THREE THINGS…

1. The Earth Sciences Survey. Follow the link on the VISTA homepage. Username: saess, password: earth. You get: THE 2nd HALF OF THAT 1% EXTRA CREDIT!

2. The EOSC 112 End-of-term Survey. It’s in “Assessments” in VISTA, where all the other surveys and quizzes have been You get: POWER & INFLUENCE!

3. The instructor & course evaluation. Link has been emailed to you by UBC central You get: MORE POWER & INFLUENCE!

Tuesday, Dec. 22nd, 8:30-11:00, Wood 2You’ll have 2.5 hours. Most of you will not take the full 2.5 hours.

Question formats will be like the midterms.

We will schedule TA hours in the few days before the final exam. Hours will be posted on VISTA

If you want to view your midterm exams:Midterm 1: contact Sara HarrisMidterms 2 & 3: contact Roger Francois

On the electromagnetic spectrum, as you move from x-rays to radio-waves, what happens to wavelength and frequency?

a) Wavelength increases, frequency decreases

b) Wavelength decreases, frequency decreases

c) Wavelength increases, frequency increases

d) Wavelength decreases, frequency increases

Considering only the reflectivity of different environments, how would Earth's surface

temperature change if deserts expanded to replace forests?

a) Surface temperature would increase

b) Surface temperature would decrease

c) Surface temperature would stay the same

What would happen to the temperature at the North and South Poles if atmospheric

circulation stopped (no wind)?

a) Temperature at the poles would increase

b) Temperature at the poles would decrease

c) Temperature at the poles would rapidly increase and then decrease

d) Temperature at the poles would not change

Given this diagram of the Earth, which of the latitudes marked (A, B, C, D, E) are typically

rainy? Choose the BEST answer.

a) A, C, and E

b) B, D, and E

c) A, B, and C

d) A and C

e) B and D

Given this diagram of the Earth, at which of the latitudes (A, B, C, D, E) does air typically

sink towards Earth's surface? Choose the BEST answer.

a) A, C, and E

b) B, D, and E

c) A, B, and C

d) A and C

e) B and D

Imagine you’re planning to sail across the Pacific Ocean, from X to Y on the map below, in a boat

with no motor. Which of the marked routes is likely to have the most favourable wind for sailing?

(Note that route A goes around Antarctica, off the map for a while).

a) Route A

b) Route B

c) Route C

d) Route D

Look at the small wiggles in the graph. How much time passes between adjacent peaks?

a) Half a year

b) One year

c) One and a half years

d) Two years

What do you think is causing the small, short term wiggles?

a) Changes in temperature

b) Changes in pollution

c) Changes in ocean currents

d) Changes in photosynthesis

e) Changes in volcanic eruptions

a) Volcanoes can add greenhouse gases to the Earth’s atmosphere

b) The formation of mountain ranges can remove greenhouse gases from the atmosphere

c) The changing position, shape and size of the continents on the surface of Earth affects how much light it reflects

d) All three above are correct

e) Two of the three above are correct

Plate Tectonics affects Earth’s climate because…

New seafloor forms at mid-ocean ridges, how does this affect the size of the Earth?

a) The size of Earth increases gradually

b) The size of Earth stays the same but its surface “wrinkles”, producing mountain ranges and ocean basins

c) The size of the Earth stays the same because old seafloor is destroyed at the same rate as new seafloor forms

d) The size of Earth stays the same because it is cooling and shrinking at the same rate new seafloor forms

a) No effect

b)  India would get warmer, but the rest of Earth would be unchanged

c) The whole Earth would get warmer

d) India would get colder, but the rest of Earth would  be unchanged

e) The whole Earth would get colder

Imagine that an unusually high rate of volcanic eruptions occurs in India for a million years.

 What affect would this have on Earth's surface temperature?

a) The rotation of the Earth

b) Continents floating on lava

c) The Earth's magnetic field

d) Convection beneath the Earth's surface

e) Earthquakes

What causes continents on Earth to move?

Which of these is NOT essential for all living organisms?

a) Liquid water

b) A source of carbon

c) A source of oxygen

d) A source of nitrogen and phosphorus

e) A source of energy

The primary difference between prokaryotes and eukaryotes is:

a) Only prokaryotes have the ability to photosynthesize

b) Prokaryotes lack a nucleus containing their genetic material

c) Prokaryotes can be both unicellular or multicellular

d) All of the above

Which is FALSE?

a) Low in winter, even though there is a lot of nutrients, because light is low.

b) High in spring because there is more light and still a lot of nutrients in surface water

c) Even higher in summer because there is even more light and nutrients in surface waters

d) Lower in summer because stratification prevents the supply of nutrients from deep to surface waters

The growth rate of phytoplankton off the coast of British Columbia is:

Consider the following food chain in a forest ecosystem

Acorn > Squirrel > Fox > BacteriaWhich of these three organisms has group has

the largest biomass? a) Acorns

b) Squirrel

c) Fox

d) Bacteria

Goals for today

1. DESCRIBE evidence supporting the idea that humans have a discernible influence on climate.

2. DESCRIBE most likely impacts of climate change within your expected lifetime based on IPCC scenarios and regional climate impact assessments.

Modern Climate:

RELEVANCE

Temperature change: the past 150 years

Where does the evidence come from?

Thermometers Weather balloons Satellites

Regional differences: Surface T

IPC

C, 2

00

7

1979-2005

Clicker Q: Can solar variability explain the temperature increase in the second half of the 20th century?

Temperature

Sunspots

A. Yes, because fewer sunspots mean more solar radiationB. Yes, because fewer sunspots mean less solar radiationC. No, because fewer sunspots mean more solar radiationD. No, because fewer sunspots mean less solar radiation

Could solar variability explain it?

Evidence: Increases in Greenhouse Gases

http://www.ipcc.ch/ IPCC, 2007

Compare pre-industrial valuesto present-day values

Clicker Q: The primary human activities that add CO2 to the atmosphere are burning fossil fuels and deforestation. How would you expect these activities to affect atmospheric oxygen (O2)?

A. O2 would increaseB. O2 would decreaseC. O2 would stay the same

O2 has decreased at the rate expected from fossil fuels burning and land use

changes

IPCC, 2007, Fig 2.3

Clicker Q: The primary human activities that add CO2 to the atmosphere are burning fossil fuels and deforestation. How would you expect these activities to affect the ratio of 13C/12C in the atmospheric CO2? HINT: plants prefer 12C over 13C.

A. 13C/12C would increase (get heavier)B. 13C/12C would decrease (get lighter)C. 13C/12C would stay the same

Francey et al., 1999

1800 1900 2000

13 C

-6.0

-7.0

-8.0

1980 2002

13C/12C has decreased as fossil and forest carbon are added to the

atmosphere

ObservationsClimate models w/natural & human forcing

Climate models w/natural forcing ONLY IPCC,

2007

Evidence:Global temperature, sea level &

snow cover

IPCC, 2007

Past 100 years: T 0.074 ºC/decade

Past 50 years: T 0.13 ºC/decade

Clicker question: If all the ice on Greenland were to melt, sea level would rise about 7 metres. Would the building you live in be above sea level?

A. YesB. NoC. Not sure – it’d be closeD. I have no idea

Church&White, 2006; IPCC, 2001; RealClimate.org

IPCC models from 2001 for the next 100 years

Zoom in…next slide

Church&White, 2006; Cazenave&Nerem, 2004; IPCC, 2001; RealClimate.org

Zoom in on IPCC models from 2001… Data appear to follow UPPER predictions for sea level rise

Future? How much warming?

IPCC, 2007

CLIMATE SENSITIVITY: How much would global average temperature increase IF CO2 concentrations DOUBLE (from pre-industrial values)?

CO2 X 2

IncreasedForcing = 4 W/m2

IncreasedTemperature

= 3⁰C

IPCC,2007

FUTURE? Modeled surface warming: About 1.8 - 4.0 ⁰C warming by 2100 (scenario dependent)COMMITTED WARMING:About 0.6 C ⁰

Future? Modeled temperature change in the next centuryVancouver: 0.5-1ºC warmer within ~20 years

Vancouver: 2.5-3ºC warmer within ~90 years

IPCC, 2007

Vancouver: rainier winters (December, January, February)

Vancouver: drier summers (June, July, August)

IPCC, 2007

Future? Modeled precipitation change in the next century

Summary: Modern Climate • Evidence from the chemical composition of the atmosphere implicates human activities as the source of increased atmospheric CO2, increasing temperatures.• Today: global temperature is rising, sea level is rising, concentrations of greenhouse gases are increasing.

• RATES of change in climate parameters are unprecedented. VALUES of greenhouse gas concentrations are higher than anything in at least the past 650,000 years.

• IPCC, 2007. “…very high confidence [90%] that the globally averaged net effect of human activities since 1750 has been one of warming.”• Future projections: higher T, CO2, sea level; drier subtropics, wetter tropics/temperate regions