Title: Four Things I Think I Know About Climate
1Four Things I Think I Know About Climate
- John R. Christy
- University of Alabama in Huntsville
- Alabama State Climatologist
2We should always begin our scientific assessments
with the following statement At our present
level of ignorance, we think we know
Paraphrase of Richard Mallory Hoover High
School Fresno CA Physics Teacher 1968
3- Testing Hypothesis (assertions) about Climate
- UAHuntsville builds datasets from scratch
- Popular surface temperature datasets are poor
metrics for checking on the greenhouse effect -
and they are poorly measured as well - Warming is occurring but at a rate and in a
manner that is inconsistent with model
projections of enhanced greenhouse warming - Sensitivity research suggests the climate system
is less sensitive to CO2 increases as depicted in
models due to unaccounted-for negative cloud
feedbacks - 4. Impacts on global emissions of current
legislative actions are minuscule and will have
no discernable impact on whatever the climate is
going to do
4Testing Hypotheses on Global Warming1. Testing
Assertions based on Popular Surface Temperature
DatasetsPopular surface datasets tend to (a)
overstate the warming, and (b) serve as a poor
greenhouse metric
5CO2 up 38 at current rate of 0.6 per year
6Day vs. Night Surface Temp
Greenhouse signal
Warm air above inversion
Cold air near surface
Nighttime - disconnected shallow layer/inversion.
Temperature affected by land-use changes,
buildings, farming, etc.
Daytime - deep layer mixing, connected with
levels impacted by enhanced greenhouse effect
7Night Surface Temp
Warm air above inversion
Warm air
Cold air near surface
Buildings, heat releasing surfaces, aerosols,
greenhouse gases, etc. can disrupt the delicate
inversion, mixing warm air downward - affecting
TMin.
Nighttime - disconnected shallow layer/inversion.
But this situation can be sensitive to small
changes such as roughness or heat sources.
8MODIS 21 Jul 2002 Jacques Descloitres MODIS
Land Rapid Response Team NASA GSFC
9Nighttime temperatures rising but not because of
greenhouse gas warming, but nighttime readings
are included in popular datasets Daytime
temperatures tell more accurate story Christy
2002, Christy et al. 2006, 2007, 2009, Pielke et
al 2008, Walters et al. 2007
10Nighttime temperatures rising but not because of
greenhouse gas warming, but nighttime readings
are included in popular datasets Daytime
temperatures tell more accurate story Christy
2002, Christy et al. 2006, 2007, 2009, Pielke et
al 2008, Walters et al. 2007
111. (c) Some surface data sources are simply poor
12Kilimanjaro
13Kilimanjaro
14- Testing Hypothesis (assertions) about Climate
- UAHuntsville builds datasets from scratch
- Popular surface temperature datasets tend to be
poor metrics for checking on the greenhouse
effect - and they are often poorly measured as
well - Warming is occurring but at a rate and in a
manner that is inconsistent with model
projections of enhanced greenhouse warming - Sensitivity research indicates the climate system
is less sensitive to CO2 increases as depicted in
models due to unaccounted-for negative cloud
feedbacks - 4. Impacts on global emissions of current
legislative actions are minuscule and will have
no discernable impact on whatever the climate is
going to do
15Testing Hypotheses on Global Warming2. (a)
Testing Assertions based on Climate Models for
global trend magnitudeClimate models tend to
overstate or misrepresent the warming
16Predictions
17Predictions
Observations
18G. Schmidt NASA/GISS
19Individual Model Surface Trends 1979-2010
20Trends ending in 2008 with various start
years IPCC AR4 Model Runs (22 models) vs. Obs.
Start Year
21Trends ending in 2008 with various start
years IPCC AR4 Model Runs (22 models) vs. Obs.
Start Year
22Trends ending in 2010 (Jun) with various start
years IPCC AR4 Model Runs (22 models) vs. Obs.
Start Year
23Global Bulk Atmospheric Temperatures UAH
Satellite Data
Warming rate 50 of model projections Christy et
al. 2007, 2009
24Testing Hypotheses on Global WarmingTesting
Assertions based on Climate Models - Sierra
Nevada loses 80 of snow by 2100Observations
contradict this
25Sierras warm faster than Valley in model
simulations
Snyder et al. 2002
26Trend 1.1 cm/decade
Christy and Hnilo 2010 .
27Testing Hypotheses on Global Warming2. (b)
Testing Assertions based on Climate Models
concerning Tropical Upper Air Temperature
trendsClimate models tend to misrepresent the
observed relationship
28A Climate Model Simulation is a Hypothesis How
does one define a falsifiable test for a model
hypothesis?
29Douglass, Christy, Pearson and Singer
2007 Select a prominent metric dependent on the
main perturbation in forcing - a large signal -
test against observations One such signal is the
vertical structure of the tropical tropospheric
temperature trend - i.e. how surface and upper
air trends compare
30Vertical Temperature Change due to Greenhouse
Forcing in Models
Model Simulations of Tropical Troposphere
Warming About 2X surface Lee et al. 2007
31C/decade
Best Estimate of Models - given surface trend
close to observed
32C/decade
Upper air trends of four observed datasets are
significantly cooler in this apples to apples
comparison
33C/decade
Upper air trends of four observed datasets are
significantly cooler in this apples to apples
comparison (Douglass et al. 2007).
34C/decade
Putting the hot and cold extremes (thick red) of
model trends tied to actual surface trend, models
are still too hot which in this case all models
have been tied to the actual observed surface
trend.
35A different test asks whether the models and
observational upper air trends agree if NO
restriction is placed on the model surface trends
(i.e. apples to oranges.) Extremely weak
hypothesis to test and does NOT address the
sfc-to-upper air relationship (a key signature of
greenhouse warming in models.)
36C/decade
Putting the hot and cold extremes (thick red) of
model trends tied to actual surface trend, models
are still too hot which in this case all models
have been tied to the actual observed surface
trend.
37Ratio of Lower Tropospheric Trend to Surface
Trend (Amplification Ratio)
Model Median
Christy et al. 2007, 2010 Christy and Norris
2006, 2009 Randall and Herman 2008 Klotzbach et
al. 2009, 2010 McKitrick et al. 2010
38Observations (Surface much more than upper air)
Land Surface Temperatures overstate warming
Model Expectation (Surface less than upper air)
39Klotzbach et al. 2010
Table 2 displays the new per decade linear trend
calculations of difference between global
surface and troposphere using model amplification
factor over land and ocean. All trends are
significant at the 95 level.
Christy et al. 2010
Our result is inconsistent with model
projections which show that significant
amplification of the modeled surface trends
occurs in the modeled tropospheric trends.
McKitrick et al. 2010
Over the interval 1979-2009, model-projected
temperature trends are two to four times larger
than observed trends in both the lower and
mid-troposphere and the differences are
statistically significant at the 99 level.
Note recalculated Santer et al. 2008 method,
and even with surface trend variation found
Santer et al.s result is not verified.
40- Testing Hypothesis (assertions) about Climate
- UAHuntsville builds datasets from scratch
- Popular surface temperature datasets tend to be
poor metrics for checking on the greenhouse
effect - and they are often poorly measured as
well - Warming is occurring but at a rate and in a
manner that is inconsistent with model
projections of enhanced greenhouse warming - Sensitivity research suggests the climate system
is less sensitive to CO2 increases (as depicted
in models) due to unaccounted-for negative cloud
feedbacks - 4. Impacts on global emissions of current
legislative actions are minuscule and will have
no discernable impact on whatever the climate is
going to do
41Testing Hypotheses on Global Warming3. Testing
Assertions on the sensitivity of the climate to
increases in greenhouse gas forcingClimate
models tend to overstate the sensitivity due to
missing negative cloud feedbacks
42Response of Clouds and Water Vapor (shortwave and
longwave) to Increasing CO2
Negative Feedback? (mitigates CO2 impact)
Positive Feedback? (enhances CO2 impact - models)
43A Climate Model Simulation is a Hypothesis How
does one define a falsifiable test for a model
hypothesis?
44Select a prominent metric dependent on the main
perturbation in forcing - a large signal - test
against observations One such test is to
calculate the climate feedback parameter during
monthly and annual scale variations
45Spencer and Braswell
46Global Warming in Models isGreatly Magnified by
Positive Feedbacks
Warming in models amplified by clouds vapor (3
deg. C by 2100)
Warming from CO2 only
Satellite data suggests clouds reduce
warming (0.5C by 2100)
Spencer and Braswell .
47- Testing Hypothesis (assertions) about Climate
- UAHuntsville builds datasets from scratch
- 1. Popular surface temperature datasets tend to
be poor metrics for checking on the greenhouse
effect - and they are often poorly measured as
well - 2. Warming is occurring but at a rate and in a
manner that is inconsistent with model
projections of enhanced greenhouse warming - 3. Sensitivity research suggests the climate is
less sensitive to CO2 increases than depicted in
models due to unaccounted-for negative cloud
feedbacks - 4. Impacts on global emissions of current
legislative actions are minuscule and will have
no discernable impact on whatever the climate is
going to do
48Testing Hypotheses on Global Warming4. Testing
Assertions the impact of regulations on
climateRegulations will have a minuscule impact
on whatever the climate is going to do
49What did California do?
- Force a limit on emissions of Light Duty Vehicles
- California AB 1493 seeks to reduce tail-pipe
emissions of CO2 by 26 by 2016 - 11 NE States adopted AB 1493
- Trial in Federal Court (Burlington VT) to address
the engineering, legal and climate issues of AB
1493, April-May 2007
50What did California do?
- Force a limit on emissions of Light Duty Vehicles
- California AB 1493 seeks to reduce tail-pipe
emissions of CO2 by 26 by 2016 - 11 NE States adopted AB 1493
- Trial in Federal Court (Burlington VT) to address
the engineering, legal and climate issues of AB
1493, April-May 2007
51What did California do?
- Force a limit on emissions of Light Duty Vehicles
- California AB 1493 seeks to reduce tail-pipe
emissions of CO2 by 26 by 2016 - 11 NE States adopted AB 1493
- Trial in Federal Court (Burlington VT) to address
the engineering, legal and climate issues of AB
1493, April-May 2007
52What did California do?
- Force a limit on emissions of Light Duty Vehicles
- California AB 1493 seeks to reduce tail-pipe
emissions of CO2 by 26 by 2016 - 11 NE States adopted AB 1493
- Trial in Federal Court (Burlington VT) to address
the engineering, legal and climate issues of AB
1493, April-May 2007
53IPCC Best Estimate
54California AB 149326 CO2 reduction LDV 2016
55The temperature impact on global temperatures if
the entire world adopted AB 1493 is an
undetectable 0.03C. Latest sensitivity results
suggest the impact is even smaller.
56Judge William Sessions III Ruling 12 Sept
2007 AB 1493 is legal
Pg 46 Plaintiffs expert Dr. Christy estimated
that implementing the regulations across the
entire United States would reduce global
temperature by about 1/100th (.01) of a degree by
2100. Hansen did not contradict that testimony.
57Questions
- What could make a dent in forecasted global
temperatures? - What would be the impact of building 1000 nuclear
power plants and putting them on-line by 2020? - (average 1.4 gigawatt output each)
58Questions
- What could make a dent in forecasted global
temperatures? - What would be the impact of building 1000 nuclear
power plants and putting them on-line by 2020? - (average 1.4 gigawatt output each)
59IPCC Best Estimate
60Net Effect of 10 CO2 emission reduction to A1B
Scenario(1000 Nuclear Plants by 2020)
61- Testing Hypothesis (assertions) about Climate
- UAHuntsville builds datasets from scratch
- Popular surface temperature datasets tend to be
poor metrics for checking on the greenhouse
effect - and they are often poorly measured as
well - Warming is occurring but at a rate and in a
manner that is inconsistent with model
projections of enhanced greenhouse warming - Sensitivity research suggests the climate is less
sensitive to CO2 increases than depicted in
models due to unaccounted-for negative cloud
feedbacks - 4. Impacts on global emissions of current
legislative actions are minuscule and will have
no discernable impact on whatever the climate is
going to do
62Kenya, East Africa
63Energy System
Energy Source
Energy Transmission
Energy Use
64Consensus is not Science
Michael Crichton
65Consensus is not Science
Michael Crichton
All Science is numbers
William Thomson (Lord Kelvin)
66(No Transcript)