Global
Warming
MythBusters
Webinar on Science Fact & Science Fiction
Featuring Professor Brian Soden,
IPCC Author
Agenda
• General discussion of scientific credibility
• Common myths about climate change
• Questions & Answers
Sponsored by the Florida Business Network for a Clean Energy Economy
Dr. Brian Soden
• Professor of Meteorology and Physical Oceanography
• Rosenstiel School for Marine and Atmospheric
Science, University of Miami
• Lead Author for the Intergovernmental Panel on
Climate Change, WGI/AR4
• Climate change
Intergovernmental Panel on Climate Change
2007 IPCC Report
• Started 2004
• Completed February 2007
• 152 Authors
• ~450 contributors
• ~600 expert reviewers
• 30,000+ review comments
Contents
• Summary for Policymakers
• Technical Summary
• 11 Chapters
• Frequently Asked Questions
• ~5000 literature references
• ~1000 pages
The IPCC Sequence of Findings
IPCC (1990) “The unequivocal detection of the enhanced greenhouse effect
from observations is not likely for a decade or more.”
IPCC (1995) “The balance of evidence (>50%) suggests a discernible
human influence on global climate.”
IPCC (2001) “Most of the warming of the past 50 years is likely (>66%) to be
attributable to human activities.”
IPCC (2007)
Actual 1995-2000 observations
… one of the most important outcomes of your study
could be a clear statement of our present ignorance. That
in itself should indicate the need for contingency plans.
- Panel Respondent
The IPCC Sequence of Findings
IPCC (1990) “The unequivocal detection of the enhanced greenhouse effect
from observations is not likely for a decade or more.”
IPCC (1995) “The balance of evidence (>50%) suggests a discernible
human influence on global climate.”
IPCC (2001) “Most of the warming of the past 50 years is likely (>66%) to be
attributable to human activities.”
IPCC (2007) “Warming is unequivocal, and most of the warming of the past
50 years is very likely (>90%) due to increases in greenhouse gases.”
Myth #1
Its not warming
Skeptic Argument
There are problems with the data
record, “urban heat island” effects, the
data show no warming, the data are
fudged, etc.
Response
• Globally, the temperature has warmed
by ~1.5 F since 1880.
• Temperature records with urbanization
effects are removed.
• Largest warming is in remote regions –
Arctic, Canada, Siberia – not urban areas
• Consistent indications of warming in
other non-instrumental records.
• Evidence for warming is unequivocal.
The World Has
Warmed
• Globally averaged, the planet is
about 0.8°C (~1.5°F) warmer
than it was in 1880.
• Eleven of the last 12 years are
among the 12 warmest since 1880.
Consistent Patterns of Warming
• Mountain glaciers are retreating
• Arctic sea ice is decreasing
• Greenland is melting
• Snow/permafrost decreasing
• Sea level is rising
• Ocean heat content is increasing
• More intense droughts
• Atmospheric moisture increasing
• Heavier rainfall events
• Increased heat waves
WARMING IS UNEQUIVOCAL
Myth # 2
“But the globe is cooling!”
Skeptic Argument
Global warming stopped a decade ago.
The earth is actually cooling.
Response
• Climate change is recorded over long
periods of time (at least 30 years)
• Trends occur over a longer period of
time than just 10 years.
• The experts show no cooling trend and
in fact the opposite is actually occurring
(e.g., warming trend).
Climate Models Expect This
Observed and Predicted Changes in Global Temperature
Observations
Climate
Model
Predictions
We don’t expect each year to be warmer than the previous one.
Myth # 3
“It was freezing this winter. That proves global
warming is wrong”
Skeptic Argument
2010 was one of the coldest winters on
record for Florida and SE US.
Response
• Globally, 2010 was the 5th warmest
winter (DJF) on record.
• Big difference between climate and
weather.
• Natural fluctuations can cause local,
year-to-year variations in temperature.
• The signal of global warming emerges
from this background noise on larger
space and time scales: decade to decade
changes in global temperature.
Myth #4
OK, but mankind is not causing the warming
Skeptic Argument
Climate change is happening, but it is a
natural phenomenon. Mankind is not
impacting climate. The climate has
changed before man existed, so this
must be natural.
Response
• There are natural changes in climate,
e.g., ice ages, etc. But …
•The changes we are seeing now are
much more rapid than anything that
we’ve seen naturally.
• Natural causes of climate change (sun,
volcanoes, orbital changes, plate
tectonics) can’t explain the warming.
•The observed warming is consistent
with the measured increase in carbon
dioxide and other GHGs.
Temperature Change (oF)
Evidence for Human Caused Climate Change
The rate of warming over the
past century is unusual.
1250
1500
1750
2000
Carbon Emissions
CO2 Concentration (ppb)
1000
The rapid warming coincides
with increasing carbon dioxide.
1000
1250
1500
1750
2000
Carbon Emissions from Human Activity
1000
1250
1500
1750
The increasing carbon dioxide
is due to human activities,
primarily burning fossil fuels.
2000
Myth # 5:
You forgot about the sun
Skeptic Argument
If the earth is warming, then it is
because of increases in solar output.
Solar radiation is probably one of the
most important determinants of global
warming.
When there is more output, our climate
warms. Less output, our climate cools.
Response
• We can measure solar radiation output
and how it changes temperature.
• In the last 50 years of global warming,
the sun has shown a slight cooling
trend.
• The current rise in temperatures
cannot be explained by changes in solar
output alone.
• Most warming is occurring at night,
not daytime.
• Stratosphere is cooling while surface
warms. This is inconsistent with a
solar/volcano explanation.
What About the Sun?
Changes in solar activity contributed to the warming in the first half of the
20th Century, but can NOT explain the warming observed since the1950s.
Comparison of Modeled and Observed Temperature
Myth # 6:
It’s a Natural Cycle, like El Nino and La Nina?
Skeptic Argument
Mankind is not responsible for global
warming. These are just natural cycles
like El Nino. They happen all the time.
There is nothing we can do about it
Response
• El Nino and La Nina happen on very
short time scales (2-3 years). They can
not explain long term warming trends.
• Other unidentified “natural cycles” are
just speculation, not science.
Myth # 7
“There is no scientific consensus.”
Skeptic Argument
I read a petition that showed thousands
of scientists in opposition to global
warming.
Response
• Over 97% of experts* (scientists who
actively engage in research on climate
change) believe that the climate has
warmed and that humans are
responsible for most of the warming
over the past 50 years.
• Petitions claiming otherwise are bogus.
• If you’re still a big fan of petitions and
conspiracy theories, you should like
www.911truth.org
* 2009 survey by Univ. of Illinois
Scientific Consensus
The National Academy of Sciences:
“The scientific understanding of climate change is
now sufficiently clear…(we urge) prompt action to
reduce the causes of climate change.” 2005
Intergovernmental Panel on Climate Change:
“Most of the observed increase in globally averaged
temperatures since the mid-20th century is very likely due to
the observed increase in anthropogenic greenhouse gas
concentrations.” 2007
American Association for the Advancement of Science
Society for Industrial and Applied Mathematics
Ecological Society of America
Botanical Society of America
American Society of Plant Biologists
American Meteorological Society
American Geophysical Union
American Geophysical Union
American Statistical Association
American Chemical Society
Myth # 8
“Climate Gate proved there’s a conspiracy.”
Skeptic Argument
Response
I heard about the ClimateGate scandal
on Fox News. Climatologists are
manipulating the truth by hiding crucial
data.
•The vast majority of data is available to
the public and results are reproduced by
multiple institutions and scientists. See
www.giss.nasa.gov
There is a conspiracy that squashes any
scientists that isn’t on board.
• Analyses are repeated and conclusions
verified.
• Two separate UK Parliamentary
committees have investigated Climate
Gate and exonerated Dr. Phil Jones of
any scientific misconduct.
Climategate 101:
Jones e-mail of 16 Nov 1999
"I've just completed Mike's Nature trick of adding in the real temps to each
series for the last 20 years (ie, from 1981 onwards) and from 1961 for
Keith's to hide the decline."
Myth # 10
“Climate scientists are in it for the money.”
Skeptic Argument
Response
These scientist have a vested interest in
making it seem like their research is
important.
• Scientists are paid to investigate things
that are uncertain, not certain.
Global warming alarmists and are just
doing this to keep the grant dollars
flowing.
• By emphasizing certainty in their
predictions, scientists are undermining
their argument for research funds.
Follow the Money
www.ExxonSecrets.org
Fossil Fuel Funding
Since 1998, ExxonMobil has put
$22,123,456 toward climate science denial.
• Pat Michaels - Dr. Michaels has acknowledged that 20% of his funding
comes from fossil fuel sources.
• The Heartland Institute - $830,000 from Exxon
• The CATO Institute - $125,000 from Exxon
• American Enterprise Institute - $1,860,000 from Exxon
• George C. Marshall Institute - $745,000 from Exxon
• Heritage Foundation - $565,000 from Exxon
These financial figures represent Exxon funding from 1998 until 2006.
www.ExxonSecrets.org
Questions?
Resources
• Florida Energy Systems Consortium www.floridaenergy.ufl.edu
• Union of Concerned Scientists www.ucsusa.org
• NASA’s climate change web site
http://climate.nasa.gov/warmingworld/
• Climate Ethics http://climateethics.org/
• Real Climate www.realclimate.org/
• Clean Energy Works www.cleanenergyworks.us/
• American Business For Clean Energy
www.AmericanBusinessForCleanEnergy.org
• Clean Energy Stories www.cleanenergystories.org/
Reliability of Proxy Temperature Records