ELSS SG6 Flashcards
How are the carbon and water cycles linked via the atmosphere?
Both water and carbon are stored and transferred to and from it
How are the carbon and water cycles linked via the oceans?
Global warming - atmospheric CO2 levels rise. More infrared radiation is trapped within the atmosphere which causes the enhanced greenhouse effect. This leads to global warming
What are four impacts of global warming on oceans?
Sea surface temperatures rise causing more evaporation, As oceans warm thermal expansion occurs which contributes to rising sea levels, The ability of the oceans to absorb CO2 decreases leading to a higher atmospheric store, Increased melting of ice sheets and glaciers causes sea levels to rise
How are the carbon and water cycles linked via the vegetation and soil?
Changes in the water cycle, soils and vegetation leads to implications on carbon cycle stores and transfers
How are the carbon and water cycles linked via the cryosphere?
A change in the cryospheric store of water not only causes a change in the flows and stores of water, but creates a positive feedback loop which changes the stores and flows of carbon
What are four global management strategies to protect the carbon cycle?
Afforestation, Wetland restoration, Improving agricultural practices, International agreements to reduce carbon emissions
Define Afforestation
Planting trees in deforested areas, or in areas which have never been forested
What are three reasons afforestation can protect the carbon cycle?
Planting trees removes CO2 from the atmosphere through photosynthesis, Tree planting could sequester 1.1-1.6 GT/year of carbon, Agroforestry grows quicker and absorbs higher rates of CO2 than normal forests
What are two limitations of afforestation?
Total global greenhouse gas emissions equivalent to 50 GT of CO2 in 2004 greatly exceed the amount that can be sequestered by afforestation schemes, The high cost of afforestation means it is not done on a large scale
Define Wetlands
Where the water table is at or near the surface causing the ground to be permanently saturated e.g. marshes, peatlands and floodplains
What are wetlands a large store of carbon?
Decomposition is greatly reduced in waterlogged soil from lack of oxygen
Why have wetlands been destroyed in the past?
Population growth, economic development and urbanisation have put huge stress on wetland areas
What is the impact of destroyed wetland?
Huge amounts of CO2 and CH4 transferred to the atmosphere
Define Wetland Restoration
Rehabilitates a degraded wetland or re-establishes a wetland that has been destroyed
What does wetland restoration focus on?
Raising local water tabes to re-create waterlogged conditions
What are three reasons wetland restoration WILL have a significant impact on protecting the carbon cycle?
One hectare of seagrass can store 2x as much carbon than an average terrestrial forest the same size, Coastal wetlands store 50% of the seabed’s rich carbon reserves, Coastal wetlands sequester enough CO2 to offset the burning of 1 million barrels of oil
What are two reasons wetland restoration WON’T have a significant impact on protecting the carbon cycle?
Not all wetlands are effective as carbon sinks - some are sources due to slow decomposition of organic matter, Wetland drainage releases CO2 into the atmosphere
What % of greenhouse gas emissions come from land use or soil management?
40%
What % of greenhouse gas emissions is methane from livestock?
30%
What % of What % of greenhouse gas emissions is from deforestation?
20%
What % of greenhouse gas emissions comes from wetland rice and manure management?
10%
What are four problems of current farming practices?
Tillage, Tree clearance, Soil compaction, Ploughing
Define Tillage
Turning the soil to control for weeds and pests, and to prepare for seeding
How does tillage impact the carbon cycle?
Intensive soil tillage can increase the likelihood of soil erosion, nutrient runoff into nearby waterways and the release of carbon into the atmosphere
How does tree clearance impact the carbon cycle?
As forests are cleared, they expose the land to direct attack from wind and rain causing soil erosion which releases carbon (and other nutrients) into the atmosphere and rivers
How does soil compaction impact the carbon cycle?
The use of heavy machinery on wet soils leads to compacted subsurface soil layers which decrease infiltration and increase runoff, leading to soil erosion
How does ploughing impact the carbon cycle?
Ploughing progressively destroys soil organic matter by oxidation as it is exposed to the atmosphere, leading to carbon being released to the atmosphere
What is a solution to tillage?
Zero tillage - a reduction in how often or intensively cropland is tilled
How does zero tillage help protect the carbon cycle?
It enables the soil to retain more organic matter which leaves the soil less susceptible to wind and water erosion and helps store carbon
What is a solution to soil compaction?
Avoiding using heavy farm machinery on wet soils
How does polyculture help protect the carbon cycle?
Trees provide year round ground cover and protect soils from erosion, therefore preventing the loss of carbon
How does avoiding using heavy farm machinery on wet soils help protect the carbon cycle?
Prevents the soils becoming compacted and water is able to infiltrate the soil, leading to less soil erosion
How does contour ploughing help protect the carbon cycle?
The ridges or dams slow water flow, controlling overland flow, increasing infiltration and therefore reduces soil erosion by up to 50%
What is the United Nations Framework Convention on Climate Change (UNFCCC)?
Created in 1992 as the main forum for international agreement on tackling climate change
What does UNFCCC stand for?
United Nations Framework Convention on Climate Change
What was the aim of the Kyoto Protocol (1997)?
Industrialised countries must aim to cut their overall greenhouse gas emissions (GGE) to 5% below 1990 levels by 2012
How many countries signed the Kyoto Protocol?
175
What were three problems encountered with the Kyoto Protocol?
CO2 has a very long lifetime in the atmosphere of 100 years so concentrations respond very slowly to any target reductions in emissions,
What were three problems encountered with the Kyoto Protocol?
CO2 has a very long lifetime in the atmosphere of 100 years so concentrations respond very slowly to any target reductions in emissions, LIDCs were not included in targets, Despite being the biggest contributors to GGE the USA, China, India and Australia didn’t sign the protocol
What is a reason the Kyoto Protocol WAS a success?
37 countries collectively reduced their output by 2GT per year from 2008 to 2012 compared to 1990 levels
What are three reasons the Kyoto Protocol WASN’T a success?
27 countries failed to meet their target, 10 countries only managed to achieve their target by buying carbon credits, The largest emitters didn’t sign so it didn’t make a big difference in global emissions
What is the aim of the Paris Climate Summit (2015)?
To reduce global CO2 emissions below 60% of 2010 levels by 2050 and keep global warming below 2 degrees C
Define Intended Nationally Determined Contributions (INDCs)
Voluntary pledges setting out how countries plan to limit their greenhouse gas emissions during the 2020s
What are two problems encountered with the Paris Climate Summit?
There are no fines or penalties is countries do no achieve their INDCs, The emissions pledges so far still leave the world on track for at least 2.7 degree C warming this century
Define CAP and Trade
A business receives an annual carbon quota (credits) which can be bought/sold on international carbon markets
Define Carbon Offsetting
An internal scheme to control carbon emissions where polluters either cut their emissions or incur extra costs by buying carbon credits
Define Carbon Credits
Allowances that permit given levels of CO2 emissions by businesses, excess emissions must be covered by trading carbon credits
What are three global management strategies to protect the water cycle?
Improving forestry techniques, Water allocations, Agricultural practices
What does ARPA stand for?
Amazon Regional Protected Areas
What does ARPA aim to do?
Reduce deforestation by expanding and consolidating areas under strict protection
What is ARPA working to do?
Increase the total area under strict supervision to 10% of Brazil’s Amazon basin, adding 25 million hectares to the 12 million already under protection
Define Agroforestry
Food production combined with tree planting
How does agroforestry protect the water cycle in the Amazon Rainforest?
If food is produced alongside tree planting, it reduces the need to clear large areas of forest for agricultural practices
What does REDD stand for?
Reduced greenhouse gas Emissions from Deforestation and forest Degradation
How does REDD protect the water cycle in the Amazon Rainforest?
Ensures that trees are protected by local indigenous tribes e.g. the Suri tribes
What % of water is used for agriculture globally?
70%
What % of water is used for agriculture in LIDCs?
82%
What % of water is used for industrial use in ACs?
59%
What are two ways to ensure balanced use of water?
Understand how all the different water stores work together then analysis the different uses of water, Involve all the different parties in the decision making process to ensure that everyone gets access to water
What are three features of a successful integrated river basin management scheme?
Stakeholders have to be realistic (e.g. about how much food they can grow), Have to make sure everyone gets the water they need, When its drier you have to adapt to there being less water
What prevents the success of integrated river basin management schemes?
Unless all groups are involved, it will not work
What are two examples of successful integrated river basin management schemes?
The USA clean water act and the European water framework directive has improved water quality, The Danube River has successfully reduced water pollution
What are two ways drainage basin planning can protect the water cycle?
Specific targets for drainage basin planning include runoff, surface water storage and groundwater storage, Rapid runoff is controlled by reforestation programmes in upper catchments reducing artificial drainage and extending permeable surfaces
What are five strategies to make water use more efficient in agriculture?
Drip irrigation, Mulching of crops with organic matter, Crop breeding, Contour ploughing, Rainwater harvesting
How does drip irrigation make water use more efficient in agriculture?
Rather than water being transported by sprinkler systems or irrigation channels (where it is exposed to evaporation) this leaks water gradually from pipes running in or on the soil to minimise water damage
How does mulching of crops with organic matter make water use more efficient in agriculture?
Reduces evaporation and increases water storage in the soil
How does crop breeding make water use more efficient in agriculture?
Genetically modified crops can survive on much lower water levels, so less water extraction and irrigation is needed
How does contour ploughing make water use more efficient in agriculture?
The ridges slow water flow, increasing the most efficient use of water by slowing runoff
How does rainwater harvesting make water use more efficient in agriculture?
The collection of rainwater off barn roofs and storage in giant tanks or specially dug ponds will reduce the amount of water that needs to be extracted from local water sources
