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What is the scientific consensus on climate change and impacts?
University of WashingtonProgram on Climate Change
Who we are…
Graduate Students, University of WashingtonProgram on Climate Change• Lia Slemons• Robert Hahn
"I know of no safe repository "I know of no safe repository of the ultimate power of of the ultimate power of
society but thesociety but thepeople. And if we think them people. And if we think them not enlightened enough, the not enlightened enough, the
remedy is not toremedy is not totake power from them, but to take power from them, but to inform them by education."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
Source: Murray ca. 2005
GHG
• GHGs reradiate some escaping energy back towards the surface, making the temperature warmer
GHG
• Sunlight heats the earth
• To maintain an equilibrium, Earth reradiates the energy to space• Greenhouse gases absorb this energy
GHG
Human sources of Greenhouse Gases
Source: Earth Trends 2008
• ~50% of CO2 emissions to atmosphere are currently from humans
• Fossil fuel burning represents 81% of human sources of GHGs
U.S.
186.1
EuropeanUnion
127.8Russia
68.4Ukraine
21.7Poland
14.4
China
57.6Japan
31.2
Australia
7.6
India
15.5
Kazakhstan
10.1
South Africa
8.5
Canada
14.9
Mexico
7.8Trinidad and Tobago
United Arab Emirates
Kuwait
Total CO2 emissions
since 1950 in billions of tons
Time, 2001
Global Energy trends
• 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.
Earth Trends 2008
CO2 1958 to present
Year
CO
2 (p
pm)
• CO2 concentrations have increased since 1958
• Estimated increase of about 30% since 1850
(280 ppm to 370 ppm)
Instrumental Temperature Record
Source: NOAA
Δ T
empe
ratu
re (
C )
Δ T
empe
ratu
re (
F )
More Evidence: Ice Cores
• Ice layers preserve information about each year Sources: NOAA, GISP2 websites
-10
-8
-6
-4
-2
0
2
4
050
,00
0
10
0,0
00
15
0,0
00
20
0,0
00
25
0,0
00
30
0,0
00
35
0,0
00
40
0,0
00
Years BP
Te
mp
era
ture
diffe
ren
tial, ºC
180
220
260
300
340
380
CO
2 c
on
ce
ntr
ati
on
, pp
mv
Temperature differential
CO2 concentration
Ice Core EvidenceCO2 and temperature, 420,000 BP to present
Source: various, (1) Vostok assembled by Davies 2000, (2) GISP2
Today
2050 2100??
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
Source: IPCC ARW4, Session 1, Figure 10.9
“Will the wet will get wetter and the dry will get drier?”--Dr. Isaac Held
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, ChinaState Environmental Protection Agency
Coal miner from Kansas,
U.S.Kansas
Historical Society
Our Future Depends on Our Choices
Policy:
International agreements
After Kyoto Protocol, new talks in Bali
National and regional laws
US Mayors Climate Protection Agreement
WA voters: by 2020, 15% state power from renewable energy
China’s goal: 2020, 16% renewable energy
Personal:
Reduce energy use:
• at home: heating, light
• drive less, drive efficiently
As a consumer
support businesses that are energy conscious
Get political
vote
Choices require value judgments and long-term planning
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 The problem becomes more tractable if we attack it inif we attack it in wedges.
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 …
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)
Source: Pacala and Socalo 2004
2004 Emissions per capita
IPCC 4th Assessment Report, 2007
Carbon Dioxide Emissions, 1900-1999
World Resources Institute