Download Are we headed for global catastrophe in the coming century?

Global warming
and CO2―Are we
headed for
global catastrophe
in the coming
century?
Don J. Easterbrook
Is global warming real?
Global, N. Hemisphere temperature
 What
is the magnitude of present global
warming compared to global climate changes
that have occurred in the geologic past?
 Were past global climate changes caused by
changes in atmospheric CO2?
 What is the role of solar changes in global
climate changes?
 On
a recent TV documentary about global
warming, a climate modeler said:
“CO2 levels in the atmosphere have risen to record
heights and never before in the history of the earth
has climate changed as rapidly as in the past century,
proving that global warming is caused by
anthropogenic CO2.”
“Our civilization has never experienced any
environmental shift remotely similar to this. Today’s
climate pattern has existed throughout the entire
history of human civilization.” (Gore, 2006)
Increase in atmospheric CO2
Atmospheric CO2 emissions
CO2 cannot have been the cause of climatic warming
episodes prior to 1945 because atmospheric CO2
didn’t increase significantly until after 1945
▲ Multiple 25-30 year periods of alternating warm and cool
temperatures have occurred since the Little Ice Age (~1600
AD). Temperatures during the Little Ice Age were about 4° C
(~7° F) lower than present.
▲ ~ 80% of the CO2 from human activities was added to the air
after 1940, so these warming episodes had to be natural
fluctuations unrelated to anthropogenic atmospheric CO2.
Global temperatures rose 0.5° C (0.9 ° F) from 1890 to 1940, well before the sharp rise in
atmospheric CO2, so it couldn’t have been caused by CO2. Global temperatures dropped 0.5°
C (0.9 ° F) from early 1940s to 1977 at a time when atm. CO2 was soaring. Since 1890 only
about half of the global warming corresponds to elevated atm. CO2.
CO2 began to rise sharply in 1945, but global
temperatures declined for 30 years
10 episodes of global warming and cooling that
cannot have been caused by atmospheric CO2
10 episodes of global warming and cooling that
cannot have been caused by atmospheric CO2
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1. ~15,000 yrs ago, sudden climatic warming (~12° C; ~21° F)
caused dramatic melting of large Ice Age ice sheets
2. A few centuries later, temperatures plummeted (~11° ; ~20° F).
3. ~14,000 yrs ago, global temperatures increased (~4.5°C; ~8° F).
4. ~13,400 yrs ago, global temperatures plunged (~8°C; ~14° F)
5. ~13,200 yrs ago, global temperatures rose rapidly (~5°C; ~9° F)
6. 12,700 yrs ago global temperatures plunged sharply (~8°C; ~14°)
F) at the start of the Younger Dryas.
7. 11,500 yrs ago, global temperatures rose sharply (~12° C; ~21°F)
marking the end of the Younger Dryas.
8. 8,200 yrs ago, a sudden global cooling (~4° C; ~7° F) lasted a
few centuries.
9. ~1000 AD, global temperatures rose several degrees to begin the
Medieval Warm Period, which lasted a few centuries, then
~1230 AD dropped ~4°C (~7° F) in ~20 years.
10. ~1600 AD, global temperatures cooled several degrees at the
beginning of the Little Ice Age
Solar effects and climate change
Global climate changes
correlate well with
changes in:
1. Solar irradiance.
2. Numbers of sunspots.
3. Production of 10Be and
14C in the atmosphere
from radiation.
Solar effects and climate change
During each global climate change:
1. Changes in the rate of production of 10Be in
the upper atmosphere by radiation indicate
changes in radiation input.
2. Changes in the rate of production of 14C in
the upper atmosphere by radiation also
indicate changes in radiation input.
3. These changes correlate with changes in
numbers of sunspots and solar irradiance.
LITTLE ICE AGE
 Much
colder and wetter, ~4° cooler than present
 ~1300
AD, temp. dropped ~4° C (7° F ) in ~20 yrs
 Glaciers
advanced all over the world
 Massive
crop failures in Europe; ~1.5 million people
starved to death; Large population decline in Europe
 Wine
production dropped sharply
 Themes
 Violent
River in London froze over
storms, early snow, flooding
Few sunspots occurred during the Little Ice Age
Changes in 14C production rates correlate with
sunspot minimums and climate changes
Sunspots and changes in production rates of
10Be in the upper atmosphere
14C
production rates match sunspot variations
Solar irradiance, sunspots, and glacial advances (blue)
Global temperature change and sunspots
Solar irradiance variations correlate with
global temperature change
Glaciers on Mt. Baker show a recurring pattern of advance and retreat
that matches the Pacific Decadal Oscillation and variation in solar
irradiance
Easton Glacier, Mt. Baker (modified from Harper, 1993)
1940 to 1956
1956 to 1979
Coleman Glacier, Mt. Baker
1940 to 1947
(modified from Harper, 1993)
1947-1979
Comparison of glacial activity and N.Atlantic temp changes
Warm/cool cycles with constant atmospheric CO2
Predicted global temperature changes this century
Predicted global temperature changes
this century
Two checkpoints of the ICPP vs. Easterbrook projections: By 2010, ICPP
projects ~1° F warmer, Easterbrook slightly cooler. By 2040 ICPP projects
~2° F warmer, Easterbrook ~0.4° F cooler. After 2040, temp. rises again.
CONCLUSIONS
During these abrupt climate changes, CO2 was not a factor.
 Far more severe global warming in much shorter time has
occurred repeatedly in the geologic past.
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Global climate changes have coincided with changes in sunspot
activity, solar irradiance, and production rates of 14C and 10Be
25-30 yr. global warming/cooling phases during the past 4
centuries coincide with changes in solar irradiance.
A 30-yr global cooling period during accelerating CO2 levels
suggests that CO2 is not be the cause of global warming.
Projecting the global warming curve for the next century
suggests cooling from 2006 to ~2040, warming from 2040 to
~2075, and cooling from 2075 to 2100 with a total warming of
only ~0.3 degrees by 2100.
 Global temperatures rose 0.5° C (0.9 ° F) from 1890 to 1940, well
before the sharp rise in atmospheric CO2, so it couldn’t have been
caused by CO2.
 80% of atmospheric CO2 accumulated after the sharp rise in CO2
~1945, but temperatures for the next 30+ years cooled 0.5° C (0.9 ° F)
in the Northern Hemisphere and 0.2 ° C (0.4 ° F) instead of global
warming.
 10 times in the past 15,000 years, sudden warming of ~8-12° C
(~14-21° F) occurred in less than 100 years and could not have been
caused by anthropogenic CO2.
 Glaciers have recorded multiple 25-35 year warm/ cool cycles over
the past 400 years. Only the last one could possibly be attributed to
atmospheric CO2.
 During the Little Ice Age, temperatures dropped ~4° C (~7° F) in
~20 years. The global warming that has occurred since then could not
be due to atmospheric CO2.