What is the scientific consensus on
climate change and impacts?
University of Washington
Program on Climate Change
Who we are…
Graduate Students, University of Washington
Program on Climate Change
• Lia Slemons
• Robert Hahn
"I know of no safe repository of the ultimate
power of society but the
people. And if we think them not enlightened
enough, the remedy is not to
take power from them, but to inform them by
education."
- Thomas Jefferson
3rd President of U.S.
Author of the Declaration of Independence
Outline
• What are greenhouse
gases?
• How do they affect
climate?
• What will the future
look like?
• air
• water
• storms and drought
• What can we do?
Greenhouse
effect
GHG
GHG
GHG
• Sunlight heats the
earth
• To maintain an
equilibrium, Earth
reradiates the
energy to space
• Greenhouse gases
absorb this energy
• GHGs reradiate
some escaping
energy back
towards the surface,
making the
temperature warmer
Source: Murray ca. 2005
Human sources of
Greenhouse Gases
• ~50% of CO2
emissions to
atmosphere are
currently from humans
• Fossil fuel burning
represents 81% of
human sources of
GHGs
Source: Earth Trends 2008
Total CO2 emissions
U.S.
186.1
since 1950 in billions of tons
Time, 2001
European
Union
127.8
Russia
68.4
Ukraine
21.7
China
Poland
Canada
14.4
Kazakhstan
14.9
10.1
57.6
Japan
31.2
India
15.5
Mexico
7.8
Kuwait
Trinidad and
Tobago
Australia
South Africa
8.5
United
Arab
Emirat
es
7.6
Global Energy trends
Earth Trends 2008
• U.S. has ~4% of global population, and contributes ~25% of global
CO2 emissions.
• China now emits more CO2 than the U.S. (International Energy Agency, 2007)
• After 2010, China is predicted to surpass the U.S. to become the
world’s largest consumer of energy.
CO2 (ppm)
CO2 1958 to present
Year
• CO2 concentrations have increased since 1958
• Estimated increase of about 30% since 1850
(280 ppm to 370 ppm)
Δ Temperature ( F )
Δ Temperature ( C )
Instrumental Temperature Record
Source: NOAA
More Evidence: Ice Cores
• Ice layers preserve information about each year
Sources: NOAA, GISP2 websites
2050
2100??
Ice Core Evidence
CO2 and temperature, 420,000 BP to present
Today
4
2
340
0
300
-2
-4
260
-6
220
-8
180
Temperature differential, ºC
CO2 concentration, ppmv
380
-10
0
50,000
100,000
150,000
200,000
250,000
300,000
350,000
400,000
Years BP
Temperature differential
CO2 concentration
Source: various, (1) Vostok assembled by Davies 2000, (2) GISP2
Using Computer Models to Understand Climate
Natural Climate Influence
Human Climate Influence
All Climate Influences
Impacts of Climate Change
Regional focus on China
Typhoon Saomai (Aug. ‘06)
• Most powerful storm ever to
strike mainland China.
Landfall was in Zhejiang
Province
• 458 deaths--most were
caused by storm surge
flooding in coastal fishing
communities.
• $2.5 billion (2006 USD) in
damage -- 4.9 billion yuan in
Zhejiang alone.
• Six reservoirs in Jiangxi
Province were destroyed.
Temperature & Precipitation Patterns
“Will the wet will get wetter and the dry will get drier?”
--Dr. Isaac Held
Source: IPCC ARW4, Session 1, Figure 10.9
Source: GFDL Modeling Research Highlights
What Causes the Precipitation Changes?
Poleward Expansion of the Hadley Cells associated with
weakened equator-to-pole temperature gradients.
Source: Eastern Illinois University
Regional Impacts: China’s Water Resources
•Anticipated decrease river runoff in northern China:
Would worsen existing water shortage and deplete groundwater.
• Increased evaporation in each watershed (up to 15%):
Would increase the likelihood of drought.
• Increased evaporation + changing precipitation patterns:
Would reduce wetlands, lose biodiversity, and increase extinctions.
• Decreased snowpack and glaciation:
Would make western China more drought-susceptible.
Source: China’s National Assessment Report on Climate Change
Regional Impacts: China’s Agriculture
• Warmer weather in the past several decades has changed
agriculture:
- Wheat production has expanded north and west.
-Climate change would result in reduced yield of rice, maize,
and wheat (up to 37% by 2100).
Source: China’s National Assessment Report on Climate Change
Air quality
• Coal meets 2/3 of China’s energy needs.
• The burning of coal produces sulfur dioxide and
nitrogen oxides.
• Urban air pollution accounted for 3.4% of all
deaths in 2001. (Disease Control Priorities Project 2006)
• Beijing raised the sulfur pollution tax and offset
the cost of installing sulfur dioxide scrubbers for
power plants in 2006. (Earth Trends 2008)
Coal miner from
Linfen, China
State
Environmental
Protection Agency
Coal miner
from Kansas,
U.S.
Kansas
Historical
Society
Our Future Depends on Our Choices
Choices require value judgments and
long-term planning
Personal:
Reduce energy use:
Policy:
International agreements
• at home: heating, light
After Kyoto Protocol, new talks in Bali
• drive less, drive efficiently
National and regional laws
As a consumer
support businesses that are
energy conscious
Get political
vote
US Mayors Climate Protection
Agreement
WA voters: by 2020, 15% state power
from renewable energy
China’s goal: 2020, 16% renewable
energy
Summary
• Human-induced climate change is apparent and will
increase into the future.
• Temperature change is more certain than changes in
precipitation.
• Precipitation change can profoundly impact
groundwater, agriculture, drought and flooding.
• Human health effects of coal are both short-term
because of air quality and long-term because of
climate change.
• Today’s choices will impact the future.
The End.
Questions?
University of Washington
Program on Climate Change
Our Future Depends on Our Choices
The technology needed to decrease emissions
while still powering our world exists today
The problem becomes more tractable
if we attack it in wedges.
Possible wedges:
• Wind power
•(50 times current capacity)
• Carbon capture and
storage
•(3,500 Sleipners)
• Efficient Vehicles
• (Change 2 billion cars from 60mpg to 30mpg)
Other wedges: Nuclear power, Reduced vehicle usage, More effiecient buildings, Biomass fuels,
wind hydrogen cars, More efficient power plants, Reduced deforestation, Conservation tillage, More
efficient power plants …
Source: Pacala and Socalo 2004
2004 Emissions per capita
IPCC 4th Assessment Report, 2007
Carbon Dioxide Emissions, 1900-1999
World Resources Institute