The Vostok,
Antarctica
ice core
is a high altitude,
inland ice core.
It formed from snow,
that came from water vapor,
that came from all of the
Southern Hemisphere oceans,
so should represent the average
Southern Hemisphere temperature.
A Russian team
has been establishing
a chronology of deuterium
from snow-cores near the
Vostok, Antarctica station.
Deuterium (2H) concentrations
in ice cores are used as a proxy
of the temperature at the time
the ice formed.
Deuterium is a heavy hydrogen
isotope that is considered stable.
It does not decay.
The link below includes
an explanations of how it,
and other isotopes, are used
as temperature proxies
in ice cores:
The connection between deuterium
and atmospheric temperature:
(1)
Isotopic ratios of oxygen-18 (18O)
and deuterium (2H) in snowfall
are temperature-dependent.
A strong correlation exists
between the average temperature
and the average isotopic ratio
of 18O to 2H in precipitation.
Vostok ice cores
tell us two things:
(1)
At times it’s been hotter
in the past, and
(2)
At times temperatures
in the past have risen
at a faster rate
than they have
since the 1800’s.
Deuterium measurements
from 8 meters deep,
to 3,310 meters deep,
of the Vostok ice-core,
indicate the temperature
of the nearby atmosphere,
back to 421,000 BC.
Deuterium in the
most recent layers
of the Vostok Ice Cores
reveal no
unusual warming
in the past 8,000 years,
in spite of the CO2 rise
in the last century.
Marcott 2013 shows
temperatures dropping
-- a more than
a -1 degree C. drop
from 5000 BC
to about 1800,
while CO2 levels
barely changed.
From 1800-2000,
the Marcott 2013
reconstruction
shows only a
+0.2 degree C.
increase
in temperature
in spite of
over a 100+ ppm
increase in CO2.
CO2 rose from
a minimum level
of 180 ppm
in the Vostok
ice core record,
to 410ppm today,
with no significant
warming effect.
From the Vostok data,
our present climate
is about -2 ⁰C below
the warmest of the
last 420,000 years,
and about +6 ⁰C
above the coldest.
There is
strong evidence
from ice cores that
global temperature
drives the
CO2 level,
with a lag of
hundreds of years,
rather than the
atmospheric CO2
level driving the
global temperature,
as the global
warmunists
claim today.