Figure 1: The climate framework using EPICA Dome
C ice core temperature proxies.
Not exact matches
GISP2
ice core temperatures show that the arctic was 2 degrees
C warmer 6000 years ago, 2000 years ago and approximately the same
temperature 1000 years ago (with the Vikings).
Carbon dioxide measurements on Dome
C ice, focusing on the interval 390 to 650 kyr before present, bp (2,700 — 3,060 m) 4, confirmed the strong coupling between CO2 and Antarctic
temperature found1 in the Vostok
ice core for the past 420 kyr.
The
ice cores show that during the last million years, whenever the
temperature rose 10
C the CO2 rose from 180 ppmv to 280 ppmv, a rise of 100 ppmv.
C) However, since the
ice core record shows many instances where
temperatures reverse and drop while CO2 is still increasing and vice versa, it is evident that there are other (largely unknown) climate drivers that routinely overwhelm whatever effect CO2 has on
temperatures (positive feedback included).
Further, there is firm evidence that migration of CO2 isn't important in the Vostok and Dome
C ice cores over the past 800,000 years: each glacial / interglacial period shows the same ratio between
temperature and CO2 changes: about 8 ppmv/degr.
C.
Global solar irradiance reconstruction [48 — 50] and
ice -
core based sulfate (SO4) influx in the Northern Hemisphere [51] from volcanic activity (a); mean annual
temperature (MAT) reconstructions for the Northern Hemisphere [52], North America [29], and the American Southwest * expressed as anomalies based on 1961 — 1990
temperature averages (b); changes in ENSO - related variability based on El Junco diatom record [41], oxygen isotopes records from Palmyra [42], and the unified ENSO proxy [UEP; 23](
c); changes in PDSI variability for the American Southwest (d), and changes in winter precipitation variability as simulated by CESM model ensembles 2 to 5 [43].
23 Thousands of years ago
Temperature change (° c) Carbon dioxide (ppmv) Temperature Change through time Compares to the present temperature Current Level Atmospheric Carbon Dioxide Concentration and Temperature change Current Level 2100 CO2 Concentration in the atmosphere (Antarctic Ice Core) If nothing is done to slow greenhouse gas emissions... CO 2 concentrations will likely be more than 700 ppm by 2100 Global average temperatures projected to rise at 2.5 - 10.4 degrees If nothing is done to slow greenhouse gas emissions... CO 2 concentrations will likely be more than 700 ppm by 2100 Global average temperatures projected to rise at 2.5 - 1
Temperature change (°
c) Carbon dioxide (ppmv)
Temperature Change through time Compares to the present temperature Current Level Atmospheric Carbon Dioxide Concentration and Temperature change Current Level 2100 CO2 Concentration in the atmosphere (Antarctic Ice Core) If nothing is done to slow greenhouse gas emissions... CO 2 concentrations will likely be more than 700 ppm by 2100 Global average temperatures projected to rise at 2.5 - 10.4 degrees If nothing is done to slow greenhouse gas emissions... CO 2 concentrations will likely be more than 700 ppm by 2100 Global average temperatures projected to rise at 2.5 - 1
Temperature Change through time Compares to the present
temperature Current Level Atmospheric Carbon Dioxide Concentration and Temperature change Current Level 2100 CO2 Concentration in the atmosphere (Antarctic Ice Core) If nothing is done to slow greenhouse gas emissions... CO 2 concentrations will likely be more than 700 ppm by 2100 Global average temperatures projected to rise at 2.5 - 10.4 degrees If nothing is done to slow greenhouse gas emissions... CO 2 concentrations will likely be more than 700 ppm by 2100 Global average temperatures projected to rise at 2.5 - 1
temperature Current Level Atmospheric Carbon Dioxide Concentration and
Temperature change Current Level 2100 CO2 Concentration in the atmosphere (Antarctic Ice Core) If nothing is done to slow greenhouse gas emissions... CO 2 concentrations will likely be more than 700 ppm by 2100 Global average temperatures projected to rise at 2.5 - 10.4 degrees If nothing is done to slow greenhouse gas emissions... CO 2 concentrations will likely be more than 700 ppm by 2100 Global average temperatures projected to rise at 2.5 - 1
Temperature change Current Level 2100 CO2 Concentration in the atmosphere (Antarctic
Ice Core) If nothing is done to slow greenhouse gas emissions... CO 2 concentrations will likely be more than 700 ppm by 2100 Global average
temperatures projected to rise at 2.5 - 10.4 degrees If nothing is done to slow greenhouse gas emissions... CO 2 concentrations will likely be more than 700 ppm by 2100 Global average
temperatures projected to rise at 2.5 - 10.4 degrees
The Antarctic
Ice Core temperature (above) only shows a 2.0
C decline during the Younger Dryas but Greenland's (above) are 15.0
C. Greenland did experience more of a decline than Antarctica in this event but nowhere near these numbers.
A few additions: — While coastal
ice cores reflect the
temperatures of the nearby Southern Ocean (via dD and d18O proxies), the deep inland, high altitude,
ice cores of Vostok and Epica Dome
C reflect the ocean
temperatures for near the whole SH.
By comparing the atmospheric CO2 increase (note that since CO2 is well - mixed in the atmosphere, a single
ice core record can be used as an accurate representation for CO2 - Shakun et al. used the Antarctic EPICA Dome
C ice core for CO2 data) to these many different
temperature records, Shakun et al. are able to discern whether the CO2 increase led or lagged
temperature changes in various different geographic locations, and for the planet as a whole.
Anyway, if the problem was huge, then the oldest
ice cores should show a lower CO2 /
temperature ratio, which is not the case for either Vostok (420 kyr) or Dome
C (800 kyr).
Temperature is based on measurements of the isotopic content of water in the Dome
C ice core.
Table 1 summarizes mean variation rates of
temperature, sea level and GHG concentrations during (A) the last termination (19 — 10 kyr), (B) the Holocene (10 kyr to mid-19th century), (
C) mid-19th century to mid-1970s, and (D) mid-1970s to 2005, based on
ice core studies [2], IPCC - 2001 and IPCC - 2007 [3], NASA - GISS [4], CSIRO Marine and Atmospheric Research [5], UK Meteorological Office [6] datasets and science journals.
Ice core temperature reconstructions such as Dome C are based on the isotopic composition of the i
Ice core temperature reconstructions such as Dome
C are based on the isotopic composition of the
iceice.
The GISP2 Greenland
ice core shows that
temperatures in Greenland from 10,000 years ago to 1500 years ago were virtually all 1 to 2.5 degrees
C warmer than present with «normal» CO2 levels.
You really should consider what went into this — 2
ice core delta 18O records of dubious relationship to
temperature (one is cited as correlating with NW China
temperatures at r = 0.2 - 0.4), 3 tree ring series, one of which is a delta
C - 13 record of questionable climatic significance (to be generous).