People and Problems Flashcards
1
Q
How much of earth’s land has been transformed by human action?
A
between one-third to one-half of all of earth’s land
2
Q
There has been a __% increase in atmospheric CO2 since the industrial revolution, and ___ of the bird species have gone extinct
A
30%
one-third
3
Q
Human actions have 2 types of impacts. What are they? Give some examples for each type
A
- direct impacts
- land use and land cover change
- habitat fragmentation
- Biodiversity loss and extinction
- Loss of resources - Indirect impacts
- Climate change
4
Q
write out the flow chart in slide 4
A
.
5
Q
Humans rely on 3 systems to supply their food:
A
- Croplands
* Produces grains
* Provides 77% of the world’s food - Rangelands
* Produces meat
* Provides 16% of the world’s food - Ocean fisheries
* Provides 7% of the world’s food
6
Q
What are some harmful enviro effects of us producing food?
A
- biodiversity loss (monocrops)
- soil changes
- water shortages
- air pollution (machinery etc)
- human health
7
Q
Which human practice has a greater harmful impact than any other human activity?
A
modern agriculture
8
Q
Biodiversity loss linked to modern agriculture:
- loss and degradation of _____from clearing grasslands and forests and draining _____
- fish killed from ____
- killing of ___ _____ to protect livestock
- loss of ______ _____ from replacing thousands of wild crop strains with a few monoculture varieties
A
- habitat, wetlands
- runoff (especially pesticides)
- wild predators
- genetic diversity
9
Q
List up to 5 negative impacts modern agriculture has on the
health of our soil
A
erosion
loss of fertility
salinization
waterlogging
desertification
10
Q
Water is negatively impacted by agriculture:
- water waste
- aquifer _____
- increased _____ and flooding from cleared cropland
- sediment pollution from _____
- pollution from ______ and ____ runoff
- __________ of lakes/ rivers from fertilizer runoff
- aquatic organisms ____ from pesticide runoff
A
- depletion
- runoff
- erosion
- pesticide and fertilizer
- overfertilization
- killed
11
Q
How does agriculture contribute to air pollution (list 3)
A
- GHG emissions from fossil fuel use (machinery etc)
- other air pollutants (eg methane) from fossil fuel use
- pollution from pesticide sprays
12
Q
Give 4 ways modern agriculture is putting human health at risk
A
- nitrates in drinking water
- pesticide residues in drinking water, food, and air
- contamination of drinking/ swimming water w/ disease/ microorganisms from livestock waste
- bacterial contamination of meat we eat
13
Q
Which 5 countries contain more than half of the total forest area in the world?
A
Canada, US, Russia, China, and Brazil
14
Q
Forests provide important ecological and economic services. List at least 3 of those uses
A
- production of wood (&non-wood!) products
- conservation/ protection
- social services
15
Q
What are the 3 major types of forests? What are these categories based on?
A
- Old growth forests
- Second growth forests
- Tree plantation/tree farm
Based on age and structure
16
Q
Old growth forests=
A
Uncut forest or regenerated forest that has not been seriously disturbed by human activities or natural disasters for at least several hundred years
17
Q
Second growth forests=
A
Stand of trees resulting from secondary ecological succession
18
Q
Tree plantation/ farm=
A
a managed stand with trees all the same age
-Harvested once they become commercially valuable
19
Q
__% of the world’s forest are old growth, __% are secondary growth, and __% are tree plantations
A
36
57
7
20
Q
deforestation=
A
The temporary or permanent removal of large expanses of forest
21
Q
Give up to 7 negative impacts of deforestation
A
- Decreased soil fertility from erosion
- Runoff of eroded soil into aquatic systems
- Premature extinction of species with specialized niches
- Loss of habitat for migratory species such as birds and butterflies
- Reginal climate change
- Release of carbon dioxide into the atmosphere
- Accelerated flooding
22
Q
What are the 3 levels of species extinction? Define each
A
- Local extinction= A species is no longer found in an area it once inhabited BUT it still found elsewhere in the world
- Ecological extinction= A species has so few members left that it can no longer play its ecological role in the biological communities where it is found
- Biological extinction= A species is no longer found anywhere in the world (this is FOREVER :( )
23
Q
How many species has Canada lost to extinction? Give an example of one or two
A
15
Dawson caribou
Labrador duck
24
Q
Threatened species=
A
A species that is likely to become endangered in the near future
Still abundant in its natural range BUT numbers are declining
25
Endangered species=
A species that could soon become extinct
Few individuals remaining in its natural range
26
Scientists estimate that __% of all species that have ever existed are now extinct. Why?
99.9%
A combination of background extinction, mass extinction, and mass depletions taking place over millions of years
27
How do biologists estimate extinction rates? Give 2 approaches
They use measurements and models
2 methods:
1. studying records documenting the rate species have become extinct
2. look at how the number of species present changes with size
28
What are 8 characteristics of species that are prone to extinction? Give an example of a species that falls under each.
1. Low reproductive rate
- Blue whale, giant panda
2. Specialized niches
- Blue whale, giant panda
3. Narrow distribution
- Elephant seal, desert pupfish
4. Feeds at high trophic level
- grizzly bear
5. Fixed migratory patterns
- whooping crane
6. Rare
- orchids
7. Commercially valuable
- elephant, rhino
8. Large territories
- grizzly bear, Florida panther
29
The current rate of extinction is ___ to ____ times the rate that is was before humans arrived
1000-10000x :(
ie 0.1%-1% rate of extinction per year
30
What was the rate of extinction before humans arrived?
1 species per 1 million (annually)
ie 0.0001% each year
31
Why is our current predicted extinction rate probably a conservative estimate?
- Rate of species loss and the extent of biodiversity loss will likely
increase during the next 100 years as the human population grows
- Rates are much higher than the global average in biodiversity
hotspots such as rain forests
- Not taking into account that many biologically diverse sites such as
coral reefs serve as colonization sites for new species
32
Percentage of species threatened with premature extinction due to human activities:
- Plants= __%
- Fish= __%
- Amphibians = __%
- Reptiles= __%
- Mammals= __%
- Birds= __%
70
34
30
28
21
12
33
Why is it important that we preserve wild species?
Because it will take at least 5 mil years for natural processes to rebuild the biodiversity we have destroyed during this century
34
Wild species benefit humans in many ways. List up to 5 instrument values and 1 intrinsic value
Instrument value:
- economic
- ecological services
- genetic info
- recreation
- ecotourism
Intrinsic Value
- existence!
35
What is the greatest threat to a species in terms of extinction?
The fragmentation, degradation, and loss of its habitat
36
What are the top 3 eliminators of terrestrial biodiversity?
1. deforestation
2. destruction of wetlands
3. plowing of grasslands
37
What is habitat fragmentation?
Occurs when a large, continuous area of habitat is reduced in area
- Divided into smaller, more scattered and isolated patches
38
Why is habitat fragmentation a problem?
Divides populations of species into smaller and more isolated groups
These groups are more vulnerable to:
* Predators
* Invasion of competitive species
* Disease
* Catastrophic events
39
Habitat fragmentation prevents species from:
(list 4)
- dispersing
- colonizing new areas
- getting enough food
- finding mates
40
Which types of species are more vulnerable to local and regional extinction due to habitat fragmentation?
- rare species
- those who require large ranges
- low reproductive capacities
- ones with specialized niches
41
* The major types of habitat disturbance threatening endangered
species are: (6)
* Agriculture (most important)
* Commercial development
* Water development
* Outdoor recreation
* Livestock grazing
* Pollution (least important)
42
Non-native species=
a species living outside its native distribution
- arrived here through human activity (directly or indirectly)
43
How do nonnative species arrive?
1. Intentional
eg. commercial/ economic purposes and pest control
- Aesthetic enjoyment
2. Unintentional
- arrive on imported goods (on ships especially)
- exotic pets escape
44
Why are nonnative species a problem?
They often have no natural controls in the new habitat to keep the population in check (no natural predators/ competitors etc)
- can reduce the population of native species & cause ecological disruptions
45
Give an example of a nonnative species that added pressure on native threatened/ endangered species
zebra mussels
46
List up to 7 characteristics of successful invader species
* R-selected species
* High reproductive rate
* Short generation time
* Pioneer species
* Long-lived
* High dispersal rate
* Release growth-inhibiting chemicals into the soil
47
What are the characteristics of ecosystems vulnerable to invader
species?
* Similar climate to the natural habitat of the invader
* Absence of predators of the invader
* Early successional systems
* Low diversity of native species
* Absence of fire
* Disturbed by human activities
48
How can we reduce threats from nonnative species?
Prevention!
- control routes that invasive species arrive via
- inspect good for these species
- ban the transfer of these species b/w countries
Prevention is important because once a nonnative species is established it's nearly impossible to remove them
49
Why are poaching and wildlife smuggling so common?
- many at risk species are valued for their parts
- as their # declines= more valuable= more likely to be poached
Big extinction threat :(
50
How much money could a poacher make from a panda pelt or Bengal tiger fur?
$100,000
51
T/F
Most poachers are caught, even though the money they make outweighs the risk of being caught
false
most are not caught :(
money definitely does outweigh the small risk of being caught
52
Predator control=
Is this an extinction threat?
the removal of a species that competes with humans or causes inconveniences
eg. prairie dogs
YES!
53
Another extinction threat is the market of exotic pets and decorative plants. How?
- There is a trade market (often illegal) for these exotic/ rare species
- people sell them for lots of money
- lots die in transit
- removing them from their habitat endangers other species that depend on them
54
How does climate change pose an extinction risk to some species?
humans have accelerated climate change, so species don't have time to adapt or move to a more suitable enviro
= lots of them will just die :(
55
In Canada, __% of our habitats could be altered by the end of the century, resulting in a __% loss in species
45
20
56
How does pollution pose an extinction risk to some species?
Exposure
- toxic/ carcinogenic/ gender changing
Bioaccumulation/ biomagnification
57
Summarize the basic causes of premature species extinction (there are 4)
* Population growth
* Rising resource use
* No environmental accounting
* Poverty
58
Summarize the secondary causes of premature species extinction (up to 9)
* Habitat loss
* Habitat degradation and fragmentation
* Introducing nonnative species
* Overfishing
* Climate change
* Predator and pest control
* Pollution
* Commercial hunting and poaching
* Sale of exotic pets and decorative plants
59
Earth's climate is determined by average ____ and ______.
Is this fixed?
temp and precipitation
Not fixed, not new or unusual
60
T/F
1. the average temp has changed gradually in the past (100s to millions of yrs)
2. in the past 900,000 yrs, the earth has undergone prolonged periods of cooling and warming
true
true
61
A fairly stable climate during the past ___ years allowed humans to flourish
10,000
62
Temperatures began to rise with the start of the Industrial Revolution
Why?
Most of the increase has happened since ___
* Clearing forests
* Burning fossil fuels
1975
63
Explain how ice core drilling helps us study climate change
analyze air bubbles in different sections of cores. Get info about:
* Past tropospheric composition
* Temperature trends
* Greenhouse gas compositions
* Solar activity
* Snowfall
* Forest fire frequency
64
What do sediment cores from the bottom of lakes/ ponds tell us about climate change?
Gives info about
* Trends and types of organisms
* Pollen
* Fossils
* Plants
65
Collecting air samples is a method used to study climate change. What info that does that give?
Chemical composition of the atmosphere
66
Explain the Earth's greenhouse effect
1. sunlight penetrates the lower atmosphere and warms earth sfc
2. sfc absorbs lots of incoming radiation & degrades it to longwave infrared radiation (IR), which rises into lower atmosphere. Some of this IR escapes into space as heat & some is absorbed by molecules of GHG and emitted as even longer wavelength IR, which warms lower atmosphere
3. as GHG concentrations rise, their molecules absorb and emit more infrared radiation, adding more heat to lower atmosphere
67
What role does the natural greenhouse effect play
on Earth’s temperature and climate?
* Sunlight warms the Earth’s atmosphere and surface
* Some sunlight is radiated back towards space
--> Clouds, water vapor, carbon dioxide, and other gases absorb the radiation
--> The clouds and gases radiate longer wave length radiation in all directions
68
What is earth's natural cooling process?
large amounts of heat are absorbed by evaporation
- water molecules rise and condense to form water droplets
- release their heat higher in the atmosphere
69
What are the 2 major GHG and what controls them?
1. Water vapor
- hydrologic cycle
2. Carbon dioxide
- carbon cycle
70
How long do the following GHG stay in the troposphere?
- CO2
- CFCs
- Methane
- 100-200 yrs
- 11-20yrs
- 12-18yrs
71
What is the difference between global warming and global climate change?
global warming= temp increases in the atmosphere, which can cause climate change
global climate change= changes in any aspect of climate (including temp)--> can be cooling or warming
72
How have human activities affected tropospheric concentrations of GHG?
- [GHG] has risen sharply
- CO2>440ppm, which is higher than it has been in the past 400,000yrs
we are emitting GHG faster than natural processes can remove them
73
Why are we seeing this sharp increase in GHG?
- Increase in the use of fossil fuels since the 1950’s
- deforestation/ land clearing releases CO2 and nitrous oxide
- Livestock: release methane from digestive process
- rice paddies: inorganic fertilizers release nitrous oxide
74
Which country is the largest GHG emitter currently?
China
It used to be the US
75
Canada emits __ megatons of GHG each year, which is less than __% of global emissions
However, per capita it is ___ tonnes/ person/ year, which is __x the global average (mostly from wasteful energy use)
700
2%
20.7
4x
76
The troposphere is very likely warming. Why?
1. Past three decades were warmer
* Each warmer than the previous
* Warmest 30 year period of the past 800 years
2. Average temperature has risen almost 1°C
* Between 1880 and 2012
* Majority of the increase since 1980
3. Oceans have increased temperatures
* Top 75m of oceans have become warmer globally
4. Glaciers and floating ice are melting
* Arctic ice shrinking every year
5. Average sea level rising by 7.5in
77
Surface temp is projected to rise by as much as __C.
The level of sfc warming will be determined primarily by ____ ___ _____
many impacts associated with climate change will continue even if emissions are ___
4.8C
carbon dioxide emissions
stopped
78
How could oceans potentially help moderate earth's temp?
remove 29% of the excess CO2
- absorb heat from the atmosphere and slowly transfer to the deep ocean
HOWEVER this would likely have negative impacts on the ocean itself
79
How long does it take for the absorbed hear and CO2 to be transferred to the deep ocean?
How long before it is released back into the atmosphere?
We don't know either of these answers, which might be problematic
80
How might stored carbon dioxide affect the ocean's water chemistry?
more CO2 absorbed= more acidic
- Calcium carbonate becomes less available for shells and skeletons
- impacts larval development
- impacts fish respiration
81
How might changes in cloud cover affect the troposphere's temperature?
- Warmer temperatures increase evaporation
- Increased evaporation creates more clouds
- Additional clouds can:
1. Absorb and release some of the heat
2. Reflect more sunlight
82
How might changes in cloud cover affect the troposphere's temperature?
The effect depends on the type, ____, and ____ of the clouds. For example:
type, coverage, altitude
- thick, continuous clouds at low altitudes can decrease surface warming
- thin, discontinuous clouds at high altitudes can increase sfc warming
83
How might outdoor air pollution affect the troposphere’s temperature?
* Most aerosols produced from fossil fuel combustion reflect incoming
light
--> Cools the atmosphere
* Sulphate particles act as a nuclei for cloud formation
--> Cools the atmosphere
84
Why is the effect of outdoor air pollution temporary?
* Aerosols and particles fall back to Earth or are washed out of the atmosphere
* While carbon dioxide and other greenhouse gases remain in the atmosphere for longer
* Aerosols inputs are also being reduced around the world
85
T/F
increased CO2 levels can increase the photosynthesis rate, which could slow global warming
true!
b/c it increases the removal of CO2 from the atmosphere
86
Why would the effect of increased photosynthesis be temporary?
* As plants mature they take up less carbon dioxide
* Stored carbon dioxide would be returned to the atmosphere when the plants die and
decompose
* Insects breed and grow more rapidly in warmer temperatures
--> Offset plan
87
How might a warmer troposphere affect methane emissions?
increased release of methane could accelerate warming further.
2 sources:
- bogs and wetlands
- methane hydrates
88
T/F
There are both potential benefits and harmful effects of a warmer world
true
depends on location & how quickly temp changes
89
What locations will be impacted the most by warming?
poor nations in the tropics
90
With a warming world, what changes might we see in agriculture?
- shifts in growing areas
- changes in yields
- increased irrigation demand
- more pests, crop diseases
91
With a warming world, what changes might we see in water resources?
- changes in water supply
- decreased water quality
- more drought/ floods
- snowpack reduction
- melting of mtn glaciers
92
With a warming world, what changes might we see in forests?
Changes in forest composition and locations
* Disappearance of some forests, especially at high elevations
- more fires
- loss of wildlife habitat + species
93
With a warming world, what changes might we see in biodiversity?
- extinction of some plants and animals
- loss of habitats
- disruption of aquatic life
94
With a warming world, what changes might we see in sea level & coastal areas?
- Rising sea levels
- Flooding of low lying islands and coastal cities
* Flooding of coastal estuaries, wetlands and coral reefs
* Beach erosion
* Disruption of coastal fisheries
* Contamination of coastal aquifers with salt water
95
With a warming world, what changes might we see in weather extremes?
- prolonged heat waves/ droughts
- increased flooding (more frequent/ intense rainfall in areas)
96
With a warming world, what changes might we see in human population?
- more deaths from heat/ disruption of food supplies
- more environmental refugees
- increased migration
97
With a warming world, what changes might we see in human health
* Decreased deaths from cold weather
* Increased deaths from heat and disease
* Disruption of food and water supplies
* Spread of tropical diseases to temperate areas
* Increased respiratory disease and pollen allergies
* Increased water pollution from coastal flooding
* Increased formation of photochemical smog
98
How might a warmer troposphere affect BC?
high sea levels= flooding/ coastal erosion
less hydroelectricity and fishery success b/c of reduced water water flow
earlier melting of snow packs= less water to fight fires
99
How might a warmer troposphere affect the prairies?
* Longer growing season
* More droughts increasing the need for irrigation
* Lakes and wetlands would disappear
* Loss of prairie water fowl
100
How might a warmer troposphere affect the arctic/ subarctic?
* Changes in ice cover and permafrost characteristics
* Impact people and wildlife
101
How might a warmer troposphere affect the boreal forest?
* Longer growing season
* Shift north over time
* Increase in fires
* Increase in insect pests
* Threaten wildlife
102
How might a warmer troposphere affect the great lakes?
* More heat waves
* More smog and air quality problems
* Increase in health problems
* Decrease in lake water levels
* Negatively impacting shipping and hydroelectricity
* Greater need for irrigation
* Increase in severe weather events
103
How might a warmer troposphere affect eastern canada?
* Higher sea levels
* Coastal flooding and erosion
* Loss of wetlands
* Increase in insect pests
* Changes in fish migrations
* Negatively impact fisheries
104
