today climate and biotic regions mid-latitude dry climates sub-tropical & mid-latitude humid...
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Today•Climate and biotic regions
Mid-latitude dry climatesSub-tropical & Mid-latitude Humid climates
Mid-to higher latitude cool/cold climates
•Global Environmental ConcernsClimate ChangeGlobal waterAgriculture & food supplySpecies diversity & deforestation
Last time – questions?
•Population movements (migration)
•Urbanization
•Physical Environmental PrinciplesLandformsClimate
•Climate and biotic regionsLow latitude warm and wet
Climate and biotic regions IImid-latitude dry
•Arid & semi‑arid (steppe; desert) Köppen : Bs and Bw (about 20 - 30 degrees n and s)
Desert to Semi-arid grass lands
•Mediterranean: Köppen CsMediterranean ‘scrub’ vegetati
on
“BS & BW” (arid & semi-arid)
“Cs” (Mediterranean)
••
“BS & BW” arid & semi-arid“Cs” (Mediterranean)
© T. M. Whitmore
Bs steppe (semi-arid)climate
Mojave Desert,California
http://www.marietta.edu/~biol/biomes/
biome_main.htm
Thar Desert, India
www.micro.utexas.edu/courses/levin/bio304/biomes/
biomes.html
Grassland, North Dakota
http://www.marietta.edu/~biol/biomes/
biome_main.htm
Grassland, Inner Mongolia
http://people.ucsc.edu/~wxcheng/Inner_Mongolia.htm
Also known as steppe, prairie and plains.
© T. M. Whitmore
Cs Mediterranean (winter rain) climate
Chaparral,California
www.californiachaparral.com
Fynbos,South Africa
www.plantzafrica.com/vegetation/fynbos.htm
Examples of Mediterranean shrublands
Climate and biotic regions IIISub-tropical & mid-latitude
humid climates•Humid sub-tropical
Köppen CaMid-latitude forests
•Marine west coast Köppen CbMid-latitude rain forests
“Ca” (humid sub-tropical)
“Cb” (marine west coast)climates•
“Ca” (humid sub-tropical)“Cb” (marine west coast)
•
© T. M. Whitmore
Humid sub-tropical Köppen Ca
Temperate deciduous forest in the Smokies (left) and northeastern China (below).http://www.marietta.edu/~biol/biomes/biome_main.htm
© T. M. Whitmore
Cb Marine West coast
Temperate rainforest,
British Columbiahttp://www.marietta.edu/~biol/
biomes/biome_main.htm
Temperate rainforest,
New Zealandhttp://www.kevingong.com
Climate and biotic regions IVCool to cold climates
•Humid continental “D” climateswarm summers Köppen Dacool summers Köppen DbTundra (cold summers) Dc Forests
•Polar & sub-artic: Köppen ET, EF Tundra vegetation
•Mountain (highlands): Köppen HVegetation variable with elevation
“D” humid continental“E” polar climates“H” highlands climates•
“D” humid continental“E” polar climates“H” highland climates
•
© T. M. Whitmore
TempRange: ~ 25º C
Humid continental warm Köppen Da
© T. M. Whitmore
Humid continental cool Köppen Db
Taiga,Yosemite NP
http://www.marietta.edu/~biol/biomes/biome_main.htm
Taiga, Siberia
www.micro.utexas.edu/courses/levin/bio304/biomes/biomes.html
Tundra,Alaska
http://www.marietta.edu/~biol/
biomes/biome_main.htm
Paramo,Ecuadorian
Andeshttp://
flora.huh.harvard.edu
The text identifies 4 pressing global issues
•Terrorism•Water supply and quality•Status of women•Economic globalization & worker status
More Global Environmental Concerns
•Global Climate Change
•Global water supplies and quality
•Agriculture & food supply
•Species loss & deforestation
Global Climate Change•See:
Atlas of Climate Change (K. Dow & T. Downing; U. of California Press, 2006) A plug for 2 distinguished friends of your prof
Inconvenient Truth (A. Gore)•Increasing CO2 and other
“greenhouse” gasses •Certain impacts (but the
geography of many are not well known)
Global Climate Change: Causes
•Natural variationsSolar output variations (e.g., “Little
Ice Age” in 1400s to the 1700sVariations in earth’s orbit
(Milankovitch cycles, ice ages)Volcanic eruptions: work to reduce
or increase warming
•Changes in atmospheric greenhouse gas concentrationsFossil fuel use
Global Climate Change: Impacts•Air and ocean temperatures increasin
gRegional differences
•Glacial melting
•Sea level rise
•Altered growing seasons
•Possibly increased storminess & uncertainty
•Changes in global hydrological cycleIncreases in precipitation in total
•Vast regional differences in impacts
Global Climate Change
2005: The New Winner!
http://data.giss.nasa.gov/gistemp/2005/
http://www.nasa.gov/vision/earth/environment/2005_warmest.html
http://maps.grida.no/
Global Climate change impacts on grain cropping (modeled for 2100)Red => reduced potentialGreen => enhanced potential
2 (very different) scenarios of possible climate (rainfall) impacts by 2050
Global water
•Only 2.5% of all water is not salty; 2/3 of that is in polar ice
•Water available for human use is < 0.1% of total water & much of that is remote
•70% of fresh water is used for agriculture
•Increasing population and food needs => potential shortages
•Increasing quality problems
Water Stress
© W.H. Freeman & Co.
Food Supply Increasingly Relies on Irrigation
Agriculture & food supply
•Food production has doubled in past 30 yrs – but needs to do so AGAIN in next 30Total food for an adequate vegetarian diet is sufficient now – if equally distributed
•Gains declining
•Productivity gains not equitable =>
•Regional problems with nutrition
Yields Are Up, But Growth is Slowing
0
1
2
3
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Yiel
d (m
etric
tons
/hec
tare
)
1960 1965 1970 1975 1980 1985 1990 1995 2000
Wheat Yield Rice Yield Maize Yield
Despite Gains, Millions Go Hungry
0
200
400
600
800
1,000
1969-71 1979-81 1990-92 2010
(mill
ion
pers
ons
suffe
ring
from
un
dern
utrit
ion)
Sub-Saharan Africa Near East and North AfricaEast and Southeast Asia South AsiaLatin America and the Caribbean
SSAfrica
SAsia
© W.H. Freeman & Co.
•Loss of 53,000 mi2/yr of tropical forest last couple decades about = area of NC
•Many causes
•Multiple consequences
Tropical Deforestation
Many temperate forests have been lost, but current deforestation and biodiversity loss are most rapid in the tropics.
Species Diversity & human impacts
•BiodiversityDeforestation => species loss
•General human intervention => biosphere disruption
Biodiversity:
Plants
Birds
Biodiversity hotspots. Places around the world where there is: 1) high species diversity; 2) high species endemism; 3) large impact from human activities (Myers et al., 2000).
