Lecture 30 Flashcards
1
Q
Rising CO2 Levels
A
- contributing to the rapid increase of greenhouse gasses in our atmosphere
- rate not seen for millions of years
- have potential to match lethal pH change of Permian Extinction
- contributes to global warming, marine dead zones and acidification, extreme rainfall changes, range changes in organisms
- it is a known mass extinction mechanism
2
Q
Greenhouse Effect
A
- solar radiation passes through clear atmosphere
- some is reflected by atmosphere and earth’s surface
- some absorbed by earth and warms it
- some infrared radiation absorbed and reemitted by greenhouse gas molecules–>warming of surface and troposphere
- some infrared radiation passes through atmosphere and lost in space
3
Q
US Consumption
A
-at current moment ~80% of energy we get results in CO2 emission
4
Q
Greenhouse Gases
A
- CO2, methane and water vapor
- CO2 major concern because so much is produced
- methane will be problem if CO2 generated temperature rise releases methane from tundra and marine stores
5
Q
Keeling Curve
A
- expected to see the annual cycle
- what he saw was the curve just continued to increase
- unprecedented rate of CO2 emissions-crazy increase in levels
6
Q
Effects of Warming Now Observed
A
- higher thermometer readings in Northern hemisphere
- local extinctions
- species moving northward, none south
- species moving to higher elevations, none to lower
- destruction of trees by insect pests moving north
- earlier plant blooming dates
- more frequent violent weather, including floods
- loss of ice cover in Arctic Ocean, polar bears drowning
- accelerated melting of glaciers
- sea level rise-due both to glacier melting and expansion of warming oceans
7
Q
Rapid CO2 Release
A
- from massive releases of lava have caused mass extinctions
- permian, triassic, paleocene
- could be the same for us
8
Q
CO2 and Seawater
A
- as CO2 concentration in seawater rises, pH falls
- sea water becomes more acidic
- low pH dissolves CaCO3 which is in many marine shells and skeletons
- expected to fall as low as 7.8 by end of century and has already fallen to 8.1 from 8.2
- this will have lethal effects on many skeleton and shell bearing species like corals and mollusks
- causes bleaching and productivity loss in coral reef builders
- correlations between shell dissolution and water chemical properties in a tropical estuary
- ocean acidification-induced food quality deterioration constrains trophic transfer
9
Q
Plain Water
A
-1/6th of world depends on glaciers for water
10
Q
Non Sustainable Development and Consumption
A
- extinction of exploited organisms
- habitat degradation
- habitat loss
- pollution and global warming
- ecological changes
11
Q
Jellyfish and Tuna Example
A
- big fish like tuna hold down jellyfish because they eat them so jellyfish are suppressed by these vertebrates but if you kill all these fish and turtles ;you get a shift because large jelly fish catch small fish so small fish don’t grow into big fish.
- introduce fishermen and things won’t return to normal and it fucks shit up
- we make it worse by ballast water exchange
- warming could possibly cause a return to early cambrian ocean ecosystem
12
Q
Dead Zones
A
- correlate with human impact
- lots of areas of low oxygen sea water which make oceans less
- Gulf of Mexico because Mississippi brings down lots of nitrogen and fertilizer and bacteria suck up oxygen so there’s not enough left able to support diverse life
13
Q
Bacterial Mat
A
- size of Greece
- largest mass of life on earth
- found in pacific
- anerobic
- precambrian-like
14
Q
Recreating
A
-not just cambrian Jellyfish world, but precambrian microbial slime world or one that resembles the permian extinction ocean
15
Q
New Geological Force
A
- humans
- magnitude of our impact suggests this
- proposed that our era be called Anthropocene because of its geological and ecological impacts
- now great enough to be recorded in fossil record
