Sem#2 Chap 8 Flashcards
1
Q
Signs of a stealth disaster:
A
- Melting glaciers
- Rising sea level
- Hot temperatures
- Frequent, large wildfires
- Devastating floods
- Worsening algal blooms
Future natural disasters will
be more frequent and severe.
Climate change controversy
is partly due to its stealth.
Slow changes are hard to
detect and easily dismissed
2
Q
All objects emit _________.
A
electromagnetic radiation
3
Q
Hotter objects emit ________ wavelengths than cooler objects.
A
shorter
4
Q
Earth absorbs sunlight, which is mostly ________.
A
shortwave radiation
5
Q
Earth radiates longwave radiation into ______
A
space
6
Q
Absorbed energy is balanced with _________
A
radiated energy
7
Q
Greenhouse gases absorb Earth’s ________ , radiated energy.
A
longwave
8
Q
CO2 is _____ times more efficient at trapping heat than water vapor.
A
CO2 is 20 times more efficient at trapping heat than water vapor.
- Contributes 9%–30% of the greenhouse effect
9
Q
CH4 is _____ times more efficient at trapping heat than water vapor.
A
CH4 is 70 times more efficient at trapping heat than water vapor.
* Contributes 4%–9% of the greenhouse effect
10
Q
Weather:
A
atmospheric conditions at a given location and time
11
Q
Climate:
A
average weather conditions over years or decades
12
Q
A region’s climate depends upon:
A
- Average temperature and temperature range
- Amount and distribution of precipitation
- Seasonal variations in temperature and precipitation
- Characteristic weather extremes and storms
13
Q
Temperatures at most latitudes vary over _______
A
a year
14
Q
Insolation:
A
the amount of solar energy at a location
Insolation varies due to Earth’s 23.5° tilted axis.
* N. Pole has no insolation in January.
* N. Pole has 24 hours of daylight in June.
Earth has seasons because of its tilted axis
15
Q
Sunlight intensity varies due
to ______________
A
Earth’s spherical shape
16
Q
At low latitudes:
A
- Steep sunlight angle
- More energy is absorbed
than at high latitudes
17
Q
At high latitudes:
A
- Shallow sunlight angle
- Less energy is absorbed than
at low latitudes
18
Q
Water has a greater ______
capacity than land.
A
heat
- Temperature change in
oceans is less than on land. - Coasts have less temperature
range than inland locations.
19
Q
Climate change occurs over ________
A
decades, centuries, or millennia.
20
Q
Global warming:
A
An average increase in global temperature
21
Q
Global cooling:
A
An average decrease in global temperature
22
Q
Paleoclimates:
A
- Climates that existed before instruments and record keeping
- Scientists use paleoclimate indicators to discern ancient climates.
23
Q
Class Question #1
How is climate different from weather?
a) Climate is about atmospheric gases such as H2O, CO2, and CH4 and their relative concentrations, while weather is only about H2O concentrations.
b) Climate is about how the atmosphere absorbs electromagnetic radiation, while weather is about how the atmosphere reflects electromagnetic radiation.
c) Climate is about how the atmosphere is in a state of accelerated warming, while weather is about how the atmosphere warms and cools over long periods of time.
d) Climate is about atmospheric conditions over decades or millennia,
while weather is about atmospheric conditions at given location and
time.
A
(NOT GIVEN) (Probably D)
24
Q
Fossils:
A
- Indicate climate as far back as 539 Ma
- Fossilized grass pollen indicates warmer climates.
- Fossilized spruce pollen indicates cooler climates.
25
Microfossils
are plankton remains in marine sediment.
* Indicate climate as far
back as 66 Ma
26
Isotopes:
elements with varying numbers of neutrons
* 18O: a heavier oxygen variety
* 16O: a lighter oxygen variety
27
Climatologists examine ______ and _________.
ice cores and isotope ratios.
28
Ice with a low 18O/16O ratio
indicates _________.
cooler climates
29
Ice with a high 18O/16O ratio
indicates _______.
warmer climates
30
Ice O2 ratios indicate_____
~1 Ma old climates.
31
Limestone O2 ratios indicate _______
~500 Ma old climates.
32
Ice cores contain ________
trapped air bubbles.
33
Air bubbles contain _________.
gases from ancient atmospheres
34
Gases are identified, and their
_______ ratios measured.
O2
35
Lab photos of ice cores reveal
annual ________.
snowfall layers
36
These exhibit annual growth rings:
Trees, clams, and coral reefs
37
Growth ring width varies
according to:
* Annual temperature
* Annual precipitation
38
Wide tree rings indicate ________
favorable growing conditions.
* Warm, wet years
39
Narrow tree rings indicate _________
poor growing conditions.
* Cool, dry years
40
Composite tree ring records are
made from ________
many trees.
Living, dead, and buried trees
are used for a composite record.
41
Earth alternates between
_____ and ______ intervals.
warmer and colder intervals.
42
Hothouse intervals are
__________.
warmer periods
43
Icehouse intervals are _________.
cooler periods
44
Temperature anomalies are
comparisons between:
* Temperature at a specific time
* Average temperature over a long time period
45
Paleocene-Eocene climatic optimum:
* Occurred ~55 Ma
* Average global temperature
was 5°–8°C higher than today
46
Cenozoic Era extends from
the _______.
present to 66 Ma
47
Advances of Glaciers:(Where do they move)
glaciers move towards equator
48
Retreats of Glaciers: (Where do they move)
glaciers move towards poles
49
An interglacial period is the
time between:
* The end of the last retreat
* The start of the next advance
50
Pleistocene was (years ago)
2.6 Ma–11,000
years ago.
51
Pleistocene marine sediment
contains _______
oxygen-isotope ratios.
52
Pleistocene Ice Age Oxygen-Isotope Ratios
:Record .....
points to numerous glacial advances and retreats.
53
Causes of Long-Term Climate Change
Greenhouse gases may increase or decrease.
* If CO2 is removed from atmosphere, Earth cools.
* If CO2 is released into atmosphere, Earth warms.
Limestone formation removes CO2.
Volcanic eruptions release CO2.
Tectonic uplift may remove CO2.
Plants and shell-producing organisms remove CO2.
Solar radiation intensity has changed over Earth’s history.
Continents drifting to high latitudes may facilitate cooling.
Variations in ocean currents change heat distribution.
54
Greenhouse gases may increase or decrease.
* If CO2 is removed from atmosphere, Earth cools.
* If CO2 is released into atmosphere, Earth warms.
55
Earth’s orbit and tilt change
________.
cyclically
56
Eccentricity (orbital shape):
* Over 100,000 years, Earth’s
orbital shape changes.
* From more circular to more
elliptical
57
Tilt of the Earth’s axis:
* Over 41,000 years, Earth’s axis tilt changes.
* From 22.5° to 24.5°
58
Precession (axis rotation):
* Over 23,000 years, Earth’s axis rotates.
59
Milankovitch cycles influence _______.
insolation.
60
Up to 25% insolation change
is possible at high latitudes.
* Glacial advances correlate with low insolation.
* Glacial retreats correlate with high insolation.
61
Changes in Earth’s albedo
may cause _______
ice ages.
62
Albedo
is surface reflectivity.
63
Thermohaline circulation
changes may cause
ice ages.
* Freshwater from melting ice
may trigger changes.
64
Feedbacks (In regards to climate, not water )
climate changes that trigger additional changes
65
Positive feedbacks:
amplify a phenomenon that caused it.
* As Earth warms, more liquid H2O evaporates into atmosphere.
* As atmospheric water vapor increases, warming increases.
66
Negative feedbacks:
reduce the phenomenon that caused it.
* As Earth cools, water vapor precipitates out as rain and snow.
* As atmospheric water vapor decreases, cooling increases.
67
Residence times for atmospheric gases:
* The average time spent by a gas within the atmosphere
* CH4 and CO2 remain in circulation longer than H2O.
* Gases with longer residence times have greater climate impact.
68
Class Question #2
How do oxygen isotopes act as climate indicators?
a) Excessive 18O concentrations in ice bubbles indicates lower
atmospheric levels of H2O and CH4, thus a warmer paleoclimate.
b) Ice containing low concentrations of 18O compared to 16O indicates a
cooler paleoclimate.
c) Since 16O is a heavy variety of oxygen, more heating is needed to
evaporate this molecule, thus indicating a cooler paleoclimate.
d) Limestone that contains 18O also has high concentrations of
fossilized plants that required this isotope for transpiration, thus
indicating a cooler paleoclimate.
(NOT GIVEN)
69
Intergovernmental Panel on Climate Change (IPCC):
* World Meteorological Organization
* United Nations
* Evaluates climate studies and summarizes findings
70
IPCC findings:
* Global warming is occurring.
* Human activities are
contributing to warming.
* Certainty is increasing with
every subsequent report.
71
Sea level frequently _____ and
______ relative to land.
rises and falls relative to land.
72
Pleistocene glacial advances:
* Sea level fell as water was locked in advancing glaciers.
73
Tapering off correlates with melting ________.
Pleistocene ice sheets
74
When glaciers melt, water returns to ________
Earth’s oceans.
75
Sea level change varies across ________:
ocean basins
Currents and wind unequally move water around Earth.
76
The Arctic Ocean is _______ covered by sea ice all year
no longer
77
Biological indicators:
Organisms that are sensitive to temperature and seasons
78
Plant hardiness zones are
migrating ________.
northwards
79
Other biological indicators of global warming:
* The date when maple sap starts to flow in spring
* The date when leaves change color in fall
* The date at which cherry blossoms bloom
* The latitudinal ranges of birds, fish, and insects
80
Precipitation distribution and character is changing;
* Some areas are becoming
wetter, while others are drier.
81
Storm severity is increasing:
* The annual number of major cyclones is increasing.
* Cyclones’ rate of intensification is increasing.
* The amount of rain that cyclones produce is rising.
82
Global warming is linked to ______
rising CO2 levels.
83
The Keeling Curve
lect 8 slide #50
84
Two predictions of GCMs:
* Earth’s current warming trend
* No warming if greenhouse gases remained ~300 ppm
85
The Carbon Budget
Red arrows indicate sources that release carbon into atmosphere.
Green arrows indicate sinks that remove carbon from atmosphere
86
Carbon sources release ________ gases
release greenhouse gases.
87
Carbon sinks _____
remove greenhouse gases.
88
Sequestration:
the removal and storage of carbon
* Carbon is stored in the
hydrosphere or geosphere.
89
Rainforests are shrinking:
* Slash and burn activities immediately release CO2.
* Clear-cutting for farms and ranches eliminates these sinks.
* Deforestation accounts for ~8%–10% of carbon emissions.
90
Prairies and grasslands are disappearing:
* Plowing immediately releases CO2.
* Crop cultivation reduces these sinks.
91
The Amazon rainforest stores an immense amount of ______.
carbon
92
Carbon has three isotopes:
14C, 13C, and 12C.
93
12C is ______
carbon’s most common isotope
94
13C is found in _______
found in volcanic gases
95
14C is ________
a radioactive isotope, and a tiny portion of all carbon.
96
Fossil fuels contain no _____.
14C
Their 13C/12C ratio is < atmospheric 13C/12C ratio
97
Volcanic gases, ratio compared to atmospheric ratio
* Their 13C/12C ratio is > atmospheric 13C/12C ratio.
98
Fossil fuel combustion creates unique carbon fingerprints: (ratios)
No 14C, and low 13C/12C ratios
99
Class Question #3
What do global climate models predict if greenhouse gases remained at
preindustrial levels?
a) Earth’s atmosphere would exhibit no significant warming.
b) Earth’s atmosphere would contain high concentrations of 13C.
c) Earth’s atmosphere would cool and contract, resulting in more
severe weather events.
d) Earth’s atmosphere would absorb the excess carbon released from
anthropogenic sources.
(NO GIVEN ANSWER)
100
Researchers use GCM to ______
predict future scenarios.
101
High carbon scenario:
* 1,000 ppm by 2100
* Atmospheric temperature
increases by ~4.5 °C.
102
Medium carbon scenario:
* 620 ppm by 2100
* Atmospheric temperature increases by ~ 3.7 °C.
103
Low carbon scenario:
* 475 ppm by 2100
* Atmospheric temperature increases by ~2.2°C.
104
High emission scenario: Sea level rises by _____
by 2 m.
105
Medium emission scenario: Sea level rises by ____
Sea level rises by 0.8 m.
106
Low emission scenario: Sea level rises by ____
Sea level rises by 0.2 m.
107
~____% of humanity lives near
coasts < 10 m above sea level.
10
108
Coastal areas are at
increasing ______
risk of flooding and destruction.
109
Humanity depends on freshwater from a variety of sources:
* Rivers, lakes, and aquifers
* Snow and ice from mountains
110
Mediterranean climate
rainfall decreases by %
20%-40%.
111
Precipitation increases in
other places by %
10%-60%.
* Temperate and polar
climates
* Along the ITCZ
112
Most warming will occur in
______ and ______ regions.
Arctic and subarctic regions.
113
Polar amplification:
* Albedo drops as ice and snow melt.
* More solar energy is absorbed.
114
Permafrost thawing creates a
positive feedback:
* Permafrost is frozen all year.
* Warming thaws permafrost.
* Thawing permafrost decays,
thus releasing carbon.
Infrastructure is damaged as
permafrost thaws
115
Permafrost Thawing
Infrastructure repairs as a result
of thawing cost billions.
Sediment and slopes become
unstable as permafrost thaws.
Risks from slumps and
landslides increase.
116
Polar Bear Populations Decrease as _______
Sea Ice Melts
Polar bears use sea ice to hunt for seals.
Melting ice reduces hunting areas for bears.
117
Aedes aegypti:
a mosquito transmitting yellow fever, dengue, and Zika
118
Anopheles:
a mosquito transmitting the parasite that causes malaria
119
Sandflies:
causes leishmaniasis
120
Ticks:
transmits Lyme disease and encephalitis
121
The pH scale measures
acidity:
* pH < 7 is an acid.
* pH > 7 is a base.
122
Coral Bleaching Is Increasing(Read)
Coral under stress expel algae and turn white.
Coral die if bleaching conditions persist.
Warmer water and lower seawater pH cause coral bleaching.
Recent massive bleaching:
* ~50% of coral died in the Caribbean in 2005.
* ~50% of Australia’s Great Barrier Reef had died by 2019
123
Fisheries Are Degrading
As seawater warms and pH falls, zooplankton migrate or die.
Fish that depend on zooplankton must also migrate or die.
Maximum catch potential is shifting poleward.
Fish stocks in southern oceans are expected to decline.
Fish stocks in northern oceans are expected to increase.
124
Positive feedback accelerates
_______.
global warming
125
Thermohaline circulation transfers _______.
heat across latitudes
126
Atlantic thermohaline circulation:
* Slowed by ~15% since the mid-20th century
* Possibly due to Greenland ice sheet melting
127
Tropical cyclone wind speeds increase with _______.
global warming.
128
Polar front is likely to shift ________:
northward
* Number of mid-latitude cyclones may decrease.
* Nor’easters may strengthen in warmer ocean water.
129
Intensity of heavy rains will increase with _________
global warming
130
Heat waves:
higher-than normal temperatures
* Lasting days or weeks
131
If global temperatures _____,
heat waves will increase.
rise
132
Bell curves illustrate a shift
to ________.
extreme temperatures
133
Hot zones, temperature:
Place with average annual
temperatures > 29°C
134
Droughts worsen as soil moisture ________
as soil moisture evaporates.
135
Hadley cell expansion:
Creates arid conditions in semiarid regions
136
Class Question #4
What happened to the length of the growing season in Iowa from 1990
to 2012 (hint: consider plant hardiness zones)?
a) It shortened by 20 days.
b) There was no significant change.
c) It lengthened.
d) It lengthened from April to May but shortened from June through
September.
(Not given)
137
Reducing fossil fuel use is
challenging:
* World demand is high.
* They have high energy densities.
* Infrastructure already exists to move these resources.
* They are relatively cheap.
138
Reducing fossil fuel use:
* Energy conservation
* Encouraging alternative energy resource use
139
Carbon-neutral sources have
no carbon footprint: Examples:
* Solar, tidal, geothermal, wind, hydropower, biofuels
* Nuclear power
140
Adopting renewable energy
sources is challenging:
* Infrastructure may need to
be constructed.
* Wind and solar are
intermittent resources.
* Energy storage research and
development is needed.
141
Carbon capture and
sequestration:
* Trapping CO2 at its emission
source
* Pumping liquefied CO2 into
underground rocks
142
Cap-and-trade policies:
* A carbon emission cap is
passed by lawmakers.
* Companies trade credits to
emit over the cap.
* Credits are traded and have
monetary value
143
Adaptation tactics:
* Building seawalls to prevent
flooding
* Broadening wetlands to
lessen storm surge impacts
* Improving air conditioning
technologies
* Improving irrigation
methods
* Developing new crop
varieties
