since 1950 shows that
slowly rising CO2 levels
are harmless,
even if you blame
ALL warming on CO2
( which is
much more than
the UN's IPCC claims
-- they blame
"over 50%"
of the warming
since 1950
on humans,
not 100%.
with no
scientific proof
their number is
'in the ballpark'
of reality ).
I suppose 50%
is halfway between
the likely range
of 0% to 100%,
but that doesn't make
"over 50%" right !
But actual measured warming
does not matter to warmunists
-- they have claimed,
since the
1979 Charney Report,
that future CO2
greenhouse warming
will be triple the rate
of the actual warming
since 1950 !
Their 1979 wild guess
on the effect of CO2
is obviously wrong,
but they won't admit it !
A worst case estimate,
based on actual warming
since 1975, proves the
1979 wild guess is wrong.
Climate computer models
that have predicted
triple the actual warming
in the past 30 years,
proves the 1979 wild guess
is wrong.
But the 1979 wild guess
is predicted every year,
anyway ...
because in this modern
climate junk science,
contradictory data
do not matter.
Nothing claimed to be true
can ever be "falsified"
in climate junk science.