Please enable JavaScript.

Coggle requires JavaScript to display documents.

Water and Carbon cyle - Coggle Diagram

- - - - Is a chemical process that happens in animal cells glucose is converted into energy and can be used for growth and repair + movement and control of body temperature (homeostasis). Carbon dioxide is then returned into the atmosphere via exhalation (exhaled air).
    - - When organisms die they are consumed by decomposers such as bacteria (saprobioents), fungi, and earthworms. During this process carbon from their bodies is returned to the atmosphere as carbon dioxide via respiration.
    - - Organic material contains carbon and when its burnt in the presence of oxygen (e.g. coal in a power station) is converted into energy into carbon dioxide and water. Combustion is when carbon dioxide is released into the atmosphere and returns carbon that might have been stored in rocks for millions of years.
    - - This is when organic matter is buried by sediments and becomes compacted over millions of years. In a couple of million years after the organic matter is buried these sediments form hydrocarbons such as coal and oil.
        Corals and shelled organisms take up carbon dioxide from the water and convert into calcium carbonate which is then used to build the shells, when they die they accumulate on the sea bed causing some of the carbonates to dissolve releasing carbon dioxide but the rest become compact to form limestone storing carbon for millions of years.
    - - Carbon sequestration is an umbrella terms used to describe the atmosphere to plants, soils, rock formations and oceans. Sequestration is a human process carbon capture + storage (CCS) is a term used for technological capturing emitted from power stations smaller scale sequestration can take place in farming practices.
    - - Weathering involves the breakdown or decay of rocks in their original place at or close to the surface. when carbon dioxide is absorb by rainwater it forms mildly acidic carbonic acid and through a series of complex chemical reaction rocks will dissolve releasing carbon.
  - - - Natural climate change
        
        During the quaternary period (2.6 million years ago to present) global temperature fluctuated considerably between interglacial (warm) and glacial (cold) periods
      - Impacts of cold conditions on carbon stores and transfers
        
        Chemical weathering processes would have been more active because cold water can hold more carbon dioxide.
        Forest coverage would be very different both in total area and in geographical location. This would have affected the significance and distribution of processes such as photosynthesis and respiration.
        Decomposers would have been less effective, so carbon transfer so soils would have been reduced.
        Less water would have flowed into the ocean as it was locked up as snow and ice on land. There would be less sediment transfer along rivers and less build up of sediment on the ocean floor.
        The soil would have been frozen over vast areas of land. This would have stopped transfers of carbon
    - - This type of physical factor returns carbon to the atmosphere that has been trapped in the earths' crusts for millions of years, an example can be the Palaeozoic era (542-251 million years ago) volcanoes were much more active than they are today meaning a vast amount of carbon dioxide was emitted into the atmosphere and remain for a long time but at present volcanoes emit 130 to 180 million tonnes of carbon dioxide per year however, in comparison to 30 billion tonnes per year. Volcanoes erupt lava containing silicates that slowly will weather converting carbon dioxide in the air into carbonates, in this way carbon dioxide is absorb from the atmosphere very slowly.
- - - - A cyclical sequence of events that amplifies or increases change. Positive feedback loops exacerbate the outputs of a system, driving it in one direction and promoting environmental instability.
    - - A cyclical sequence of events that damps down or neutralises the effects of a system, promoting stability and a state of dynamic equilibrium.
    - - This represents a state of balance within a constantly changing system.
  - - - Lithosphere (land), Hydrosphere (liquid water), Cryosphere (frozen water - snow and ice) and Atmosphere
        
        Only 2.5% of the Earth's water is stored as fresh water almost all of which are stored as snow or ice.
        
        Surface and other freshwater comprises only 1.2% of all freshwater.
        
        The vast majority of Earth's saline water (97.4%) is stored in oceans.
    - - Water stores have geographical components that is not evenly distributed evenly across the world
      - What is the global distribution of groundwater aquifers?
        
        Just over 30% of freshwater is stored in rocks deep below ground surface forming underground reservoirs called aquifers.
        Aquifers contains rocks such as chalk and sandstone and are permeable as they have pores allowing water to infiltrate.
        The variation in capacity to store water in the soil is called the soil water budget. The soil is porous allowing water to seep through and is easily transferred.
  - - - The Earths land area was locked up by glaciers with water dropping sea levels by over 100 metres compared to present day.
        During warmer periods about 3 million years ago water levels were about 50 metres higher than they are today as the amount of water stored as snow declined.w
    - - The global atmospheric circulation model simplifies to suggest the presence of 3 cells called the Hadley cell, Farrell cell and the polar cell.
        
        At the Hadley cell there is high evaporation rates as the warm and moist air rises, cools and condenses to form clouds this mainly occurs at the equator this is caused at the low pressure zone called the ITCZ (inter tropical convergence Zone) causing there to be high rates of precipitation.
    - - 95% of Earth's frozen water is stored in Antarctica and Greenland. Snow falling on glaciers and ice sheets have become compressed and is long term stored as glacial ice.
        This can be drilled through as even find 40,000 year old ice.
        The melting of freshwater ice has caused sea levels to rise 60m adding a great deal to the ocean water store. This can be identified as a positive feedback loop whereby rising sea levels destabilise ice shelves, triggering calving and further melting.
        
        Hill slope water cycle
        
        The hillslope is effected by various human and natural factors such as deforestation, urbanisation, agriculture, storms and seasonal changes.
        
        Influential factors of this can be infiltration as the movement of water from grounds surface through the soil.
    - - The water table measures the boundary between water-saturated ground compared to unsaturated ground.
  - - - This is an input that increases interception via plants and trees where it is stored before it is evaporated but increases stemflow within the plants.
    - - Groundwater flow feeds rivers water through their banks and stores water once rained and the water has infiltrated through or percolated. This can suggest why that rivers carry on flowing through dry periods.
- - - - Land use changes that impact the water cycle the most is deforestation and urbanisation:
        Urbanisation is the replacement of vegetated ground for impermeable surfaces such as concrete and tarmac meaning water can't infiltrate through the ground increasing overland flow (surface runoff) which effectively decreases soil water and ground stores.
        Deforestation decreases evapotranspiration and can also lead to soil erosion and an increase in surface runoff and soil erosion which reduces soil stores.
    - - Farmers control the local water cycle via irrigation or land drainage. soils covered plants have higher infiltration and soil water rates and there for reducing surface runoff.
        If desertification occurs, the capacity to retain water is much lower. This capacity is lost completely once the soil is sealed.
    - - The extraction of water from rivers or groundwater aquifers is referred to as water abstraction. Water is abstracted for irrigation, industry and domestic purposes can have significant effects on the local water cycle.
        Aquifers can become depleted as they can also become contaminated by inflowing saltwater if the water table drops below sea level this has become a issue with London's chalk aquifer.
        Abstraction can result low flow conditions in rivers which can impact ecosystems harmfully.
    - - This has a significant impact on water stores (aquifers and rivers) and transfer processes (evaporation and infiltration). In parts of the middle east, water is being abstracted from underground aquifers that were formed thousands of years ago and are in serious danger of being depleted as the rate of charge is slower than the usage of water.
- - - - The Amazon Basin consists of 670 million hectares and is the worlds largest rainforest and is one of the most biodiverse consisting of 300 billion trees with 15,000 species store one fifth of all the carbon in the planets biomass.
        The rainforest has been in South America for 55 million years and was spread all over the continent but has shrunk and grown repeatedly as the ice ages came and went but recently has begun shrinking due to deforestation as 34 million people depend on its resources
      - Effects on carbon and water cycle
        
        Carbon
        
        The Helmholtz centre for environmental research (UFZ) estimated that the Amazon stored 76 billion tons of carbon in 2019, along with other rainforests acting as carbon sinks storing 1-3 GtG a year.
        However, studies show that ground biomass have been increasing 0.3 to 0.5 percent a year which rises productivity of tropical forests due to increasing carbon dioxide concentrations in the atmosphere. This is a resulting in a negative feedback loop seeming to offset levels of carbon dioxide
        The UFZ have estimated that in 2019 the Amazon Rainforest was a carbon sink absorbing around 600 million tonnes per year. This was much less than peak of two billion tonnes of carbon dioxide stored in 1990.
        Although with the massive increase in atmospheric carbon dioxide levels this has resulted a growth spurt in trees causing trees to grow faster but die younger which has led to a surge of trees that are dying in the Amazon.
        
        water
        
        The average discharge of the Amazon is around 175,000 metres cubed a second that goes into the Atlantic ocean or around 15% of fresh water enters the ocean each day.
        The Rio Negro is a tributary of the Amazon and is the second largest river in the world in terms of water flow and is 100m deep and is 14km wide and is near Manaus, Brazil.
        Average rainfall is around 2300mm annually but in the North West the amount of precipitation can exceed 6000mm annually and up to half will never reach the forest floor as most of it is intercepted from the canopy of the forest which then half of which is intercepted is then returned into the atmosphere by evaporation from plants and leaves, only 48% of this water is returned as rain. Out of the 48% only 30% reaches the sea and the rest is caught up in a loop.
      - Drivers of change
        
        Deforestation in the Amazon between the years 2000 and 2007 a forest large than the size of Greece was cut down (19,368km squared).
        Brazil is the 4th largest climate polluter in the world as 75% of Greenhouse gasses are attributed by deforestation and land use change with 59% of this being from the burning and loss of the Amazon.
        The slash and burn technique reduces humidity in the canopy layer and one metre down and makes evapotranspiration easier, increases albedo and temperature and reduces porosity of the soil making it easier for soil erosion to occur as soil is washed away when precipitation occurs.
        salts and organic fibres act as condensation nuclei which assist in the formation of clouds and rain, with their loss this inhibits cloud and rain formation.
        Rainforests absorb approximately 11% of solar radiation.
        Average temperature is 24.1 degrees in pastures its 33 degrees.
        daily temperature variation in soil at 20cm don't exceed 2.8 degrees but under pastures 8 degrees.
    - - Indonesia's rainforests is one of the most biologically and culturally diverse landscapes in the world, recently in the 1960s 80% of Indonesia was covered in rainforest but rapid development has decimated the natural rainforest as the increase in demand for paper, pulp, plywood and palm oil, along with allegations of corruption and disputes over land rights. However, the significant increase in deforestation rates have caused a disruption in the water and carbon cycle by altering the magnitude in stores and flows.
        Indonesia has one of the highest deforestation rates in the world as just under half of the original forest cover remains but conservative studies suggest that more than a million hectares (2.4 million acres) of the rainforest is lost each year with 70 percent occurring in forest on mineral soils and 30 percent on carbon rich peatland forests, once the peatlands are exposed it is then easily eroded by wind, rain and increased rates of decomposition of dead organic matter (leaves) that cause a further increase in carbon dioxide being released into the atmosphere. As the forest is lost to deforestation the area for a carbon sink is heavily reduced and now becomes a carbon sink as more forest is being lost than recovered.
      - A major environmental characteristic and catastrophies of deforestation has been the prevalence of fires that are often widespread and left to burn out of control as they burn quick to clear land to prior development for commercial developments such as growing palm trees for palm oil.
        During the last couple of decades forest fires have caused black smoke into the atmosphere that have released large quantities of carbon back into the atmosphere that had been stored for hundred of years.
        All this burning has caused Indonesia to become the third largest emitter of greenhouse gases (GHGs) behind the US and China as 85 percent of its emissions are derived from rainforest peatland degradation and loss. In 1997 and 1998 the growth rate of carbon dioxide had suddenly reached the highest record the majority coming from the forest fires in Indonesia that started in 1997 and in '98, these forest fires had contained smoke particles that caused haze to neighboring countries.
        However, when the forest fires had stopped over 8 million hectares had been burnt. Scientists that extra carbon that has been burnt into the atmosphere was more than all the carbon that living things on earth remove from the atmosphere in one year.
    - - The warm and tropical climate is ideal for plant growth, promoting photosynthesis which absorbs large amount of carbon dioxide from the atmosphere and releases large amount of oxygen suggesting rainforests emit large amounts of oxygen giving rainforests the nickname of the human lung.
        Wood is around 50% of carbon so rainforests plants and trees are a huge store of carbon and are important carbon sinks which aid in mitigating effects of global warming.
        However, even though are large amount of carbon is stored in trees and plants some carbon is emitted via respiration in plant, trees and mammals returning some carbon back into the atmosphere.
        Decomposition is an active process in rainforests as bacteria and fungi thrive under these conditions that are warm and wet so there for this process releases carbon back into the atmosphere by respiration.
        Carbon can be stored in soils or dissolved and can be removed by streams as an output from the rainforests
      - What is the impact of human activity and environmental change?
        
        Certain impacts such as farming, mining, roads and settlements impacts rainforests are cleared for these main reasons but the most common clearing methods is slash and burn which is a cheap and a very effective method, however, can spread like wildfires. Deforestation is one of the main contributors of greenhouse gases that are mainly responsible for climate change.
        Effects deforestation can have on the carbon cycle:
        Photosynthesis mainly ceases, until new plants start to colonise the area meaning this is the most significant impact on deforestation on the carbon cycle.
        Plant and animal respiration drops to almost zero.
        Rain washes ash into the ground increasing carbon content of the soil but carbon in runoff can increase too.
        Decomposers will be largely absent from this environment.
        Replacing rainforests with alternative land uses such as crops and pasture can reintroduce flows and stores but to less effective levels compared to grassland absorption with tropical rainforests.
        Human activity such as mineral mining has impacts on the carbon cycle in parts of Malaysia were this is managed with strict logging laws by replanting which has both sustainable and little impacts on the carbon cycle.