Climate Change
What Does the Science Really Tell Us?
Craig Cogger
WSU Puyallup
NASA Johnson Space Center
http://www.puyallup.wsu.edu/soilmgmt/ClimateChange.htm
Climate Change
•Greenhouse effect
•Important Definitions
•Climate science pioneers
•Historical climate change
•Evidence for current climate change
•Climate models
•What does climate change mean for people and the environment
•Contrary views
•The take-home message
•Introduction to climate policy
NASA Johnson Space Center
Simplified
Effect
Simplified Greenhouse
Greenhouse Effect
Energy radiates from the earth
back toward space as lower-energy
radiates
back toward space
infrared waves
Energy
as lower-energy infrared waves
2
Solar energy
passes
through
atmosphere 1
and is
absorbed by
the earth
Some of the
energy is
reflected by
ice, snow,
and clouds
3
Greenhouse gases absorb
and re-radiate some of the
infrared energy, trapping
heat in the atmosphere.
Greenhouse gases absorb
and re-radiate some of the
infrared energy, trapping heat
in the atmosphere.
Solar energy passes
through atmosphere and
is absorbed by the earth
Artwork by Andrew Mack, WSU
Greenhouse gases include carbon
dioxide, water vapor, nitrous oxide,
methane, and ozone.
Carbon Dioxide
Water
Absorb infrared energy and
act like a blanket
Without the greenhouse
effect, earth’s mean
temperature would be 0o F,
nearly 60o lower than it is
now
Images: Globalwarmingart.com/Ben Mills
The Problem:
We are increasing atmospheric CO2, adding to
the greenhouse effect, and warming the planet.
Tans and
Keeling, 2012
The greenhouse effect is part of a
complex climate system.
NASA Earth Observatory
NCAR
DLESI
Atmospheric Circulation moves heat
Carbon Cycle moves, transforms, and stores CO2
Rahul Zaveri USDOE PNNL
Greg Holloway, Institute
of Ocean Sciences,
Sidney, BC
Ocean Circulation moves and stores heat and CO2
Aerosols interact with solar energy
QUIZ TIME!
Artwork by Andrew Mack, WSU
Part 2
A Few Important Definitions
(Often Misunderstood)
Katey Walter Anthony, U Alaska-Fairbanks
Mary Cogger
J.C. Willett U.S. Geological Survey
What is the difference between
weather and climate?
Weather: The current state of the
atmosphere (hours, days, weeks, months)
Climate: Average weather over time (30
years or more)
Climate is what you
expect, weather is
what you get
San Antonio Daily
Mary Cogger
Weather:
http://www.ncdc.noaa.gov/sotc/global/2012/8
Climate:
http://data.giss.nasa.gov/gistemp/2011/Fig2.gif
Climate forcing affects global energy
balance, forcing a change in climate.
Coal-fired power
plant emitting CO2
NOAA
SOHO (ESA & NASA)
J.C. Willett U.S. Geological Survey
Credit: NOAA
USGS
Climate feedback amplifies or
dampens climate forcing.
Photo by Gifford Miller, Univ. Colorado
NASA Johnson Space
Center
Katey Walter Anthony, U Alaska-Fairbanks
NOAA
NASACredit:
Visible
Mary
CoggerEarth
NASA
A warmer atmosphere holds more
water vapor, absorbing more energy –
a positive feedback.
NASA Johnson Space Center
Snow and ice melting are a
positive feedback.
Photo by Gifford Miller, Univ. Colorado
UNEP
More melting
less reflection of heat
more warming
Thawing permafrost and soil release
greenhouse gases, another positive feedback
Katey Walter Anthony, U Alaska-Fairbanks
Changes in cloud cover have both
positive and negative feedbacks.
National Oceanic and Atmospheric Administration/Department of Commerce
Mary
JonCogger
Sullivan
2-Minute Drill
What is the difference between weather
and climate?
What is climate forcing? What is an
example of climate forcing?
What is climate feedback? What is an
example of climate feedback?
Part 3
Climate Science Pioneers
AIP Emilio Segre Visual Archives
Scientists first demonstrated the
cause of the greenhouse effect
more than a century ago.
John Tyndall, 1859
 Discovered that CO2 and H2O
absorbed infrared radiation,
causing “greenhouse effect”
Scientists first demonstrated the
cause of the greenhouse effect
more than a century ago.
John Tyndall, 1859
 Discovered that CO2 and H2O
absorbed infrared radiation,
causing “greenhouse effect”
Svante Arrhenius, 1896
 First calculations estimating
effect of changes in atmospheric
CO2 on global temperatures
Scientists first demonstrated the
cause of the greenhouse effect
more than a century ago.
John Tyndall, 1859
 Discovered that CO2 and H2O
absorbed infrared radiation,
causing “greenhouse effect”
Svante Arrhenius, 1896
 First calculations estimating
effect of changes in atmospheric
CO2 on global temperatures
Mid 20th century scientists improved our
understanding of the greenhouse effect.
With kind permission, G.S. Callendar
Archive, University of East Anglia.
Guy Callendar, 1938
 Linked rising temperatures of early
20th century with fossil fuel CO2
emissions
Mid 20th century scientists improved our
understanding of the greenhouse effect.
Gilbert Plass, 1950s
Detailed calculations from spectroscopic
data confirmed that increasing CO2
concentrations would trap more heat in the
atmosphere.
With kind permission, G.S. Callendar
Archive, University of East Anglia.
Guy Callendar, 1938
 Linked rising temperatures of early
20th century with fossil fuel CO2
emissions
Hodges Photographers, courtesy
AIP Emilio Segre Visual Archives
By the 1960s scientists had demonstrated
increasing levels of CO2 in the atmosphere.
AIP Emilio Segre Visual Archives
Roger Revelle and Hans
Suess, 1950s
 Demonstrated that more CO2
was going into atmosphere than
previously assumed
By the 1960s scientists had demonstrated
increasing levels of CO2 in the atmosphere.
Charles David Keeling, 1950s-60s
 Meticulous measurements of
atmospheric CO2 increase at Mauna
Loa
AIP Emilio Segre Visual Archives
Roger Revelle and Hans
Suess, 1950s
 Demonstrated that more CO2
was going into atmosphere than
previously assumed
Part 4
Probing the Historical Climate Record
Using Climate Proxies:
A trip in the Wayback Machine
US Geological Survey, Don Hickey
Scientists use many types of proxies
to understand historical climate.
Lake Sediments
Tree Rings
Coral Cores
US Geological Survey, Don Hickey
Elizabeth Thomas, Brown Univ.
Laboratory of Tree Ring Research
Univ. of Arizona
Northern hemisphere climate proxy data shows
that current temperatures are likely the
warmest in the last millenium.
Mann et al., 2008. doi: 10.1073/pnas.0805721105
Antarctic ice core data
demonstrate the link between
atmospheric CO2 and temperature.
Sepp Kipfstuhl, AWI
Produced by Leland McInnes from EPICA data
Since temperature change preceded
CO2 change, is this evidence against
the greenhouse effect?
?
Produced by Leland McInnes from EPICA data
?
Since temperature change preceded
CO2 change, is this evidence against
the greenhouse effect?
?
NO
Produced by Leland McInnes from EPICA data
Part 5
What is the Evidence for
Current Climate Change?
?
NASA and other datasets show
increasing global temperatures.
http://http://data.giss.nasa.gov/gistemp/2011/Fig2.gif
Temperature changes averaged by decade
clearly show the increasing trend.
2009 State of the Climate Highlights
Record high temperatures have begun to
exceed record lows in the United States.
©UCAR, graphic by Mike Shibao
Decline of arctic sea ice is another
indicator of a warming planet.
NASA Earth Observatory
Sept 14, 1984
Sept 13, 2012
Most of the world’s glaciers are losing
mass.
USGS Fact
Sheet
2009-3046
Observed ecosystem changes are
consistent with a warming planet.
Whitney Cranshaw, Colorado State University, Bugwood.org
Credit NOAA
Coral bleaching
US Forest Service
Severe mountain pine beetle
infestations
Melting glaciers and thermal expansion
of seawater cause sea level rise.
Leuliette, E. W, R. S.
Nerem, and G. T.
Mitchum, 2004: Marine
Geod., 27:79-94.
http://www.skepticalscience.com/graphics.php
Part 6
Climate Models:
Projections for the Coming
Decades
Are the models a useful tool?
(smoothed
curves)
IPCC 4th Assessment
IPCC 2007 Working Group 1 Summary for Policy makers Fig. SPM4. See notes for figure legend
Climate models project greater
temperature increases in this century.
IPCC 2007 Working Group 1 Summary for Policy makers Fig. SPM5. See notes for figure legend
IPCC model simulations project the greatest
warming over land and in the arctic.
IPCC 2007 Working Group 1 Summary for Policy makers Fig. SPM6. See notes for figure legend
IPCC precipitation projections for 20902099 show high latitudes becoming wetter
and some subtropical areas drier.
1980-1999 baseline
IPCC 2007 Working Group 1 Summary for Policy makers Fig. SPM7. See notes for figure legend
The latest projections of sea level rise
are in the range of 1 meter by 2100.
Saiful Huq Omi/Polaris, for The New York Times
Weiss et al., 2011
Part 7
What to Expect from Climate
Change
NASA Earth Observatory
Climate change is expected to increase
the probability of extreme weather
events (heat, drought, storms).
NASA Earth Observatory
“Climate trains the boxer, but weather throws the punches”
Deke Arndt, National Climatic Data Center
Dan Steinberg, AP
Climate change is expected to put
many species, ecosystems, and
human communities at risk.
Environment
 Species and ecosystem loss
 Greater wildfire risk
Human health and welfare
 60,000,000 refugees possible
from 1 m of sea level rise
 Increased range of tropical
diseases
 Conflicts over water, food, and
refugees
Dan Steinberg, AP
Photo by Chris Figenshau, BLM Alaska Fire Service
Increased risk to agriculture is
expected in many areas.
 More severe droughts
 Storms and flooding
 Loss of irrigation sources
 Increased pest problems
Brian Kersey, AP
Increased CO2 and longer growing season may benefit
crops for a number of decades in some temperate areas if
drought or pests do not limit production
Who will be affected most by climate
change?
Most of the human
greenhouse gases have
come from developed
countries.
The most vulnerable will be
those in developing
countries who have fewer
resources for adaptation.
Who is our neighbor?
Credit: pfly/flickr
Jenny Elizalde
Mary Cogger
Part 8
Isn’t There Another Point of View?
?
Volcanoes emit more
CO2 than humans
Part 8
Isn’t There Another Point of View?
Volcanoes emit more
CO2 than humans
One example:
Some claim that the sun is responsible for recent
climate change, but the data shows otherwise.
http://www.skepticalscience.com/graphics/Solar_vs_temp_1024.jpg
Part 9
Take-Home Message
Greenhouse effect
Take-Home Message
 The science is clear: Added
greenhouse gases warm the
earth
 Multiple lines of evidence
show effects of warming
across the globe
 We need to act now to avoid
the most severe harm to
people and the environment.
Recommended Reading
Cover Photo Copyright Peter Essick 2004
Readable, robust science, 2009
CLIMATE CHANGE 2007
SYNTHESIS REPORT
IPCC synthesis of the best science, 2007
(already a little out-of-date)
Well written by a
physicist/historian, 2008
Recommended Reading
Cover Photo Copyright Peter Essick 2004
Blogs with sound science
Readable, robust science, 2009
CLIMATE CHANGE 2007
SYNTHESIS REPORT
IPCC synthesis of the best science, 2007
(already a little out-of-date)
Well written by a
physicist/historian, 2008
Where do we go from here?
Many of the youngest among us will still be alive in
the closing decades of this century. How can we
shape the world they will be living in?
IPCC 2007 Working Group 1 Summary for Policy makers Fig. SPM5.
See notes for figure legend
Part 10
Responding to Climate
Disruption
We basically have three choices:
mitigation, adaptation and suffering.
We’re going to do some of
each. The question is
what the mix is going
to be? The more mitigation
we do, the less adaptation
will be required and the less
suffering there will be.
-John Holdren
Credit:NOAA
What do mitigation and adaptation
mean?
Mitigation
Reducing carbon emissions
Increasing carbon sequestration
Courtesy of DOE/NREL
Adaptation
Planning for the consequences:
Rising sea levels, changing rainfall
patterns, risk of more frequent severe
storms and wildfires, climate refugees,
threats to food production, etc.
The greatest mitigation challenge is
reducing fossil fuel use.
Fossil fuel provides 86% of world’s energy
Deforestation is #2 human source of CO2
Target 80% reduction in CO2 emissions by
2050 to avoid worst outcomes of
climate change
NASA Visible Earth
The “Wedge” analogy is a strategy to reach
greenhouse gas mitigation goals.
Example of mitigation “wedges”
Chris Benedict, WSU
Reprinted with permission of NRDC,
the Natural Resources Defense Council
NRDC
NRDC wedges concept based on:
S. Pacala and R. Socolow. 2004. Science 305:968-972
All photos courtesy DOE/NREL except as noted
Mitigation requires individual and government
action on a local and global scale.
Courtesy of DOE/NREL
We can begin at home with simple
conservation steps that save money and
reduce emissions.
Courtesy of DOE/NREL
Courtesy of DOE/NREL
Investment in energy conservation can
further reduce emissions and costs.
Typical Household Energy Use
in the USA
Other
Electronics
Heating
Photos Courtesy of DOE/NREL
Lighting
Cooling
Appliances
Hot water
USEPA Energy Star Program
Government action is vital.
Do we have the political will to do what is
needed to address global climate change?
Are we willing to put a price on carbon now?
Mary Cogger
Government policies can stimulate a
clean energy economy.
Carbon Tax
Cap and Trade
Renewable Energy
Mandates
Smart Grid
Research and
Development
Conservation
Clean
electrons
Energy
efficiency
Based on: Thomas Friedman, “Hot, Flat, and Crowded”, Pg. 195
The carbon tax is a transparent way
to reduce emissions by making fossil
fuels more expensive.
Reduced taxes on low
and middle income
households help
balance carbon tax
Successful in
Denmark, adopted in
British Columbia
Cap and trade encourages the
market to reduce emissions.
Sets limit (cap) on emissions
Allocate permits to release
emissions
Companies can trade permits
Cap on emissions shrinks
over time
Success story: Cap and trade
reduced sulfur emissions
Union of Concerned Scientists
Renewable energy mandates
decrease market uncertainty, spurring
innovation and investment
Courtesy of DOE/NREL
Courtesy of DOE/NREL
Some states have enacted renewable energy mandates for electric utilities.
The smart grid is a two-way connection
between consumers and utilities that
increases efficiency throughout system.
Courtesy of Electric Power Research Institute
Getting Involved
 Save energy at home and
work
 Learn more about climate
science
 Talk to your friends and
neighbors
 Write to decision makers
 Support organizations
who work for those in
greatest need
Cover Photo
Copyright Peter Essick 2004
http://www.puyallup.wsu.edu/soilmgmt/ClimateChange.htm