Water Climate & Earth Flashcards
Both water and carbon are stored in the biosphere. Processes that transfer water and or carbon into and out of the biosphere involve both water and carbon. Identify three such processes and outline the way in which the water and carbon cycles work together.
• Photosynthesis requires both water and carbon. Photosynthesis converts energy from sunlight into biomass but cannot occur without water. Through food chains, the carbon stored in plants is passed onto animals, where it provides much needed energy for, breathing, growing and reproducing. Through respiration and decomposition, carbon is returned to the atmosphere in the form of CO2.
• Trees and plants are important in the transfer of water from the biosphere to the atmosphere, through the process of transpiration. Vegetation roots also help bind soil together reducing erosion and reducing water lost from an ecosystem through surface runoff. Consequently, the flood risk of area will be reduced if there is plenty of vegetation.
• Both water and carbon are stored in biomass.
Both water and carbon are stored in the atmosphere. Outline three ways in which the water and carbon cycles are interlinked in relation to transfers into and out of the atmosphere.
• Water is present in the atmosphere as water vapour. Like CO2 and methane, it is a greenhouse gas and helps keep the Earth warm enough to support life. Although there is a higher percentage of water vapour in the atmosphere than CO2, CO2 controls the amount of water vapour in the atmosphere (as it determines the rate of evaporation) and therefore the size of the enhanced greenhouse effect.
• Carbon combines with water in the atmosphere to form acid rain which allows chemical weathering, which removes carbon from the atmosphere and helps transfer it to the hydrosphere and biosphere.
• Carbon dioxide and water vapour are released during combustion, including from volcanic eruptions and burning fossil fuels.
Are there any processes in the water cycle that do not involve the carbon cycle in any way? Name any.
Evaporation (although rates of evaporation are determined by temperature which is affected by concentrations of CO2 in the atmosphere).
Are there any processes in the carbon cycle that don’t involve water?
None. The carbon cycle is dependent on the water cycle. Carbon dissolves in water and is therefore critical to many of the transfers of carbon between stores.
Outline a positive feedback loop in the carbon cycle linked to climate change.
- High levels of greenhouses gases in the atmosphere cause global temperatures to increase
- Increasing temperature causes permafrost to thaw
- Thawing exposes previously frozen organic matter to decay
- As organic matter decays it releases CO2 + methane into atmosphere
- Atmospheric CO2 and methane levels increase
Further warming
Outline a negative feedback loop in the carbon cycle linked to climate change.
- Global warming enhanced by CO2 emissions
- Higher temperatures and higher levels of CO2 increases photosynthesis rate and creates new areas of vegetation
- Co2 taken in by plants through photosynthesis
- Less co2 in atmosphere reduces global warming effect
- Photosynthesis returns to post-warming levels (no longer accelerated by co2 and global warming)
Outline a positive feedback loop in the water cycle linked to climate change.
- Warmer atmosphere holds more water vapour
- Water vapour is a greenhouse gas causing additional warming
- Warming of climate system
- Increased evaporation of water from earths surface
Outline a negative feedback loop in the water cycle linked to climate change.
- Increased co2 in atmosphere
- Increased greenhouse effect and warmer temperatures
- Increased evaporation from oceans
- Increased cloud cover + albedo
- Decreased temperature
- Back to equilibrium
Outline a negative feedback loop involving both the water and carbon cycles linked to climate change
• Increased CO2 in the atmosphere leads to warmer temperatures.
• Warmer ocean temperatures lead to higher concentrations of phytoplankton.
• Marine phytoplankton releases a chemical substance called dimethylsulphide
(DMS) that may promote the formation of clouds (condensation) over the oceans.
• More clouds result in a decrease in solar radiation.
• Global temperatures cool as a result.
Changes to the global pattern of precipitation:
Wet areas are expected to get wetter, and dry areas are expected to get drier. This could cause water shortages in some areas, which could lead to conflict in the future. The Sahel in Africa is an example of a region that is experiencing increasing water shortages and where desertification is putting pressure of local communities and animals.
Increased frequency on extreme weather events
This includes storms, floods and droughts. Although these will affect all continents, less developed countries will probably be worse affected, as they are less able to deal with the impacts. Countries like the Philippines have experienced many highly destructive typhoons over the last 30 years, including Typhoon Haiyan in 2013.
Decrease in agricultural productivity
This could lead to food shortages. The prices of major crops are likely to increase, with the poorest suffering most. Sub-Saharan Africa is likely to be particularly vulnerable.
Rise in sea levels
This will flood coastal and low-lying areas and will increase rates of coastal erosion. Area at risk include low-lying islands e.g. Tuvalu and The Maldives and densely populated countries in SE Asia, including Vietnam, Bangladesh and Japan. In Europe countries with low-lying and crowded coastlines are at risk, including The Netherlands, the UK and Ireland.
