Enquiry Question 3: How are the water and carbon cycle linked to the global system? Flashcards

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1
Q

Annual change in forest area, 1990-2015

A
  • South America has seen a lot of deforestation, specifically Brazil, which has a net loss of >500
  • Africa has a net loss of 250-50
  • Indonesia has a net loss of 500-250
  • An area which hasn’t seen much loss (50-250 net gain) is Russia
  • Europe has seen a lot of net gain, however a majority of it is small
  • India and America have the highest net gains at 250-500
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2
Q

Tropical forests have lost ___ of their area since the 1960s

A

50%

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3
Q

What percentage of temperate forests had been deforested by the 19th century?

A

90%

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4
Q

What fraction of carbon dioxide does the terrestrial biosphere sequester/store annually?

A

1/4

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5
Q

How can land conversion affect the carbon and water stores?

A

Land conversion could change the land from a natural ecosystem to an alternative use, which usually reduces carbon and water stores as well as soil health

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6
Q

Deforestation - impacts on the water cycle

A
  • Infiltration is decreased
  • Flood peaks are higher and the lag time is shorter
  • Increased discharge leads to flooding
  • More eroded material is carried in the river, bot has bed load and as silt and clay in suspension
  • Annual rainfall is reduced and the seasonality of rainfall increases
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7
Q

Deforestation - impacts on soil health

A
  • Raindrop impact washes finer particles of clay and humus away
  • Coarser and heavier sands are left behind
  • Carbon dioxide is released from decaying woody material
  • Biomass is lost, due to reduced plant growth/photosynthesis
  • Rapid soil erosion leads to a loss of nutrients
  • Increased leaching (the loss of nutrients from the soil by infiltration) means that minerals are lost
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8
Q

Deforestation - impacts on the atmosphere

A
  • Turbulence is increased as the heated ground induces convectional air currents
  • Oxygen content is reduced and transpiration rates are lower
  • Reduced shading leads to more direct sunlight reaching the forest floor
  • Reduced evapotranspiration makes it less humid
  • The air is dryer
  • Evapotranspiration rates from the resultant grasslands are about one-third that of the tropical rainforests
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9
Q

Deforestation - impacts on the biosphere

A
  • Evapotranspiration from vegetation is reduced
  • Less absorption of carbon dioxide means a reduced carbon store
  • Species diversity is reduced (e.g. less-resilient forest plants die off)
  • Ecosystem services are reduced
  • The decrease in habitats means that fewer animal species survive
  • Biomass is lost , because of reduced plant growth/photosynthesis
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10
Q

Causes of deforestation (why people do it)

A
  • 50% of all deforestation is for soy, palm oil, beef and paper production
  • Dams and reservoirs
  • Infrastructure
  • Open cast mining for rare materials
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11
Q

Methods of deforestation

A
  • Clear cutting - used for loggings, removes all primary forest
  • Slash-and-burn - used for agriculture - trees are cut and set alight. Ash from the trees provides nutrients for the soil
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12
Q

What percentage of forests in Madagascar has been deforested?

A

90%

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13
Q

Who is to blame for the deforestation happening in Madagascar?

A

Private industrial companies

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14
Q

What do the local people in Madagascar use the forest for?

A
  • Agriculture (mango growing)
  • Medicines
  • Charcoal (cooking, domestic heating)
  • Infrastructure (village housing) - due to increased populations
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15
Q

Why are the forests in Madagascar so vulnerable?

A
  • Increasing population
  • Lack of government support
  • No international aid
  • Growing international demand for tropical hardwood
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16
Q

What are the solutions to the deforestation in Madagascar?

A

External workers to work locally to provide an alternative solution for the local population

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17
Q

What are the negative impacts if the rate of deforestation continues?

A
  • No remaining forest

- Long term droughts and extending monsoon seasons

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18
Q

Afforestation

A
  • Planting trees on land that hasn’t had forest, or has been without forest, for a long time
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19
Q

Reforestation

A

Planting trees in places with recent tree cover, replacing lost primary forests

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20
Q

Afforestation - impacts on carbon cycle

A
  • Monocultures of commercial trees such as in palm oil plantations often store less carbon
  • Biodiversity may be impacted as a result of habitat changes
  • Monocultures tend to be more disease prone - has a negative effect on biodiversity
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21
Q

Afforestation - impacts on water cycle

A
  • Monocultures tend to use more water leading to less infiltration and groundwater rates
  • Decreased raindrop erosion
  • Evapotranspiration rates may alter surrounding downwind ecosystems
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22
Q

Monoculture

A

The agricultural practice of producing or growing a single crop, plant, or livestock species, variety, or breed in a field or farming system at a time

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23
Q

Example of afforestation

A

China’s Three-North Shelterbelt project - a 4500km green wall of trees designed to reduce desertification

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24
Q

Grassland conversion in the USA

A
  • 2007-2015 = biofuel ‘rush’ swept across the Prairies
  • During this, farmers were encouraged to grow corn, soya, canola, and sugar cane as part of the US Environmental Protection Agency’s Renewable Fuel Standard Policy
  • By 2013, the price of corn trebled
  • Over 5.5 million hectares of natural grassland disappeared across the Prairies (matches the deforestation rates across Brazil, Malaysia and Indonesia)
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25
Q

US Environmental Protection Agency’s Renewable Fuel Standard Policy aims

A
  • Increase the amount of ethanol being used in petrol
  • Boost the economies of rural US states
  • Reduce US dependence on overseas oil transport
  • Reduce carbon dioxide emissions from transport
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26
Q

Benefits of natural grasslands

A
  • Trap moisture and floodwater
  • Absorb toxins from the soil, maintaining their health
  • Providing cover for dry soils - preventing soil erosion
  • Maintain natural habitats
  • Acts as a carbon sink and a terrestrial carbon store
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27
Q

Drawbacks of grassland conversion

A
  • Soils release carbon dioxide when grasslands are initially removed and through annual ploughing
  • Biofuel crops need carbon-based nitrogen fertiliser and chemical pesticides, so they produce a net increase in carbon dioxide emissions
  • Biofuels consume a lot of water, impacting on local aquifers for irrigation
  • Cultivated soils are liable to erosion by surface runoff and wind
  • Natural habitats are lost
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28
Q

Drought

A

An extended period of deficient rainfall relative to the statistical average of that region measured over a long period of time

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29
Q

Palm oil

A
  • The most commonly produced vegetable oil
  • 68 million tonnes are produced each year
  • Tropical climate is perfect for maximising crop yields
  • A huge driver for deforestation
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30
Q

How many land conflicts had been linked to palm oil in 2016?

A

700 - indigenous people driven out of areas they had inhabited for generations

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31
Q

How many people depend on forests? What percentage of these are the poorest in societies?

A

1.6 million people, 90%

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32
Q

Forests are the source of what percentage of global biodiversity?

A

80%

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33
Q

Forests provide what percentage of the global economy income?

A

1.1%

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34
Q

Forests provide how many ‘formal’ and ‘informal’ jobs?

A

13.2 million ‘formal’ jobs and 41 million ‘informal’ jobs

35
Q

Between 1990 and 2015, how much had the rate of net global deforestation been slowed down by? (%)

A

50%

36
Q

Between 1990 and 2015, how much had total forest carbon emissions decreased by? (%)

A

25%

37
Q

Fuel wood source is used by what fraction of people globally for cooking and boiling water, etc.?

A

1/3

38
Q

Kuznets curve

A

A model that suggests that societies reach a tipping point where exploitation changes more towards protection

39
Q

Forest recovery globally

A
  • 13% of forests (534 million hectares) are now classed as ‘conserved’
  • Brazil and the USA have the largest National Parks and Forest Reserves
  • Carbon sequestration projects are increasing
  • Temperate forest area (mainly in developed countries) has increased, although normal tropical rainforests (mainly in developing countries) has decreased
  • Brazil has halved its deforestation rate since 2000 but continues to lose forests
40
Q

Forest recovery in the UK

A
  • Forest cover in the UK has dropped from 80% to 10% over the centuries
  • The Forestry Commission has planted fast growing conifers like Sitka spruce
  • Forest cover has increased by 25% between 1870-1947 and by 50% between 1948-1995
  • By 2016, 13% of the UK was forested (increased indigenous species)
41
Q

Forest protection - Indonesia

A
  • May 2011 - Indonesia’s president declared a ‘forest moratorium’ - aimed at trying to reduce deforestation
  • They received $1 billion funding from the UN and Norwegian government
  • The moratorium stopped new lands getting forest clearance permits
  • BY 2013, emissions had fallen by 1-2.5%, however illegal logging is still an issue
  • In 2015, the moratorium was extended to help Indonesia further reduce its carbon dioxide emissions by 26% by 2020
42
Q

Impacts of rising temperatures

A
  • Precipitation patterns - existing ones will get stronger because warm air traps more water
  • River regimes - ‘the annual variation in discharge or flow, at a particular point’, the character of the regime is influenced by the climate
  • Water stores - cryosphere loses mass as ice sheets and glaciers melt, arctic temperatures have risen twice as fast as global averages in the past 20 years - implications for oceans currents, air circulation, sea level rise and flooding
43
Q

Arctic - impacts of rising temperatures

A
  • Over the last 20 years, the ice sheets in the Antarctic and Greenland have been losing mass and the Arctic sea ice and northern hemisphere snow cover have continued to decrease in extent and thickness
  • The Arctic acts as an early warning system, acting as a barometer of the environmental impacts resulting from fossil fuel use
  • In the past few decades, average Arctic temperatures have risen twice as fast as global averages: 3-4 degrees in Alaska and north-west Canada. This could soon increase another 4-5 degrees over land, and 7 degrees over ocean
44
Q

Yukon - impacts of rising temperatures

A
  • Yukon - far northwest of Canada, a significant part of it lies in the Arctic circle
  • Increasing temperatures have led to the following:
    • Increased evaporation and atmospheric water vapour
    • Across Yukon, winter precipitation increased between 1950 and 1998, however a greater proportion fell as rain in spring and less as snow
    • Snowmelt begins earlier, decreased snow cover - alters river regimes
    • Between 1958-2008, the total ice area shrank by 22% and, as glaciers recede, streamflow is decreasing, despite an increase in meltwater
    • Thawing of permafrost - could increase the amount of groundwater
    • Since 2000, inflows to the Yukon river have increased by 39% due to increasing temperature and precipitation
45
Q

Rising temperatures - effects on the water cycle

A
  • Rising local temperatures - increased evaporation
  • Warm water flowing into the Arctic from the Pacific and Atlantic
  • Shrinkage of sea ice; the Arctic ice cap averages only 3m thick and melting is increasing faster than anticipated
  • Run-off of fresh, cold water will alter marine ecosystems and food chains dependent on saline waters; predicted to affect areas outside the Arctic ocean by 2100
  • Funneling of more cold water into the oceanic conveyor belt
46
Q

Rising temperatures - effects on the carbon cycle

A
  • Increased or new emissions of: CH₄ (methane) from destabilisation of wetlands and sea floor deposits containing methane hydrate, stored for thousands of years
  • Increased or new emissions of: carbon dioxide from increased forest fires as boreal forests dry out; they may also absorb carbon dioxide and methane from the atmosphere
  • Increased or new emissions of mainly carbon dioxide and methane from thawing permafrost
47
Q

How many times more powerful is methane compared to carbon dioxide?

A

24x more

48
Q

Mangroves

A
  • Found along tropical and sub-tropical coasts of Africa, Australia, Asia and the Americas
  • They sequester almost 1.5 metric tonnes of carbon per hectare, per year
  • Their soils consist of thick organic layers of litter, humus and peat, which contain high levels of carbon dioxide (over 10%)
  • These soils are anaerobic as they are submerged by high tides twice a day, meaning that bacteria and microbes cannot survive, so decomposition of plant matter is slow - little carbon is released back into the atmosphere
49
Q

Benefits of mangroves

A
  • They stabilise the coastline against erosion
  • They provide protection and shelter against extreme weather (e.g. storms, winds and floods) and tsunamis, by absorbing and dispersing surges
  • They provide nurseries for coastal fish away from predators
50
Q

Human activity on mangroves

A
  • We’re draining and clearing them for tourism, shrimp farming and aquaculture - this has accounted for over 25% of the loss of the mangroves
  • Globally, half of all mangrove forests have been lost since 1950
  • According to Malaysian researchers, if just 2% of the world’s mangroves are lost, the amount of carbon released will be 50x the natural sequestration rate
51
Q

Research indicates that what percentage of the world’s mangrove forests may have been lost between 1980 and 2000?

A

At least 35%

52
Q

The Food and Agriculture Organisation (FAO) estimated that fishing supports how many people? What percentage of these people live in developing countries?

A

It supports 500 million people, of which 90% live in developing countries

53
Q

Fish provide what percentage of the annual protein consumption for 3 billion people?

A

16%

54
Q

Coral reefs shelter what percentage of marine species?

A

25%

55
Q

Example of a marine ecosystem for tourism?

A

Great Barrier Reef - Australia

56
Q

Human activity on coral reefs and marine species

A
  • Coral bleaching - affects food sources and incomes for those living in coastal communities
  • Tourism - reduces if the reef is damaged (damages local economies), tourism can lead to the damage (breaking off coral as a souvenir)
  • Climate change - research suggests that marine organisms may be responding faster to climate change than terrestrial plants and animals
  • Warming waters - killing cold-water plankton in the North Atlantic that North Atlantic cod are eating, Arctic krill stocks are declining by up to 75% in some parts of the Southern ocean
57
Q

Ocean acidification

A
  • Carbonic acid reacts with carbonate ions in the water to form bicarbonate
  • The higher the acidity, the more it dissolves carbonate shells
  • Ocean acidification has lowered the pH of the ocean by about 0.1. This means than it’s 30% more acidic than it was in 1750
58
Q

Which temperatures can coral survive in?

A

23-29°C

59
Q

Coral bleaching

A

It occurs when coral polyps expel the algae that live inside their tissue, causing the coral to turn white, due to a number of stresses such as light, temperature, or nutrients

60
Q

Climate scientists predict that surface temperatures will continue to rise, with increases in the range of ___°C between the years 2000-2100

A

2-6°C

61
Q

Uncertain future - economic growth (human)

A
  • After economic crashes (e.g. 2008 financial crisis), there is expectation that there’ll be a rise in emissions during recovery of global GDP
  • Fortunately, after 2008, emissions fell to 1% by 2012-13 down from 4%, then fell to 0.5% in 2014
62
Q

Uncertain future - energy source (human)

A

Energy consumption grew by 2% between 2008-2014, however renewables made up 2/3 of the increase in electricity production in 2015

63
Q

Uncertain future - population change (human)

A

Increasing affluence means a potential extra billion consumers by 2050, changing diets and an increase of mobility means more emissions

64
Q

Uncertain future - physical factors

A
  • Oceans and forests act as carbon sinks
  • Their response to increased GHG emissions and higher temperatures will continue to affect the global climate for possible hundreds of years
  • Deforestation - overall the amount of forested land is on a global decline
65
Q

Feedback mechanisms

A
  • These can either dampen or amplify responses to a changing climate
  • Peatlands - warming causes peat to dry out as water tables fall, increasing decomposition rates and releasing methane. A warming of 4°C causes a 40% loss of soil organic carbon from shallow peat, and 86% from deep peat
  • Permafrost - the melting of permafrost releases trapped carbon dioxide and methane
66
Q

Tipping points

A
  • A climate tipping point is a critical threshold whereby a carbon sink could become a carbon source
  • Two particular phenomena are capable of creating tipping points: forest dieback and changes to the thermohaline circulation
67
Q

Forest dieback

A
  • Rainfall in the Amazon basin is largely recycled from moisture within the forest
  • If the forest is subject to drought, the trees dieback
  • A tipping point can be reached when the level of dieback actually stops the recycling of moisture - resulting in further dieback
68
Q

Thermohaline circulation

A
  • Cold, deep water in the North Atlantic forms part of the thermohaline circulation
  • To keep the ‘conveyor belt’ or warm water heading from the Tropics towards Britain, heavy, salty water must sink in the North
  • However, melting of ice sheets releases large amounts of freshwater (less salty, meaning it’s lighter) into the ocean, blocking and slowing the conveyor down
  • As ice sheets melt, the ocean circulation is susceptible to a critical tipping point
69
Q

UK’s Department of Energy and Climate Change (DECC) policies - carbon taxation

A
  • The carbon price floor tax sets a minimum price companies have to pay to emit carbon dioxide
  • This policy was ‘frozen’ in 2015, most likely due to its unpopularity with both industry and environmental groups
  • Lower road taxes for low-carbon-emitting cars were scrapped in 2015
  • In 2015, oil and gas exploration tax relief was expanded to support fossil fuels
70
Q

UK’s Department of Energy and Climate Change (DECC) policies - renewable switching

A
  • The relationship between the big energy providers and the government dictates the amount of switching rom fossil fuels to renewables and nuclear power
  • Renewables provide intermittent electricity, while fossil fuels provide the continuous power essential for our current infrastructure
  • The Climate Change Levy, designed in 2001 to encourage renewable energy investment and use, was cut in 2015
71
Q

UK’s Department of Energy and Climate Change (DECC) policies - energy efficiency

A
  • The Green Deal scheme encouraged energy-saving improvements to homes, such as efficient boilers and lighting, and improved insultation. It was scrapped in 2015
  • Energy suppliers must comply with the Energy Company Obligation scheme to deliver energy-efficient measures to households
72
Q

UK’s Department of Energy and Climate Change (DECC) policies - afforestation

A

Tree planting in the UK is increasing, helping carbon sequestration. It involves the Forestry Commission, charities such as the National Trust and Woodland Trust, landowners and local authorities. The Big Tree Plant campaign encourages communities to plant 1 million trees, mostly in urban area

73
Q

UK’s Department of Energy and Climate Change (DECC) policies - CSS

A
  • Few actual geologic CSS projects exist globally, despite its potential. Canada’s Boundary Dam is the only large-scale working scheme
  • In 2015, the UK government cancelled its investment into full-scale projects at gas- and coal-powered plants in Peterhead in Scotland and Drax in Yorkshire
74
Q

Uncertain future - adaption strategies

A
  • Water conservation and management - smart irrigation, recycling sewage water, reducing agricultural consumption, conservation techniques, ‘real value’ prices for water
  • Land-use planning and flood-risk management - land-use zoning
  • Resilient agricultural systems - conservation cropping (growing crops using a no-tilling approach)
  • Solar radiation management - climate engineering
75
Q

Roles of different players - Global

A
  • UN
  • Roadmap to help local areas and communities take part in and work towards the Sustainable Development Goals
  • It has 5 different parts: awareness raising, advocacy, implementation, monitoring, and ‘where do we go from here?’
76
Q

Roles of different players - National

A
  • TNCs
  • Shell - invested heavily in the lowest-carbon biofuel, ‘New Energies’ business created in 2016 aims to explore investment opportunities in energy solutions (wind and solar with gas), ‘Shell Ventures’ established in 1996 invests in start-ups and small/medium enterprises to encourage scale and growth
  • Greenpeace - founded in 1971, priority campaigns (fossil fuels, deforestation, oceanic plastic), investigations into those responsible for environmental crimes, work with affected communities to identify solutions
77
Q

Roles of different players - Local

A
  • Winchester’s WinACC - lobby for local changes in attitude and actions
  • Began in 2007
  • The groups works with the local council to lower the carbon footprint of the Winchester District by inspiring sustainable living
  • Their aim is to cut the carbon footprint of the Winchester District by 60% and to ensure that at least 15% of the energy used in the district comes from local renewable sources by the end of 2020
78
Q

Roles of different players - Public

A
  • Online e-petitioning e.g. the 38 Degrees campaign
  • An online campaigning organisation, involving more than 2 million people from every corner of the UK
  • Launched in 2009, not-for-profit company
  • It aims to empower citizens by providing easy ways for people to take action against issues that they care about, including climate change
79
Q

Kyoto Agreement

A
  • Kyoto Protocol - an international agreement linked to the UN Framework Convention on Climate Change, which commits its parties by setting internationally binding emission reduction targets
  • Adopted in Kyoto, Japan, on the 11th December 1997 and entered into force on 16th February 2005
80
Q

Successes of the Kyoto Agreement

A

finish later

81
Q

Failures of the Kyoto Agreement

A

finish later

82
Q

Paris Agreement advantages

A
  • Countries can set their own individual targets
  • 195 countries signed up
  • Individual targets all work towards limiting temperature increase to 1.5°C above pre-industrial levels
83
Q

Paris Agreement disadvantages

A
  • No punishments if targets aren’t met
  • Signing the agreement and acting on it are two different things
  • A national effort is required for targets to be met, including public backing, which can be quite tricky
  • Progress reporting may not be accurate
  • Not a truly global agreement as developing countries are omitted that haven’t created the pollution