EQ3- How Are The Carbon And Water Cycles Linked To The Global Climate System Flashcards
Explain the process of slash and burn farming in forests and the degradation of carbon and water cycles affect on human wellbeing
Is used by 500 million landless farmers in rainforests around the world for subsistence. Farmers clear 2 hectares by cutting and burning trees where the ash adds nutrients to the soil.
Fire is caused and is one of the main causes of forest loss, as drier forest decays and is destroyed by fire, emissions of aerosols and wind blown soil results in reduced air quality and human respiratory problems.
Explain indigenous people and the degradation of carbon and water cycles affect on human well being
Indigenous people live in forests and rely upon it to live their life. The Efe tribe in Congo build the houses out of wood and leaves, would for cooking, hunts monkey for meat and fish the rivers, gather yam and nuts and use plants to make medicine
The palm oil industry has driven away indigenous people to meet the growing demand for palm oil
Explain the Kuznet’s curve and the different stages
Is based on economic principles. It suggests that as a country develops and enters stage one, damage to the natural environment will increase, as resources are exploited and pollution and degradation increases. As a country develops to stage two concern at environmental degradation leads to action to protect the environment. At stage three at high levels of development, education programs and funding occurs for environmental protection
Explain Indonesia’s forest moratorium
Aimed at reducing deforestation, with $1 billion of funding from the UN and Norwegian government.
The moratorium stopped issuing permits for the clearance of primary forests or peatland for timber and palm oil. In two years, emissions have fallen by between one and 2.5% and targets were set to reduce CO2 emissions by 26%.
However clearance payments that had already have been issued before the moratorium went ahead. Illegal logging remains a problem and has only reduced first loss by 15%
Explain the global expansion of forest areas
Between 2010 and 2015, 7.6 million hectares of forest we lost every year and 4.3 million hectors gained. The 3.3 million net annual loss was half of that in 1990
The temperate forest area has increased (Covering many HIC’s) although the tropical forest area has decreased (covering many LIC’s). Rates of forest loss of highest in low income countries
China aims to increase its forested area by 23% between 2015 and 2020
Brazil has halved it’s rate of deforestation since 2000
Define Land conversion
Any change from natural ecosystems to an alternative use, it usually reduces carbon and water stores and soil health
Explain the main drivers of deforestation
Due to increasing demand for commodity production. Most deforestation is for soy, palm oil, paper production and energy
Where in the world are levels of deforestation highest
Are highest in Indonesia and Brazil, both with an above 500,000 hectare loss and both tropical rainforest.
What were the main drivers of deforestation in Madagascar
Madagascar’s tropical rainforest has been cleared at a rapid rate, due to small scale clearance farming and growing international demand for tropical hardwood. Madagascar comply due to debt repayments.
Explain the implications to the carbon cycle, water cycle and soil health of deforestation
Has a major impact on the size of terrestrial stores, CO2 is released from decaying woody material , there is an increased carbon influx to the atmosphere from burning and the decaying of vegetation.
Soil erosion leads to a loss of nutrients and a large carbon store
Biomass is lost due to photosynthesis
The atmosphere becomes drier and there is reduced evapotranspiration
Where in the world are levels of afforestation highest
Highest in the USA and India. These countries are in stage 3 of the Kuznet’s curve model meaning they are at the stage of development where they now consider their impact on the environment
Why can afforestation be controversial
Is controversial in its impacts on landscape character. Often stores less carbon, uses more water and is disease prone.
However afforestation does sequester carbon
Where in the world has grassland conversion taken place for farming
Occurred in temperate grasslands, like the Savannah. Has fertile chernozem soil, an important carbon store, and is used for agriculture
Why are grasslands being converted for farming
Rapid increases in population has led to a high demand for food and resources
Why was there a big biofuel change in the US that lead to grassland conversion
Farmers were encouraged to grow corn, soya and canola due to the pressures of the US environmental protection agency
What are the implications for the carbon cycle from grassland conversion
The initial removal of grasslands releases CO2 from soils into the atmosphere
Annual ploughing enables soil bacteria to release CO2
Biofuel requires carbon based fertiliser producing a net increase in CO2
Soils are liable to erosion by runoff
Explain why physical factors can cause uncertainty in the projections of future atmospheric CO2 concentrations.
Oceans and forests act as carbon sinks and store heat. Ocean’s take decades to respond to changes in greenhouse gases concentrations , therefore accurately projecting future CO2 concentrations is difficult.
Explain why human factors cause uncertainty in the projections of future atmospheric CO2 concentrations
In many HIC’s we are observing forest gain but in many LIC’s we are observing forest loss, following Kuzent’s curve. Human factors such as population growth, economic growth and energy sources will have a huge influence on rates of deforestation in the future and this in turn will impact on future CO2 concentrations
Explain how positive feedback mechanisms (3) can cause uncertainty in the projections of future atmospheric CO2 concentrations
Permafrost stores a huge amount of carbon and methane. When permafrost melts, due to increased temperatures, it releases trapped CO2 and CH4 into the atmosphere, increasing atmospheric greenhouse gas concentrations and leading to further melting and increased temperatures, acting in a positive feedback loop amplifying change.
Peatlands store large amounts of carbon due to a low rate of decomposition in clogged waterlogged soil. Current and future warming causes peat to dry out as water tables fall, increasing the rate of decomposition and emitting carbon into the atmosphere as methane.
Reduced albedo of solar radiation by the earth’s surface as a snow and ice melt, darker surfaces absorb more heat energy and release methane.
The lack of control we have to limit these positive feedback mechanisms cause uncertainty in the projections of the extent it can reach and it’s effect on CO2 concentration.
Explain how negative feedback(3) causes uncertainty in projections of future atmospheric CO2 concentrations
Negative feedback naturally occurs to counteract the substantial effect of positive feedback mechanisms.
Increased cloud cover, due to higher rates of evaporation, will reflect solar energy, leading to lower temperatures and stable stores of carbon in permafrost and ice.
Increased plant growth as a result of higher CO2 concentrations will result in increased carbon stores in plants.
Dust from drier climates could enter the atmosphere and reduce the amount of incoming solar radiation.
The uncertainty with negative feedback mechanisms is that we are unable to project the extent to which negative feedback will counteract positive feedback and therefore reduce atmospheric CO2 concentrations
Explain how tipping points (2) cause uncertainty in the projection of future atmospheric CO2 concentration
There are seven tipping points identified by the IPCC, which are abrupt, possibly irreversible and large scale over a few decades
Forest die back is occurring in the Amazon rainforest, if it is subject to drought trees will die back and the point is reached where there is further die back due to trees no longer absorbing enough CO2 from the atmosphere. It is also occurring in the boreal forest where hot and dry summers leads to water stress and cause trees to die.
Changes to the thermohaline circulation – to keep the belt of warm water heading from the tropics towards Britain heavy, salty water must sink in the north. However the melting point of Northern ice sheets releases significant quantities of freshwater into the ocean which is less salty and thus blocking and slowing the belt. As Ice Sheets melt the ocean circulation is susceptible to a critical tipping point, a collapse in a thermohaline circulation may affect global temperatures.
Uncertainty over when these tipping points will be reached and the impact that they will have has caused uncertainty in future atmospheric CO2 concentrations
Explain water conservation and management as a adaption strategy for climate change
Exemplification
Benefits and drawbacks
Conservation and management of river water in relation to climate change, to manage limited supplies. Includes: smart irrigation and recycled sewage water for agricultural use.
Has been seen in Northern China, The Mekong river basin, where there is high demand for water due to agriculture. Water saving irrigation has been introduced in area’s of high demand.
B
In Northern China they have reduced water consumption by 12%
D
Can cause conflict between countries- In Israel water conservation and management has caused conflict with Palestine over water.
Explain Resilient agricultural systems as a adaption strategy for climate change
Exemplification
Benefits and Drawbacks
Involves growing crops using a ploughing approach, using fewer fertilisers and growing cover crops. Also involves strategies of growing crops designed to withstand higher temperatures.
Has been seen in Northern China, where early or late planting of plant crops has been introduced to withstand high temperatures.
B Uses fewer fertilisers Increased income for farmers Improved soil structure and health Erosion control In China, Maze yields increased by 15% with doubled grassland productivity and increased plant species.
D
Some parts of the world do not have the education, training or money to use this strategy
Explain Land use planning and Flood risk management as a adaption strategy for climate change
Exemplification
Benefits and Drawbacks
Area’s of increased risk, such as costal or river areas, can be zoned through urban planning and laws to prevent people and valuable property from being developed and instead low impact things like parks are placed there.
In Australia they are making all houses on floodplains more flood resistant, with raised floors, stronger foundations and water resistant materials. Reservoir levels are closely monitored to anticipate inundations and release water at safe levels.
B
Is a low cost approach to flood management
Reduces the human impact of flooding
Allows infiltration to occur naturally, reducing surface run off.
D
There is a high cost involved with relocating people
Reduces property values in rezoned areas
Locals will contest changes