Write a one sentence overview on what we will learn today based on this picture.
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Transcript of Write a one sentence overview on what we will learn today based on this picture.
Write a one sentence overview on what we will learn today based on this picture.
Climate Change:Fitting the pieces together
Atmosphere
Ocean
Polar Ice
Human/natural influence
Ecosystem
Present day observations
Change in Temp
Past Data: How do we know?Data Collection!
Tree ring data Ice Core
Fossil Evidence Patterns and chemical comp in coral skeletons
Hadley Centre, 2003
Surface, balloon, & satellite temperatures agree
Temperature increases are nonuniform: higher mid-continent, highest of all in far North. (These are observations, not modeling results.)
J. Hansen et al., PNAS 103: 14288-293 (26 Sept 2006)
2001-2005 mean ∆Tavg above 1951-80 base, °C
Evaporation & precipitation are increasing
NCDC, 2000
Effect is not uniform; most places getting wetter, some getting drier.
GLACIERS ARE MELTING
Muir Glacier, Alaska, 1941-2004
NSIDC/WDC for Glaciology, Boulder, compiler. 2002, updated 2006. Online glacier photograph database. Boulder, CO: National Snow and Ice Data Center.
August 1941 August 2004
Coastal glaciers are retreating
The most startling evidence yet…
The melting of the Arctic
MELTING OF THE ARCTIC.
New predictions
Satellite observationsMean IPCC predictionMost likely change
(melt)IPCC range
Actual observed melting
it has melted nearly 80 YEARS ahead of when
scientists predicted
YEAR
% c
han
ge in
ice
cover
WEATHER IS BECOMING MORE EXTREME
MAJOR FLOODS PER DECADE
Australia fires spark calls for CLIMATE
ACTION“ ”- Washington Post, March 1, 2006
The trend has been upward everywhere.
Wildfires by continent & decade from 1950
Westerling et al., SCIENCE, 18 August 2006
Correlation of wildfire increases with temperature is clear
Running, Science, 18 August 2006
This works in part through soil moisture
Australia suffers worst drought in
1,000 years “ ”
- Guardian UK, Nov 7, 2008
SEA LEVELS ARE RISING
Three Year Average
Satellite Altimetry
Year
Sea L
evel C
han
ge (c
m)
1993-2003 ≈ 35 mm = 3.5 mm/yr; compare 1910-1990 = 1.5±0.5 mm/yr.
Sea-level is risingmm
ACIA, 2004
Further evidence of changing climateObservations Show…
Evaporation & rainfall are increasing;
Coastal glaciers are retreating;
Mountain glaciers are disappearing;
Permafrost is thawing;
Sea ice is shrinking;
Greenland is melting;
Sea level is rising;
Species are moving.
Why should we care?
Temp expected to increase by 2-13o F by 2100
Oceans absorb more CO2
Some expected changes… Warmer temps mean mosquitoes, ticks and rodents expand their range
Less snow—people who depend on snow-fed reservoirs for water
5-20% inc. in crop yield, but more prone to failure with increase temp and decrease in precipitation
OCEANS ARE ACIDIFYING
FORESTS ARE THREATENED
Coral reefs are bleaching
threatens the survival of
SMALL ISLANDS
Already, the president of the Maldives has created an investment fund from tourism earnings so the nation can buy a new homeland in Sri Lanka and India, for its citizens in case of massive flooding.
Sea-level rise projections : a few inches to a few feet
•2 ft: U.S. would lose 10,000 square miles•3 ft: Would inundate Miami•Affects erosion, loss of wetlands, freshwater supplies•Half of the world’s population lives along coasts
What changes climate?
Changes in:Sun’s outputEarth’s orbitDrifting continentsVolcanic eruptionsGreenhouse gases
Earth’s Atmosphere
CO2 is found in troposphere.
THE GREENHOUSE EFFECT
“Greenhouse effect” Increasing greenhouse gases trap more heat
Greenhouse gases
Nitrous oxide
Water
Carbon dioxideMethane
Sulfur hexafluoride
Atmospheric CO2 Levels
http://climate.nasa.gov/key_indicators
CO2 CONCENTRATIONS ARE OFF THE CHARTS
CO2 in PPM
TEMPERATURE
Years
Part
s p
er
Million
C
O2
TODAY: 387ppm
550ppm? More?
EARLY 1900S
LAST ICE AGE
Where we’ll be mid-century if we keep this up
390ppm CO2
today:
Raising by 2ppm/year
The Industrial Revolution changed our energy consumption
Combustion Reactions produce CO2
Combustion Reaction:CH4 + O2 CO2 + H2O
(Fossil fuel)
CO2 IN THE ATMOSPHERE
WE’RE HERE: 387
WE NEED TO BE HERE: 350
PA
RTS
PER
MIL
LIO
N C
O2
YEAR
?HOW DO WE GET TO
Can we fix it? Yes we
can!!
AND IMPLEMENTING AND IMPLEMENTING
A A THOUSAND THOUSAND
DIFFERENT DIFFERENT SOLUTIONSSOLUTIONS
IT MEANS PLANTING TREESINSTEAD OF CLEAR-CUTTING
RAINFORESTS
IT MEANS PUTTING UP WIND TURBINESINSTEAD OF COAL PLANTS
PA
RTS
PER
MIL
LIO
N C
O2
YEAR
Phase-out of coal by 2030
Improved forestry and soil
Reduced oil/gas use
GETTING TO 350
Spread the word…
http://www.youtube.com/watch?v=zORv8wwiadQ