EQ3: how are the carbon and water cycles linked to the global climate system?

Question 1

what are the four key ways the biological carbon cycle is being disrupted by human activity?

Answer 1

• resource exploitation and associated land-use changes

- indirect consequences of climate change and the enhanced greenhouse effect.

Question 2

what are three land-use changes associated with growing resource demands

Answer 2

• deforestation: the clearance of forests for timber and for the land they occupy (used for cultivating crops or livestock). however there is reforestation and afforestation occurring in temperate latitudes
• grassland conversion: temperate and tropical grasslands have become exploited by agriculture; suffered from over exploitation. the act of ploughing leads to an immediate loss of both CO2 and moisture, as well as run off characteristics
• urbanisation: the greatest land-use conversion where space is needed to accommodate a rapidly rising urban population and their widening range of economic activities.

Question 3

what is ocean acidification

Answer 3

ocean acidification involves a decrease in the pH (alkalinity) of the oceans caused by the uptake of carbon dioxide from the atmosphere.

Question 4

what is a carbon sink?

Answer 4

any natural environment (forest, wetland or ocean), that is capable of absorbing more carbon dioxide from the atmosphere than it releases to the atmosphere. The carbon sink function is the precursor to a particular environment becoming a carbon store.

Question 5

give evidence that ocean acidification has impacted the biological carbon cycle

Answer 5

up to the early nineteenth century, average oceanic pH was 8.2 but by 2015 had fallen to 8.1. there has been an even larger fall on surface waters especially in the pacific ocean, averaging a change of -0.08. coral reefs, an important component of ocean life, stop growing when the pH is less than 7.8

Question 6

give an example of how the rise in water temperatures have impacted the oceans carbon store

Answer 6

widespread bleaching of the coral in the Great Barrier Reef of Australia

Question 7

how is the health of the world’s forests being challenged

Answer 7

-by deforestation
-by the poleward shift of climatic belts
-by increasing drought
the three are connected in that the first and second are factors encouraging the third

Question 8

describe the Amazon drought

Answer 8

acts as a giant climate regulator- every day it pumps 20 billion tonnes of water into the atmosphere. the forests uniform humidity lowers atmospheric pressure, allowing moisture to form.
however since 1990, a cycle of extreme drought and flooding has been observed. Droughts in 2005 and 1010 greatly degraded much of the forest already stressed by prolonged and large-scale deforestation.

Question 9

what does the diminishing health of the tropical rainforest mean?

Answer 9

• declining as a carbon store
• sequestering less carbon dioxide from the atmosphere, thereby exacerbating the greenhouse effect
• playing a diminished role in the hydrological cycle.

Question 10

what are the key values of forests

Answer 10

-sequestering carbon dioxide from the atmosphere
-storing carbon
transferring moisture from the soil back into the atmosphere by evapotranspiration

Question 11

what does the Kuznets curve show?

Answer 11

The environmental Kuznets curve suggests that economic development initially leads to a deterioration in the environment, but after a certain level of economic growth, a society begins to improve its relationship with the environment and levels of environmental degradation reduces.

Question 12

when was the Forestry Commission set up in the UK and what were its aims and accomplishments?

Answer 12

1919
to remedy the country’s shortage of timber.
it began foresting fast-growing confers.
today 13% of the UK’s land surface is now forested.

Question 13

what are attitudes towards sustainability and environmental issues largely determined by?

Answer 13

motives:

if motives are economic profit, then attitudes towards the environment may not be sympathetic

Question 14

what are four key impacts of rising temperatures (specifically rising levels of water vapour)?

Answer 14

• impacts precipitation patterns
• impacts river regimes
• impacts drainage basin
• the cryosphere

Question 15

what has happened in the arctic as a result of rising temperatures?

Answer 15

• temps have risen twice as fast as the global average
• there has been a considerable loss of sea ice; the North-west Passage is now open to summer navigation
• much melting of the permafrost
• carbon uptake by terrestrial plants is increasing because of lengthening growing season
• loss of albedo as the ice melts. Sunlight that was previously reflected back into space is now being absorbed by the ever darkening land surface; which thus encourages further climatic warming- positive feedback loop

Question 16

what have been the benefits and consequences of the rising temperatures for human well being?

Answer 16

+warming of climate has opened up previously ice-bound wilderness areas to tourism.
+The exploitation of mineral resources, particularly Arctic oil and gas, is becoming more feasible
- climate warming is disrupted and perhaps annihilating traditional ways of life, for example the fishing and hunting Inuits of N America and the Sami reindeer of Northern Eurasia

Question 17

what are the impacts of declining ocean health due to acidification and bleaching?

Answer 17

changes to marine food webs; in particular, fish and crustacean stocks which are both declining and changing their distributions

Question 18

how is the declining ocean health impacting developing nations?

Answer 18

• the FAO estimates that fishing supports 500 million people, 90% of whom live in developing countries
• millions of fishing families depend on seafood for income as well as food
• seafood is also the dietary preference of some wealthier countries, notably Iceland and Japan
• Aquaculture is on the rise, but it’s productivity is also being affected by declining pH values and rising temperatures.

Question 19

how is tourism affected by declining ocean health?

Answer 19

-(Caribbean) coral reefs which are showing signs of degradation, have traditionally attracted scuba-diving tourists.
-rising sea level threatens the survival of tourism and its coastal infrastructure, as for example the Maldives.
the cost of strengthening coastal defences can often exceed the financial resources of poorer coastal countries.

Question 20

what are some future uncertainties regarding global warming?

Answer 20

• future GHG emissions
• GHG concentration levels (is there limited capacity?)
• resilience of carbon sinks and stores
• harnessing of renewable energy
• future economic development
• future population growth
• tipping point
• emissions from permafrost and peatlands

Question 21

what are the two different course of action to deal with the threat of global warming?

Answer 21

adaptation: changing our ways of living in such a manner that we are able to cope with most, if not all, of the outcomes of global warming
mitigation: reducing or preventing GHG emissions by devising new technologies and adopting low-carbon energies (renewables and recyclables).

Question 22

what are the five ways of ADAPTING to a changed climate?

Answer 22

• water conservation and management
• resilient agriculture systems
• land-use planning
• flood- risk management
• solar radiation management.

Question 23

what are the costs and benefits of water conservation and management as a form of adapting to a changing climate?

Answer 23

+fewer resources used= less groundwater abstraction
+attitudinal change operates on a long- term basis: used more grey/recycled water
-efficiency and conservation cannot match increased demands for water
-changing cultural habitats of a large water footprint needs promotion and enforcement by governments e.g smart meters

Question 24

what are the costs and benefits of resilient agricultural systems as a form of adapting to a changing climate?

Answer 24

+higher-tech, drought tolerant species help resistance to climate change and increase in diseases.
+more ‘indoor’ intensive farming
-more expensive technology, seeds and breeds unavailable to poor subsidence farmers without aid.
-growing food insecurity in many places adds pressure to find ‘quick fixes’

Question 25

what are the costs and benefits of Land-use planning as a form of adapting to a changing climate?

Answer 25

+soft management: land-use zoning, building restrictions in vulnerable flood plains and low-lying coasts
+enforcing strict runoff controls and soak ways
-abandoning high-risk areas and land-use resettling is often unfeasible, as is in megacities such as Bangladesh or Tokyo
-needs strong governance, enforcement and compensation

Question 26

what are the costs and benefits of flood-risk management as a form of adapting to a changing climate?

Answer 26

+simple changes can reduce flood risk e.g permeable tarmac
+reduced deforestation and more afforestation upstream to absorb water and reduce downstream flood risk
-debate over funding sources, especially in times of economic austerity
-constant maintenance is needed in hard management

Question 27

what are the costs and benefits of solar radiation management as a form of adapting to a changing climate?

Answer 27

+the proposal is to use orbiting satellites to reflect some inward radiation back into space; could cool the earth within months and be relatively cheap compared to mitigation
-would reduce but not eliminate the worst effects of GHG’s, for example, it would alter acidification.

Question 28

what are the 5 key mitigation methods applied in the UK?

Answer 28

• carbon taxation
• renewable switching
• energy efficiency
• afforestation
• carbon capture and storage.

Question 29

what is the UK department of energy and climate change’s (DECC) policies

Answer 29

• carbon taxation: carbon tax sets a minimum price that companies have to pay to emit Co2
• renewable switching: relationship between big energy supplier and gov. dictate the switch from fossil fuels to renewables and nuclear power.
• energy efficiency: green deal scheme encouraged energy-saving improvements to homes
• afforestation: tree planting schemes such as The Big Tree Plant (which planted 1 million trees in urban areas) is designed to attempt to reduce Co2 emissions
• carbon capture and storage: In 2015, the Uk cancelled its investments into a full scale projects at gas- and coal- powered plants in Peterhead, Scotland and Drax in Yorkshire

Question 30

what are the four potential futures proposed by the Intergovernmental panel on Climate change (IPCC)

Answer 30

1. ‘Business as usual’: emissions continue rising at current rates
2. ‘Some mitigation’: Emissions rise to 2080 then fall
3. ‘Strong mitigation’: Emissions stabilise at half todays level by 2080
4. ‘Aggressive mitigation’: Emissions halved by 2080

Question 31

when and where was it first accepted that Global warming is a global problem, requiring global action?

Answer 31

Kyoto Protocal 1997 : aimed to cut GHG emissions by 5% by 2012.
(more recent)
Copenhagen (2009)
Paris agreement of 2016: aimed to keep the rising global temps below 2°c above pre-industrial level. the Agreement now has 140 national signatures (including largest producers China and India and had USA but they pulled out in 2017).