Week 12: Human impacts

Question 1

Climate change definition

Answer 1

A change in the statistical properties of the climate system over extended periods of time, regardless of cause

Question 2

Climate fluctuations definition

Answer 2

Changes in climate system over periods shorter than a few decades, e.g El Nino

Question 3

Climate change occcurs due to

Answer 3

Natural processes

Question 4

Examples of natural processes that cause climate change

Answer 4

Volcanism, plate tectonics, anthropogenic impacts

Question 5

Anthropogenic climate change examples

Answer 5

Global warming, ocean acidification, sea-level rise

Question 6

Necessary for habitable planet, otherwise mean surface temperature = -18 degrees

Answer 6

Greenhouse gases

Question 7

Examples of Greenhouse gases

Answer 7

Carbon dioxide, water, methane

Question 8

The greenhouse effect explained

Answer 8

1. Suns radiation travels toward the earth
2. About half is reflected or absorbed by clouds and the atmosphere
3. The rest reaches the earth, where it is absorbed by oceans and land
4. The earth also releases heat back toward space
5. Some of this heat passes directly through the atmosphere
6. But most of it is retained by greenhouse gases

Question 9

Relatively stable rate of emissions of GHGs up until

Answer 9

Industrial revolution (1760-1840)

Question 10

Safe levels of ppm CO2 in planets thermostat

Answer 10

350 ppm

Question 11

Current world ppm CO2 of planets thermostat

Answer 11

422 ppm

Question 12

As CO2 concentration in the atmosphere increases what also increases

Answer 12

Temperature

Question 13

Ocean absorbs what percentage of heat

Answer 13

85%

Question 14

Albedo is

Answer 14

The fraction of light that a surface reflects

Question 15

Highest albedo reflection

Answer 15

Snow (85% reflected)

Question 16

Lowest albedo reflection

Answer 16

Water (7% reflected)

Question 17

Loss of albedo driven feedback loop

Answer 17

1. Albedo reduced
2. Increased absorption
3. Increase in temperature
4. Snow and ice melts
5. Darker surfaces are revealed
6. Repeat

Question 18

Sea level rise largely driven by

Answer 18

Thermal expansion of seawater

Question 19

All animals have a thermal _____ and a thermal _____

Answer 19

Optima, Maxima

Question 20

Exceeding a thermal maxima leads to

Answer 20

Losses in fitness

Question 21

Which species more tolerant to thermal changes

Answer 21

Temperate species

Question 22

Increased CO2 in the ocean equals

Answer 22

Intenser ocean acidification

Question 23

As ocean acidification intensifies, seawater PH is

Answer 23

Lowered

Question 24

Ocean acidification effects calcifiers. For calcifiers to grow, the level of calcium carbonate saturation in SW must be over

Answer 24

Three

Question 25

If the level of calcium carbonate saturation in SW is lower than one, then the conditions are

Answer 25

Corrosive

Question 26

Mechanisms by which calcium carbonate affect fish

Answer 26

1. Physiology 2. Resources 3. Environmental cues 4. Other species 5. Neurology

Question 27

All mechanisms by which calcium carbonate affect fish result in major changes in

Answer 27

Behaviour

Question 28

Fish on acid have their senses

Answer 28

Confused

Question 29

Future oceans will be ______ by 2100

Answer 29

1. Warmer (up to 5 degrees more) 2. More frequent marine heatwaves (20x more likely) 3. Less alkaline (0.3-0.5 ph = 160& increase in acidity) 4. Higher sea level (up to 1-2m) 5. Decreased sea ice 6. Less ocean productivity

Question 30

Absorption of CO2 into seawater forms

Answer 30

Carbonic acid

Question 31

Higher levels of Carbonic acid result in

Answer 31

Bicarbonate and Hydrogen ions being produced > decreased PH of seawater