3.1.1.4 Climate Change Flashcards
1
Q
What is climate change the result of?
A
climate change is the result of natural and human factors and has a range of effects
2
Q
How old is the Earth believed to be?
A
The Earth is believed to be 4.55 billion years old and so studying the Earth has led us to devise a geological timescale that divides Earth’s history into a series of eras, periods and epochs
3
Q
What is the quaternary period?
A
- The period of time that spans from 2.6 million years ago to the present day is called the Quaternary Period
- This period marks a time when there was a global drop in temperature and the most recent ice age began
- It is thought that there have been 5 ice ages in Earth’s history
4
Q
What is the Holocene?
A
- The Holocene is the current geological epoch. It began approximately 11,650 calendar years before present, after the last glacial period, which concluded with the Holocene glacial retreat
- The Holocene and the preceding Pleistocene together form the Quaternary period
5
Q
What has the Holocene witnessed?
A
- Holocene has witnessed all of humanity’s recorded history and the rise and fall of all its civilisations
- Humanity has greatly influenced the Holocene environment; while all organisms influence their environments to some degree, few have ever changed the globe as much, or as fast, as our species is doing
6
Q
How have global temperatures changed since 1800 and 1900?
A
- 1 degrees C since 1800 and about 0.7 degrees C during last 100 yrs
- since 197- rate of increase has been roughly 0.17 degrees C per decade
7
Q
Evidence for climate change:
A
- rising sea levels
- shrinking glaciers and melting ice
- seasonal changes
- ice cores
- ocean sediments
8
Q
By how much have the sea levels changed?
A
- according to IPCC (2019) global mean sea level is rising and acceleration
- on average between 1993 and 2015 global sea levels rose by 3.2mm per year compared with 1.4mm between 1901 and 1990
9
Q
By how much have sea lives risen in the past 100 years?
A
Intergovernmental Panel on Climate Change (IPCC), the average global sea level has risen between 10 and 20 cm in the past 100 years
10
Q
What are the 2 main reasons for sea levels rising?
A
- melting of freshwater glaciers and ice sheets, adding water to the oceans
- thermal expansion (increase in volume of seawater) cause by an increase in water temperature
11
Q
How much ice have we been losing from Antarctica per year according to NASA data?
A
NASA data shows that since 2002 we have been losing an average of 134bn tonnes of ice from Antarctica each year
12
Q
By when may glaciers have completely disappeared?
A
Glaciers may have completely disappeared by 2035
13
Q
What is the % reduction in Arctic sea ice since 1975?
A
65 % reduction in Arctic Sea ice since the 1975
14
Q
How have the timing of natural seasonal events been changing?
A
studies suggest that the timing of natural seasonal activities such as tree flowing and bird migration is advancing by up to 2 days per decade
15
Q
How has bird nesting changed in Finland?
A
- a study in Finland (from 1975 to 2012) discovered that birds are nesting earlier, increasing competitions for food supply
- these changes have been linked to global warming
16
Q
What does a study of bird nesting in mid-1990s show?
A
a study of bird nesting in the mid-1990s discovered that 65 species nested an average of 9 days earlier than the 1970s
17
Q
How are Antarctica ice cores used to act as evidence for climate change?
A
- They are known as proxy data, data from before official records were kept
- The layers of Antarctic Snow remain untouched by humans and as they build up they present a picture of the climate of the times
- They use oxygen isotopes within the ice to work out what the temperature would have been like
- Additionally, when the ice melts methane and CO2 are released which can be compared to present levels to see the differences between climate then and now
- More accurate than ocean sediment
18
Q
When did reliable weather records begin?
A
1910
19
Q
How far back can ice cores be used to see the atmosphere?
A
800,000 years
20
Q
How can ocean sediment act as evidence for climate change?
A
can use fossil evidence that is collected within the sediments to determine what the climate and conditions would have been like previously such as past surface water temperatures, levels of oxygen and nutrients
21
Q
Eccentricity:
A
describes the path of the Earth as it orbits the Sun
22
Q
How may eccentricity be a cause of climate change?
A
- Earth’s orbit not fixed - it changes from being almost circular to being mildly elliptical
- a complete cycle from circular to elliptical and back to circular again occurs about every 100,000 years
23
Q
What does the Earth spin on and what does this cause?
A
the Earth spins on its axis, causing night and day
24
Q
How might axial tilt be a cause of climate change?
A
- the Earth’s axis is currently tilted at an angle of 23.5 degrees
- however, over period of approx. 410,000 years the tilt of the Earth’s axis moves back and forth between 2 extremes - 21.5 degrees and 24.5 degrees
25
What is precession?
precession describes a natural “wobble” rather like a spinning top
26
How may precession be a cause of climate change?
- a complete wobble cycle takes about 26,000 years
- Earth’s wobble accounts for certain regions of the world e.g. northern Norway experiencing very long days and very long nights at certain times of the year
27
How may solar output be a cause of climate change?
scientists identified cyclical changes in solar energy output linked to the presence of sunspots
28
What is a sunspot and how doe the number of sunspots change?
- sunspot is a dark patch on surface of Sun that appears from time to time
- number of sunspots increases from a minimum to a maximum and then back to a minimum over a period of about 11 years
- 11 year period is called the sunspot cycle
29
How may maximum sunspot output affect the climate?
- when sunspot output is at a maximum the Sun gives off more heat
- large explosions occur on the surface of the Sun resulting in solar flares
30
How may minimum sunspot output affect the climate?
- when sunspot output is at a minimum the solar output is reduced
- can lead to lower temps on Earth
31
When has low sunspot output affected the climate on earth?
- very few sunspots observed between years of 1645 and 1815
- coincided with coldest period during so-called ‘Little Ice Age’ when Europe experienced a much colder climate with severe winters
32
What do violent volcanic eruptions do?
violent volcanic eruptions blast huge quantities of ash, gases (such as carbon dioxide) and liquids into the atmosphere
33
How may volcanic activity be a cause of climate change?
- fine particles of ash can block out the Sun, leading to a short-term reduction in surface temperatures called a ‘volcanic winter’
- in the cold lower atmosphere, sulphur dioxide is converted to sulphuric acid by the Sun’s rays reacting with water vapour
- these fine aerosols act like tiny mirrors reflecting radiation from Sun
- can lead to longer term cooling lasting up to 3 yrs
34
When did Mount Pinatubo erupt?
15th June 1991
35
How large was Mount Pinatubo’s last eruption?
2nd largest terrestrial eruption of 20th C
36
How expected was Mount Pinatubo’s eruption in 1991?
- Pinatubo had not erupted for 500 years prior to its eruption in 1991
- Scientists had thought the dormant volcano was extinct and would never erupt agai
- Instead, it was a sleeping giant with magma quietly collecting 20 miles beneath the volcano
37
When and how did Mount Pinatubo begin awakening?
- The volcano began awakening in 1990 when a 7.8 earthquake shook the area
- The following spring thousands of earthquakes and tons of sulphur dioxide were emitted by the volcano warning scientists and people living near the volcano that an eruption was coming
38
What did Mount Pinatubo eject when it erupted?
- ejected vast amounts of ash and gas high into the atmosphere, so high that the volcano's plume penetrated into the stratosphere.
- over the course of several eruptions a massive 10 cubic km of material was ejected
39
How much sulphur dioxide did Mount Pinatubo eject and what affect did this have?
- Pinatubo also injected about 15 million tons of sulphur dioxide into the stratosphere
- Sulphur dioxide reacted with water to form a layer of aerosol particles made up of sulfuric acid droplets
- Over the course of the next two years, strong stratospheric winds spread these aerosol particles around the globe
40
How was the world’s temperature impacted by Mount Pinatubo’s eruption?
Data collected following the eruption showed that the mean world temperatures decreased by about 1°C over the two years following the eruption
41
Natural causes of climate change:
- Eccentricity
- Axial tilt
- Precession
- Solar output
- Volcanic activity
42
Human causes of climate change:
- Fossil fuels
- Agriculture
- Deforestation
43
Greenhouse gas effect diagram:
44
What have scientists identified there has been since the 1950s?
unprecedented rise in average global temperatures → associated with increase in carbon emissions
45
What is the greenhouse gas effect?
- the atmosphere allows most of the heat from the Sun in the form of short-wave radiation to pass straight through it to warm the surface of the Earth
- the warmed gives off heat and emits long-wave radiation
- whilst some heat escapes into spaces some gases such as CO2, CH4 and N2O are able to absorb it
- these gases are called GHGs - the trap heat and keep the Earth warm
46
What is the enhance greenhouse gas effect?
- human activity increase conc of GHGs esp. CO2 (77% of all GHG emissions) in the atmosphere
- increased the amount of trapped heat → enhancing greenhouse effect → leading to global warming
47
Fossil fuels:
a fuel formed by natural processes e.g. decomposition of buried dead organisms like plants
48
How do fossil fuels increase GHG emissions?
when used to create energy in form of heat, CO2 and other GHGs are emitted
49
What % of GHG emissions does agriculture emit?
- 30% of all GHG emissions
- 40% of all methane emissions
50
How does agriculture increase CO2 emissions?
- land use change (land drainage and deforestation) + soil disturbance (ploughing releases carbon in soil)
- E used for heating and transportation on the farm and in distribution
51
How does agriculture increase methane emissions?
- livestock digestion releases methane (mostly through burping) → average ruminant produces 250-500 litres of methane a day
- anaerobic decomposition in paddy rice cultivation accounts for 5-20% of total methane emissions from human sources
52
How does agriculture increase nitrous oxide emissions?
- agriculture emits 75% of all nitrous oxide, mostly from manure and nitrogen-rich fertilisers
- highly managed grasslands produce large volumes due to fertiliser use and soil disturbance
53
Deforestation:
cutting down or burning trees usually to clear land for farming, settlement or industry
54
How does deforestation increase CO2 emissions?
carbon stored during photosynthesis (when green plants convert light energy to chemical energy is re-released into the atmosphere as carbon dioxide
55
What % of annual GHG emissions does deforestation account for?
accounts for approx. 20% of annual global GHG emissions
56
What % of tree cover has Indonesia lost?
since 2000 Indonesia lost almost 10% of its tree cover - mostly for commercial production of palm oil
57
What is the main reason for recent increase in emissions?
main reason for recent increase in emissions is growing demand for, and trade in, agricultural and forestry commodities, mainly palm oil, soy, cattle and timber products inc. paper
58
What is 70% of deforestation in the Amazon RF due to?
70% of deforestation in the Amazon RF is to create grazing land for commercial livestock
59
What are some global effects of climate change?
- many of world’s glaciers and ice caps are shrinking
- Arctic sea ice is less extensive than in the past, affecting wildlife such as polar bears - may provide opportunities for ships to use the North West Passage in the future
- low-lying islands such as Maldives and Tuvalu under threat of sea-level rise
60
By how much are global sea levels predicted to rise by 2100?
- IPCC predicts that global mean sea level will rise between 0.48 and 0.84m by 2100
- may even rise by as much 1.1m
61
How may climate change impact people living in coastal areas?
100s of millions of people around the world in low-lying areas along the coast —> could cause flooding as sea level increases
62
How may climate change environmentally impact coastal areas?
rising sea levels will erode beaches + stronger storms caused by warmer beaches —> completely wipe out certain beaches and islands
63
How may climate change impact coastal cities in coastal areas?
- coastal cities e.g. Miami, NYC, Venice etc. could flood more often/severely if sea levels continue to rise
- if that happens many will lose homes + businesses
64
What do forests provide homes for and what do they protect?
- forests provide homes for many kinds of plants and animals
- protect water quality, offer opportunities for recreation, and provide people with wood
65
How may climate change cause an increase in frequency of wildfires?
- wildfires already common in forests and grasslands of the western US
- as Earth gets warms, droughts increase, wildfires expected to occur more often and be more destructive
- extremely dry conditions resulting from droughts allow fires to start more easily, spread faster, and burn longer
66
How could an increase in temperature affect wildfires?
if Earth gets just 3.6 degrees F warmer, can expect wildfires in western US to burn 4x more land than they do now
67
How may wildfires impact people?
fires don’t just burn landscape - also threaten people’s homes and lives
68
What do crops need to grow?
crops that we grow for food need specific conditions to thrive inc. right temp and enough water
69
How may climate change positively impact agriculture?
- the northern parts of US have generally cool temps, so warmer weather could help certain crops grow
- in southern areas where temps are already hot, even more heat could hurt crop growth
70
How may climate increase crop losses?
- climate change could make it too hot to grow certain crops, and droughts caused by climate change could reduce amount of water available for irrigation
- climate change also likely to cause stronger storms and more floods → can damage crops
- higher temps and changing rainfall patterns could help some kinds of weeds and pests to spread to new areas
71
How could an increase in temps impact corn production in the UK?
if globals temp rises an additional 3.6. degrees F US corn production is expected to decrease by 10-30%
72
How might climate change impact the amount of energy required by people?
- as temps rise more people will need to keep cool using AC which uses a lot of electricity
- however, some people might need less E to heat buildings in Winter as it may not get as cold as it used to be
73
How could climate change impact certain types of electricity like hydropower?
- as climate change causes precipitation patterns to shift, some areas that currently have plenty of water to make hydropower, such as northern California, might not have enough water in the future
- without enough water to produce electricity these areas could experience power shortages and blackouts
- they mights have to use other E sources to make more of the electricity they need and if these sources are fossil fuels like coal, oil, or natural gas, more GHGs will be added to the atmosphere
74
How may climate change impact recreational activities?
- heat waves, droughts, coastline damage, warmer temps could affect people’s jobs, recreational activities and hobbies
- e.g. in areas that usually experience cold winters, warmer temps could reduce opportunities for skiing, ice fishing and other winter sports
75
How may climate change impact beaches?
- rising sea levels will mean less space at the beach
- a combination of stronger storms and sea level rises could increase the rate of erosion along the coast and some beaches could disappear all together
- reduces number of recreational activities available on the beach
76
How may climate change impact water supplies?
rising temps + changing precipitation patterns + increasing droughts will affect amount of water in lakes, rivers and streams as well as the amount of water that seeps into the ground to replenish ground water
77
How has climate change impacted public water supplies in south-eastern US?
- in 2007 a major drought hit south-eastern US
- Lake Lanier which is main source of drinking water for the Atlanta area, was reduced to record-low water levels
- people had to use less water in their homes and businesses and make other changes e.g. not watering their lawns
78
How may climate change impact lakes, rivers and streams?
- many places rely on snowmelt to fill lakes, rivers and streams that help keep drinking water reservoirs full and provide water to irrigate crops
- e.g. many parts of western US depend on water from the Colorado River which is fed by melting snowpack in the Rocky Mountains
- less snowpack and earlier snowmelt will reduce the amount of water flowing into the Colorado and other rivers
79
How may climate change cause temperature-related illnesses?
- heatwaves for infants, young children, the elderly and people who are already sick can be esp. dangerous
- extreme heat can cause illnesses such as heat cramps, heat strokes and even death
80
How many deaths were caused by the 2003 heatwave in Europe?
50,000 deaths caused by the 2003 heatwave in Europe
81
How many deaths did the 1995 heatwave cause in Chicago?
1995 heatwave causes more than 600 deaths in Chicago?
82
How many deaths do heatwaves in the US cause?
heat waves cause more deaths in the US every year than hurricanes, tornados, floods and earthquakes combined
83
How may climate change cause illnesses to do with air pollution?
- certain kinds of air pollutants like ozone can make asthma and other long conditions
- ozone found high in atmosphere is called ‘good ozone’ because it protects life on Earth from the Sun’s harmful UV rays
- ozone can be found close to the Earth where it is considered to be ‘bad ozone’ as it is the main ingredient of smog and is harmful for people to breath
84
How is bad ozone created?
- bad ozone created from pollutants that go through chemical reactions in the atmosphere
- climate change likely to increase amount of bad ozone in the air because more ozone is created when the temperature is warm
