Welcome! Please get out homework for a stamp: Two questions on RCP’s, bracket map, 10 terms Please...
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Transcript of Welcome! Please get out homework for a stamp: Two questions on RCP’s, bracket map, 10 terms Please...
Welcome!
Please get out homework for a stamp: Two questions on RCP’s, bracket map, 10 terms
Please read the board.
Kahoot practice!
What do these have in common?
Climate and civilization
Human civilizations change when climate changes
20,000 ybp (years before present) ice age: Bering strait freezes, people migrate to the Americas
8,000-7,000 ybp – warming period Mesopotamia flourishing, Jericho established
Mayan civilization – collapses suddenly 950 CE (common era – used to be called AD)Leif Erikson – 950 CE sails to Greenland
Black Death in Europe – famine 1315-1317 – needed to import grain from China
Little Ice age – 1550-1850Irish Potato Famine
Dust Bowl – 1930’s
Mild but persistent La Nina conditions coupled with changes of sea surface temperatures + poor farming practices
SPM 1: Current observations
What details need to be added?
Correlation/causation pg 5
CO2 levels currently
Mauna Loa Observatory - Hawaii CO2 at beginning of Industrial revolution: 280 ppm Current CO2 levels: 398ppm
(watch the movie – when is CO2 highest? Where??? Why???)
Figure 4 – Current observable effects Circle most certain effects What are the implications? Examples from the news? Which is of greatest concern to
Houston/US/you?
SPM figure 5
What are the predictions? How do they get from CO2 to change in
temperature?
Predicting future climate
How do they do that anyway?
Global Circulation model
Global Climate Models: GCM’s
Computer model divides atmosphere into chunks.
Current conditions programmed into each chunk: temp, wind, [GHGs], etc
Computer can generate current and future global temperature averages based on [GHGs]
Limitations of GCMs
Complexity Feedback loops (not included in GCMs)
(+)Melting tundra permafrost and lower geologic formations– 500 billion tons CH4
(+)Loss of albedo effect with ice (-)Increasing albedo effect with clouds (+) Increasing greenhouse effect with evaporating water
Role of ocean and CO2 absorption
Lesson from the Ozone Hole:
1930’s – CFCs invented 1970’s – mechanism of O3 destruction
understood; models of possible effects suggest general thinning of O3 layer
1985 – Ozone hole documented as complete surprise – models were wrong.
1987 – Montreal Protocol ratified
Predictions:
If CO2 goes to 450ppm by 2050, +2oC (3.6oF) CO2 to 550ppm by 2050, +3oC (5.4oF) In 50 yrs, expect 4oC warming (2012 World Bank Report)
CO2 of 350ppm is considered sustainable by climatologists
Tipping point is probably at 2oC (the point at which change due to human activity
brings about sufficient new processes in nature to make any human reversal of the change impossible. )
Homework tonight
Read SPM 2.1 and 2.2 add details to your bracket map.
Studystack.com to review terms: search IPCC terms WHS or carolynklein
Chasing Ice –ice core graphs, effects, glaciers
Big seven effects Change in precipitation patterns More severe weather events (droughts, floods,
extreme hot/cold) Rising sea levels (glaciers melting) Changing seasons – earlier spring and shift of
biomes away from equator Increased insect-borne disease Decreased availability of fresh water Acidification of ocean and bleaching of coral reefs
(H2CO3)
Sea level rise .7 m by 2100
Melting glaciers add water volume to ocean (Greenland ice sheet stores enough water to raise sea level by 5-7 meters)
Thermal expansion creates most of the increase
Where will the environmental refuges go? 50% of global population lives within 100 miles of a coastline.
Fig. 11–9
Shift of biomes away from equatorShift of biomes away from equator
Trees can shift 5mi/10years through seed dispersal
Shift of habitat to higher latitudes and elevations
Potential large loss of biodiversity
© Brooks/Cole Publishing Company / ITP
Don’t forget!