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Flashcards in BIO220 Lecture 22 Deck (61):
1

Earth entered __th major ice age 2.58 million years ago

5

2

Ice age has alternating ___ and ___ periods

glacial & interglacial
- sinusoidal temperature changes

3

We are exiting the interglacial period in the next...

10-50 thousand years

4

long-term prediction of climate? short-term?

long-term: entering glacial period
short-term:

5

4 pioneers of climate prediction

- Tyndall
- Arrhenius
- Bjerknes
- Richardson

6

Tyndall's contribution

How different gasses absorb radiation
- greenhouse effect of water vapour (how water holds heat)
- diff gasses store diff amounts of heat

7

Arrhenius's contribution

Overall effect of CO2 as a greenhouse gas
- double CO2 = 4*C increase in global temperature
- alternating glacial & interglacial periods due to fluctuations in CO2 concentration
- coal burning will fend off next ice age

8

Milankovich cycles

interglacial & glacial cycles based on wobbling of earth's axis and our position in the universe

9

Why do we have alternating glacial & interglacial periods?

- Arrhenius: CO2 concentration
- Milankovich: wobbling of earth's axis
^ both contribute

10

Bjerknes's contribution

Primitive equations for modelling weather

11

Richardson's contribution

Calculate first numerical weather prediction

12

ENIAC's breakthrough prediction in 1950

predicted 24h of weather in 24h

13

What can we predict far in advance: weather or climate?

climate

14

why can't we predict weather far in advance?

- chaotic nature
- estimation & computation limitations

15

CLIMATE

statistics of weather

16

How to predict future climate?

Look at mean weather for current month + standard deviations -> project forward.
e.g. April 2014 is 10*C +- 5*C, so April 2020 will probably be about the same

17

IPCC

intergovernmental panel on climate change

18

Backward prediction (climate)

Use method of predicting future climate for data in 1990, and see if predicted result match real result of 2000
- allow us to see if our method of prediction is good

19

Different groups are studying climate around the world. What do they do?

- model building
- collect data on past climates
- validation & approve causes

20

IPCC was established by __ in __

UN;
1988

21

What does the IPCC do?

Review all available research and get a central central opinion -> core findings on climate that everyone can agree
- does not do its own research

22

Why was IPCC established?

avoid "alarmist" projections by independent scientists

23

Albedo effect

Cools earth; reflection of solar radiation back into space

24

Greenhouse effect

Heats earth; traps infrared radiation emitted by the Earth

25

__ of the solar radiation is absorbed by the Earth's surface

1/2

26

___ radiation is emitted from Earth's surface

infrared

27

Past climate cooling is associated with... (Albedo effect)

uplift of mountain ranges -> snowy regions

28

What reflects the most light? What problem does this cause?

Snow > crops > forest > water;
When snow (75%) melts to water (5%) due to heat, Earth with heat even MORE

29

Keeling's annual measurement of CO2 in Hawaii showed...

sinusoidal fluctuations
- drop due to northern summer (photosynthesis)
- rises due to northern winter

30

Keeling's measurement of CO2 in Hawaii showed...

upward trend if you put many years together

31

Major greenhouse gasses ranked by the relative effect per molecule (least -> most). Also list their sources.

1. H2O
2. CO2 (respiration, combustion)
3. CH4 (anaerobic organic decomposition, grazing)
4. N2O (denitrification, combustion)
5. CFC (refrigerants, spray can)

32

Removing which greenhouse gas would have the biggest impact on improving Earth? Why?

CO2;
Even though it does not have as much of an effect as the other greenhouse gasses, there are many more molecules of it

33

Which counties are the biggest emitters of CO2?

- China (overall)
- Canada & Australia (emission/capita)

34

Why are Canada & Australia such big emitters of CO2?

- mining
- oil extraction
- forestry?

35

Trend: global avg temp

increase

36

trend: global avg sea level

increase

37

trend: northern hemisphere snow cover

decrease

38

Trend: temp changes by region

- overall: increase
- each reach increase slightly differently

39

What is mostly likely the driving factor of temp increase?

CO2

40

Trend: current CO2 levels

exponential increase
- before: sinusoidal
- higher than ever before

41

Manifestations of current climate change

1. exponential increase of CO2
2. costal areas of Greenland & Antarctica loosing ice
3. sea-level rise
4. loss of Arctic sea ice

42

Rising sea level ___ previous estimate. Data from...

matches;
IPCC & Merrifield (independent group)

43

According to current predictions, we will be ice-free in the Arctic by...

2050

44

Sakura flowering time data shows...

Spring was getting here later and later, but suddenly started getting here earlier

45

Why is the cause of warming not due to increased solar activity? (which data does not match)

- nighttime temp rising faster than daytime ones
- troposphere heating & stratosphere cooling

46

Warming trends that we see

- poles warm faster than mid-latitudes
- winter warm faster than summer
- nighttime temp rising faster than daytime ones
- troposphere heating & stratosphere cooling

47

Why is the cause of warming not just due to solar & volcanic activity?

Models:
1. solar & volcanic activity
2. greenhouse gas activity
3. all of the above

Impose model on real data: 3 matches the best

48

Research from Berkley on climate heating results

- graph temperature of earth
- put best-fit line
- best fit line = activity from CO2 and volcanic eruptions

49

Effect of volcanic eruptions

- release lots of soot
- reflect solar radiation back to atm
- cools earth dramatically (set global warming back 10 years)
- "year summer never came" -> bad for farming

50

Who were the Berkley scientists funded by?

Koch Brothers (skeptics, oil industry) & Gates Foundation

51

post-____rise in temperature is due to ___, says IPCC

1956;
humans

52

most of the globe (2000-2010) warmed up by __C compared to 1900-1910

2

53

80 years from now, Earth's temp will increase about __C

4-6

54

Rising temp effects on human health

- some disease will die because too hot for vectors to survive (malaria)
- malnutrition
- deaths from extreme weather
- cardio-diseases due to bad air quality
- reduce cold-related deaths
- more diarrheal diseases

55

Weather events will become more extreme because...

atmospheric heat engine will be more powerful

56

limitations of global climate model

- hard to model clouds
- coupling of land-ocean atmospheres weak
- can't make small-region predictions

57

GCM

global climate model

58

What was the highest temp in the past? When?

Paleocene-Eocene Thermal Max (PETM), 56 MYA
- 6C increase in 20 000 years
- much higher temp than now
- spiked in both temp and CO2

59

PETM was most likely due to...

- some positive feedback mechanism
- melting of frozen methane from ocean (clathrate gun hypothesis)

60

PETM events

- mass extinction of oceanic organisms
- oceans acidified from CO2 -> animals can't make carbonate shells
- migration of species & biomes
- dwarfing of mammals
- leaf sizes shrink, increased insect
- wet tropical forest -> dry savannah
- arctic -> swamps

61

Bergmann's rule

- larger organisms in colder climates
- smaller organisms in hotter climates