Clearing the Air
Examining the evidence
of climate change
You may have heard statements like…
• “Most climate scientists agree.”
• “Most scientists don’t agree.”
• “Since we can’t predict the weather next week,
we can’t know it will be warmer in 100 years.”
• “Carbon is natural – what’s the problem?”
• “Sea level has already risen and will continue in
this century.”
Beliefs and Science
• People believe many things to be true
– Beliefs are ideas for which we think are true
– They may be based on evidence, faith, or worldviews
• Assumptions are underlying ideas, principles
– Used to connect evidence to conclusions
– May or may not be reasonable
• Science is a process of understanding the natural world
– Helps us understand what is happening with evidence
– Assumptions are stated, tested, and reviewed
Language of Science
• Data: Observations and measurements, collected through
standard methods
• Evidence: Interpreted data that supports or challenges a
scientific idea.
• Theory: Well-established explanation for how or why a
phenomenon happens
– Strongly supported by many different lines of evidence
• Uncertainty: The range of values within which the true value
is likely to fall.
– All measurements have some degree of uncertainty
– Doesn’t mean “unsure”
Weather
• What we see or feel outside right now
• Daily changes of temperature, rainfall,
humidity, wind, and clouds.
• Ranges from a few days to a few weeks
• Example: today is sunny; the high temperature
yesterday was 78F
Weather Forecasting
• Weather models take into account:
– Atmospheric processes
– Land surface
– Nearby oceans
• Weather forecasting accuracy decreases over
a few days
• Tomorrow’s high temperature is weather
forecasting
Climate
• The long term averages and trends of weather
patterns over a given period of time at a
given location.
• Climate changes cannot be seen annually.
• Ranges from a few years, to centuries
• Example: Normal monthly precipitation (30 yr
average over 1971-2000) in April in Orlando is
2.7 inches
Climate Forecasting
• Need to account for slow changing conditions:
– Amount of snow
– Type of land cover
• Global climate models take into account:
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Atmospheric conditions and particulates
Land surface
Ocean and sea ice
Vegetation
Carbon cycling
• Seasonal precipitation for 2013 or future climate
in 2100 are examples of climate forecasting
Global Warming
• An average temperature increase of the Earth over time.
Hansen, James, Makiko Sato, Reto Ruedy, Ken Lo, David W. Lea, and Martin Medina-Elizade. "Global Temperature Change." Proceedings of the National Academy of Sciences
103.39 (2006): 14288-4293. Goddard Institute for Space Studies. National Aeronautics and Space Administration, 31 July 2006. Web. 2 July 2012.
Climate Change
• Includes a variety of likely changes
– The effects will not be the same everywhere
• Includes changes to:
– Temperature
– Precipitation
– Sea Ice
– Sea Level
– Extreme Weather Events
WHAT IS THE EVIDENCE OF CHANGE?
Temperature
Courtesy: The Weather Channel
Average Temperature 1961-1990
McKenny, Dan, Megan Embrey, Amy Lee, Anantha Aiyyer, Bridget Lassiter, Ryan Boyles, Ashley Frazier, Sharon Schulze, and Heather Dinon. "Climate and Weather." Climate
Education for Agriculture. NC State University, Web. 13 July 2012. <http://nc-climate.ncsu.edu/edu/ag/ClimateandWeather>.
Temperature
IPCC, 2007: Summary for Policymakers. In: Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the
Intergovernmental Panel on Climate Change [Solomon, S., D. Qin, M. Manning, Z. Chen, M. Marquis, K.B. Averyt, M.Tignor and H.L. Miller (eds.)]. Cambridge University Press,
Cambridge, United Kingdom and New York, NY, USA.
Precipitation
Arctic Sea Ice
1979
2009
Sea Ice
Armstrong, Richard L. "Sea Ice." State of the Cryosphere. National Snow and Ice Data Center, 21 May 2012. Web. 13 July 2012.
<http://nsidc.org/cryosphere/sotc/sea_ice.html>.
Sea Level
Hansen, James, and Makiko Sato. "Sea Level." Updating the Climate Science: What Path Is the Real World Following? Columbia University, 26 June 2012. Web. 13 July 2012.
<http://www.columbia.edu/~mhs119/SeaLevel/>.
Ecosystem
Bergengren, Jon C., Duane E. Waliser, and Yuk L. Yung. "Ecological Sensitivity: A Biospheric View of Climate Change." Climate Change 107.3 (2011): 433-57. SpringerLink. Web.
22 June 2012.
What does this all mean?
• Scientists combine this evidence to draw
conclusions:
– Earth’s climate is currently changing.
– Changes are not the same at all locations on Earth.
– Future changes may be more rapid than historical
changes.
• They look at evidence
– If these trends do not match historical averages or if
they appear to be accelerated, then climate is
changing differently than it has in the past.
WHY IS CLIMATE CHANGING?
Natural and Anthropogenic Changes
Climate is defined by several forces
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Solar radiation
Ocean composition
Greenhouse effect
Albedo effect
Continental land arrangement
There have been natural fluctuations in these
forces that have caused past climate change
– Are they causing current changes?
The next three slides are to come.
• There are some people who believe that the
climate change we are seeing today is due to
other natural forces, and not anthropogenic
– Changes in volcanic activity
– Changes in solar radiation
– Increased solar flares and sun spots
– Changes in Earth’s orbit around the sun
Solar Radiation
"Glacial-Interglacial Cycles." NOAA Paleoclimatology Program. USA.gov, 20 Aug. 2008. Web. 31 July 2012.
Volcanic Eruptions
"Frequently Asked Questions about the Science of Climate Change – 2008 Update." Environment Canada. N.p., 18 June 2012. Web. 31 July 2012.
<http://www.ec.gc.ca/scitech/default.asp?lang=En>.
Global and continental temperature change
But natural forces alone do not explain the changes we
have been seeing
We have also altered the atmosphere
• Carbon dioxide (CO2)
– Currently 396 ppm; 35% rise since Industrial
Revolution
• Methane (CH4)
– Currently 1800 ppb; from 700 ppb
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Nitrous oxide (N2O)
Chlorofluorocarbons (CFC’s)
Ozone (O3)
Water Vapor (H2O)
CO2
CH4
N2O
Human Forces
Humans have amplified the greenhouse effect by putting
more greenhouse gases in the atmosphere at an accelerated
rate
Focus on CO2
• People tend to focus on CO2 because it is the one we
have changed the most.
• CO2 is a greenhouse gas that scientists think has caused a
lot of the warming to take place
Carbon is Everywhere!
USING MODELS TO PROJECT THE
FUTURE
What Will Happen In the Future?
• Scientists also use models to project temperature changes
with different assumptions for emissions
"Temperature Projections." Consortium for Atlantic Regional Assessment. Global Change Research Program, US EPA, 23 Jan. 2006. Web. 13 July 2012.
<http://www.cara.psu.edu/climate/emissionscenarios3.asp>.
What Will Happen In the Future?
• Scientists also use models to project precipitation
changes
"Plots and Animantions." Climate Research Activities. Environment Canada, 19 Apr. 2010. Web. 13 July 2012. <http://www.cccma.ec.gc.ca/diagnostics/cgcm3t47/plot_pcp_glb.shtml>.
Ecosystem
Future
Current
Model
Modeled
– Low
HighEmissions
Emissions
Forest
Courtesy: US Forest Service Tree Atlas
And what could happen here?
• Florida’s climate is largely influenced by El Nino and La
Nina
• Sea level rise
– coastal erosion
– groundwater contamination
• Warmer temperatures
– more invasive exotic organisms
– greater risk of wildfire
– Increased yield in some crops if water is plentiful
• Less rain in the growing season
– harm crops, or change planting times
WHY DOESN’T EVERYONE AGREE?
It’s a Challenge
• The science and the system are very complex
– Most of us are not climate scientists
– Feedback loops and delay, not linear cause/effect
• Will not impact every region in the same way
• Can not exactly predict the future – too many
variables
• Not just a scientific issue
– International, Political, Moral, Economic issue
• Some changes are expensive
• Changes are hard to see
• My actions do not affect me
Climate Change is Difficult to See
• Changes take a while to detect because of
short-term variations
• Changes are often detected where people do
not live
• People spend less time in nature so changes
may be more difficult to see
• Delayed results mean people may not see how
their behavior impacts the climate
But why disagreement?
• People perceive and remember information
that matches their existing mental model
– So it is hard to change someone’s opinions
• People have partial information and leap to
conclusions
– And it is hard to provide complete information
• People listen to influential leaders
– rather than figuring it out for themselves
Skeptics and Deniers
• Skeptics question data,
interpretations, and
recommendations
• Skeptics are open to
various ideas – with
decent proof
• Skeptics are valuable –
they help to challenge
the data!
• Deniers repeat favored
statements without
questioning.
• No amount of
information will change
a denier’s mind
The U.S. Public Holds Different Beliefs
about Climate Change
Homework
• Use today’s information to evaluate
statements about climate change.
– Underline the sentences supported by scientific
data
– Circle the reasoning following the evidence.
– Star the final conclusion
• If you think that the conclusion is false, or not
supported well enough:
– Explain what information is lacking
– Rewrite the conclusion to make it more accurate
Example
The Earth’s orbit has been tracked and studied for hundreds of years though various
astronomical research.
The shape of the Earth’s orbit is elliptical, not circular. Because of this shape, the
Earth is farther from the Sun during part of the year than other times.
It is colder in the winter,
so the Earth must be farther from the Sun, receiving less solar energy, making it
cold.
Therefore, the reason we see differences between winter and summer is because
of Earth’s elliptical orbit and our distance from the Sun.
Questions?
WHAT ARE SOME SOLUTIONS?
How to approach a problem?
• Project future conditions
• Assess the risks involved with various
scenarios
– If the risks are acceptable – adapt to changes
• Find crops that grow in warmer, drier conditions
– If the risks are unacceptable – mitigate the change
• Many options at many scales: global, national, state,
community
• Mostly around reducing emissions of GHG
Solutions to Climate Change
• Lots of options; no “one” solution
• Policies and actions implemented by
– Governments: international, national, state, local
– Industry and business
– Individuals – all of us!
• One goal of these solutions is to limit the
emissions of greenhouse gases
– Limiting emissions will decrease CO2 and some of
the effects of climate change
Reduce Emissions by Improving
Efficiency
• Fuel efficiency of vehicles
• Building heating/cooling/lighting
– Residential and commercial
– Home appliances
• Better ways to produce energy from fossil
fuels
– Increase efficiency of energy generation
Reduce Emissions through
Conservation
• Improving transportation systems
– Bicycle, carpool, public transportation
• Reducing fossil-fuel intensive systems
– Buy local
– Eat less meat
– Use fewer fertilizers
• Conserving electricity
• Reducing, reusing, recycling
Use Carbon Neutral Energy Sources
• Renewable Energy
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Solar
Biomass
Wind
Geothermal
Hydropower
Hydrogen
• Nuclear
Remove Carbon from Atmosphere
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Decrease rates of deforestation
Increase rates of reforestation
Manage forests for carbon sequestration
Manage agricultural crops and soils for carbon
sequestration
• Use carbon capture
• Substitute wood
The Bigger Picture
• Implement carbon taxes
• International agreements – Kyoto Protocol
• Manage the global population
CASE STUDY EXAMPLES
Kansas City Power and Light
– Company is committed to sound environmental
practices that maintain and preserve the integrity
of the planet
– Pioneering efforts to reduce environmental impact
of electric generation
– Spearville Wind Generation Facility provides 100.5
megawatts of renewable energy
Canary Initiative
• Aspen, Colorado
• Created in 2005 to address climate challenge
• Goal to decrease local GHG emissions by 30%
by 2020 and 80% by 2050
McNeil Biomass Plant
• Burlington, Vermont
– Began operation in 1984
– 50 megawatts net electrical generation
– Burns 76 tons of wood per hour
– Uses 70% produced from low-quality trees and
logging waste
– 25% produced from residues (chips
and bark from local sawmills)
– 5% comes from clean recycled wood
The 10% Challenge
– Group of local, regional, and state-level
professionals dedicated to the reduction and
education of greenhouse gas emissions and
climate change
– Mission is to help reduce emissions in households
by at least 5% and a total reduction of 25% by
2012.