Global Warming: Global Warming: Manmade Mess or Natures Norm? or - - PowerPoint PPT Presentation

Global Warming: Global Warming:

Manmade Mess

• r Nature’s Norm?
• r Nature s Norm?
• Dr. Roy W. Spencer

Principal Research Scientist The University of Alabama in Huntsville

1) Only 29 of every 100,000 molecules of air are CO2

CO2 Is Necessary for Life on Earth

) O y 9 o e e y 00,000

• ecu es o a

a e CO 2) Mankind’s CO2 emissions are only ~ 5% of Natural Flows of CO2 3) NATURE CONSUMES ~50% OF OUR YEARLY CO2 EMISSIONS

The Greenhouse Effect of CO2 is SMALL The Greenhouse Effect of CO2 is SMALL

1 Water Vapor 1.Water Vapor

• 2. Clouds
• 3. Carbon dioxide

90-95%

• 4. Methane…

The Greenhouse Effect is a “radiative blanket”: The Greenhouse Effect is a radiative blanket : it traps heat in the lower atmosphere

Examples: Humid night warmer than dry, p g y, Cloudy night warmer than clear.

The DIRECT Warming effect of More CO2 from burning Fossil Fuels is small g

Projected INDIRECT effects are called “FEEDBACKS” Warming (deg. F) 6o 10o 4o 6o 6o – 10o 2o 4 – 6 <1o 2000 2020 2040 2060 2080 2100 YEAR

⇒All Climate Models Have Positive Feedbacks

Increasing CO2 causes weak warming at first, Warming is then AMPLIFIED by clouds, vapor

But What Evidence Supports P iti F db k i Cli t M d l ? Positive Feedback in Climate Models?

…but there’s just one problem….

• Mr. Gore ASSUMES that the CO2 changes

caused the temperature changes

Observed Behavior of the Ancient Climate System

Al Gore’s Stage Prop: The Vostok Ice Core Data

p g

Ice Core Data “Suggests” Positive Feedback….but….

…temperature LEADS CO2 by ~ 800 years in Ice Cores… (so Ice Core data are largely irrelevant to global warming) ( g y g g)

What if something else has caused warming? (science should always look for alternative hypotheses) alternative hypotheses)

We Use SATELLITES to figure out how TODAY’s Climate System works, and compare it to climate models climate models.

Observed Behavior of Today’s Climate System:

Satellite Comparisons of Clouds vs. Temperatures

NASA’s Aqua Satellite

There are TWO WAYS to Cause Global Warming 1) INCREASE solar radiation being absorbed, or 2) DECREASE i f d di ti b i l t t 2) DECREASE infrared radiation being lost to space.

1st SATELLITE TEST OF THE CLIMATE MODELS (how they gain and lose INFRARED energy)

1400 1000 1200 Periods

Positive Feedback (clouds AMPLIFY warming) Negative

600 800

• f 5-Year

18 IPCC Models

Feedback (clouds REDUCE warming)

GOOD AGREEMENT for EMITTED

200 400 Number o

S t llit

INFRARED

200

• 4
• 3
• 2
• 1

1 2 3 4 5 6 7

Satellite

4 3 2 1 1 2 3 4 5 6 7 Feedback Parameter Estimate (W m-2 K-1)

2nd SATELLITE TEST OF THE CLIMATE MODELS (how they gain and lose SOLAR energy)

1400

Negative Feedback (clouds REDUCE warming) Positive Feedback (clouds AMPLIFY warming)

1000 1200 Periods

warming) warming)

TERRIBLE AGREEMENT for REFLECTED

600 800

• f 5-Year

Satellite

SUNLIGHT

200 400 Number o

18 IPCC Models

200

• 4
• 3
• 2
• 1

1 2 3 4 5 6 7 4 3 2 1 1 2 3 4 5 6 7 Feedback Parameter Estimate (W m-2 K-1)

TOTAL SATELLITE TEST OF THE CLIMATE MODELS (how they gain and lose SOLAR+INFRARED energy)

1400

TERRIBLE AGREEMENT

1000 1200 Periods

Positive Feedback (clouds AMPLIFY warming) Negative

AGREEMENT for REFLECTED SUNLIGHT+ EMITTED

600 800

• f 5-Year

18 IPCC Models

Feedback (clouds REDUCE warming)

EMITTED INFRARED

200 400 Number o

Satellite

200

• 4
• 3
• 2
• 1

1 2 3 4 5 6 7 4 3 2 1 1 2 3 4 5 6 7 Feedback Parameter Estimate (W m-2 K-1)

Why Would Models Cause Clouds to AMPLIFY Warming?

(positive feedback => high sensitivity) (positive feedback => high sensitivity)

Again (as in CO2 temperature relationship): Cause versus Effect Cause versus Effect When researches examine satellite data, When researches examine satellite data, they assume temperature changes cause cloud changes (but not vice versa) …and so climate models are built f lt ti upon faulty assumptions.

IPCC Claim: Climate “Skeptics” Do Not Publish Their Results

(we publish but don’t publish anything (we publish, but don t publish anything the mainstream media likes)

• New Finding: Satellite observed tropical climate variability exhibits low

sensitivity: – Spencer, Braswell, Christy, & Hnilo, 2007: Cloud and Radiation Budget Changes Associated with Tropical Intraseasonal Oscillations Geophysical Research Letters August 9 Oscillations, Geophysical Research Letters, August 9.

• New Finding: A simple climate model used to demonstrate natural cloud

variability biases climate sensitivity estimates to the high side: S & B ll 2008 P t ti l Bi i F db k Di i – Spencer & Braswell, 2008: Potential Biases in Feedback Diagnosis from Observational Data: A Simple Model Demonstration, J. Climate (in press). – Reviewed by 2 IPCC model experts – Reviewed by 2 IPCC model experts.

• New Finding: Satellite observed global oceans shows low sensitivity,
• utside the range of ALL 18 IPCC climate models:

– Spencer & Braswell, 2008: Satellites Reveal a Climate System Less Sensitive than in Models, Geophysical Research Letters, submitt..

IF Manmade CO2 hasn’t Caused Global Warming

• ver the last 100 years..then what has?

HOW ABOUT MOTHER NATURE?

Pacific Decadal Oscillation, 1902-2006

0.8 1.2 1.6 2

c.

HOW ABOUT MOTHER NATURE?

Natural Cloud

1 2

• 0.8
• 0.4

0.4 PDO Index

Pacific Decadal Oscillation Cloud Variations

• 2
• 1.6
• 1.2

1902 1912 1922 1932 1942 1952 1962 1972 1982 1992 2002 YEAR 0 6

?

YEAR

Global

Global Mean Temperature, 1902-2006

0.2 0.4 0.6 (deg. C)

a.

LAND + OCEAN

Surface Temperature

• 0.4
• 0.2

T Anomaly OCEAN ONLY

Natural Temperature Variations

• 0.6

1902 1912 1922 1932 1942 1952 1962 1972 1982 1992 2002

A Simple Model Forced by Cloud Changes Assumed Associated with the Pacific Decadal Oscillation: Pacific Decadal Oscillation:

PDO Can explain 2/3 of 20th Century Warming

0.4 0.6

Simple Model of PDO Cloud Changes Causing Global Warming

Thermometer data

0.2 (deg. C)

PDO+CO2

• 0 4
• 0.2

T Anomaly

PDO-only

• 0.6
• 0.4
• 0.8

1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 YEAR

PDO INDEX

…and Recent Satellite Data Suggests that there Indeed IS a Connection between the PDO and Cloud Variations

1.5 2.0 2.5 2000 2001 2002 2003 2004 2005

PDO INDEX (monthly)

• 0.5

0.0 0.5 1.0 PDO Index

PDO Index 2000-2005

YEAR

CERES LW+SW Flux Anomalies

• 2.0
• 1.5
• 1.0
• 1.0
• 0.5

YEAR m-2 K-1)

60N-60S Oceans

Aqua Satellite

0.0 0.5 A Flux Anom. (W m

Observed Cloud Changes 2000 2005

1.0 1.5 2000 2001 2002 2003 2004 2005 TO

2000-2005

..so…Maybe Mother Nature Caused Climate Variability

• ver the Last 2,000 Years

0 8 1

2000 Years of Global Temperatures

(30-year averages, last data year 2007)

0 4 0.6 0.8

UK Met Office & U. of E. Anglia (thermometers

Medieval Warm Period 0.2 0.4 rees C

(thermometers, data years 1850-2007)

• 0.4
• 0.2

Deg

• Dr. Craig Loehle (2007)

Vikings arrive in Greenland End of Viking

• 0.8
• 0.6
• Dr. Craig Loehle (2007)

(average of 18 non-tree ring proxies, data years AD 1 - 1995)

Little Ice Age

End of Viking colonization of Greenland g Colonization of Greenland

• 1

100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000

YEAR (A.D.)

• R. W. Spencer, 2007

CO2 from Law Dome Ice Core

Science Conclusions

• 1. Satellite data + simple model suggest the

climate system is driven more by natural cloud changes than by CO2.

• 2. IPCC “Scientific Consensus” of CO2 driving climate is

g due to a mix-up between CAUSE and EFFECT when

• bserving natural cloud fluctuations.
• 3. If clouds drive climate change more than CO2, then

CO2 increases are not very important.

…but if there is any risk…

shouldn’t humanity avoid producing CO2?

• 1. Maybe not....

⇒No large-scale replacements for fossil fuels ⇒More CO2 increases agricultural productivity ⇒A little warming is, on whole, beneficial.

• 2. Why have most countries signed the Kyoto Protocol?

⇒Political power (follow the $$$) ⇒Transfer of wealth to poor countries ⇒Transfer of wealth to poor countries

• 3. Eventually, we’ll need replacements for fossil fuels

⇒This will require wealth for R&D ⇒ Wealth generation requires free markets…not gov’t regulation. g g

0.8 0.9 1 1.1

• deg. C.)

UAH Globally Averaged Satellite-Based Temperature

• f the Lower Atmosphere*

(Jan. 1979 - September 2008)

0 4 0.5 0.6 0.7 0.8

• Avg. Temp. (d

El Nino Warming

0.1 0.2 0.3 0.4

1979-1998 A

0 4

• 0.3
• 0.2
• 0.1

parture from

September 2008

• 0.6
• 0.5
• 0.4

1979 81 83 85 87 89 91 93 95 97 99 2001 03 05 07 09

YEAR Dep

• Mt. Pinatubo

Cooling

* Surface to 8 miles altitude

YEAR