Earths life support systems

Question 1

Distribution and size of major stores in the carbon system

Answer 1

. Carbonate rocks such as limestone, chalk and deep ocean sediment (largest)

. Oceans ( Second)

. Atmosphere (Small but represents most of the caarbon in circulation at any one time)

. Living and dead organic matter below and above ground
. Tropical and boreal forests

Question 2

Characteristics and main inputs and outputs of the carbon cycle

Answer 2

. Precipitation (Rainfall becomes acidic as CO2 dissolves)

. Photosynthesis

. Decomposition

. Respiration

. Combustion (When organic matter burns in the presence of oxygen)

. Weathering (Chemical weathering, carbon rocks dissolved into streams and rivers)

Question 3

Water cycle in the Arctic - rates of flows and stores

Answer 3

. Low annual precipitation most of which falls as snow
. Limited transpiration as sparse vegetation and short growing season
. Low evaporation - most of the energy used on melting snow
. Limited groundwater and soil moisture stores
. Permafrost is a barrier to infiltration, percolation, recharge and groundwater flow

Question 4

Carbon cycle in the Arctic

Answer 4

. Permafrost is a carbon sink
. Flow of CO2 concentrated in summer when active top layer melts
. Decomposition takes place
.

Question 5

Physical factors affecting flows and stores in the water cycle

Answer 5

. Temperature - average monthly temp is below freezing, only top layer thaws in summer
. Water unable to be absorbed when thawed in the summer
. Waterlogging as minimal land relief
. Chaotic glacial deposits obstruct drainage

Question 6

Physical factors affecting flows and stores in the carbon cycle

Answer 6

. Temp - Permafrost keeps carbon frozen
. Largest proportion of organic matter found in the soil, slow decomposition so 5x vegeation stored
. Snow insulates microbes so slow decomposition
. Lots of freeze thaw causes cryoturbtion (mixing) of past glaciers and rocks which forms the soil

Question 7

Impact of developing oil and gas industry on carbon cycles

Answer 7

. Oil and gas discovered in Prudhoe bay 1968, extracting it is hard due to conditions
. Installing infrastructure and machines diffueses heat
. Dust makes soil black so sunlight is absorbed
. Vegetation is removed, recovers slowly, insulates permafrost
. Thawing soil releases CO2 and gas and oil spills too

Question 8

Impacts of developing oil and gas industry on water cycle

Answer 8

. Melting permafrost and snow increases runoff and river discharge increasing flood risk
. Ponds and lake form due to melting increasing evaporation
. Mining gravel and sand creates lakes, disrupts drainage and permafrost
. Drainage networks disrupted by road construction
. Explosions used for oil and gas
. Water extracted from creeks and rivers for industrial use leading to decreased localised water storage

Question 9

Impact of fossil fuel comobustion and carbon sequestration on flows and stores of carbon

Answer 9

. Industry depends on carbon, 87% of energy in 2013
. 10 billion tonnes of CO2 into atmosphere per year
. 2000 anthropogenic emissions of CO2 since 1750

Carbon sequestration - storage of waste carbon, solution to capture and store carbon from factories - injected into porous rocks underground - 40% of US Carbon comes from power station, CCS reduce this by 90%

Expensive, need porous rocks, more than 1 billion costs

Question 10

How human activitites cause changes in the availability of carbon stores

Answer 10

. Rapid population and economic growth , deforestation and urbanisation
. increased demand for water, Lake Mead Las Vegas has fallen drastically
. Over pumping water from aquifers in Bangladesh creates salt water incursion making water unsafe
. Deforestation breaks the cycle of water transferring from biosphere and atmosphere

Question 11

How human activites cause changes in the availabity of carbon stores

Answer 11

. World relies on fossil fuels for 82% primary energy consumption

. Deforestation transfers 1 billion tonnes of carbon into the atmosphere

. Mass deforestation has decreased Earth’s forest cover by 50%, Carbon stores by photosynthess decreased

. Acidification of thhe oceans threaten phytoplankton which absorb more than half the volume burning CO2 creates

Question 12

Impact of long term climate change on water cycle

Answer 12

. Increased evaporation thereofre increased water vapour - natural greenhouse gas
. Incrased precipitation creates increased runoff and flood risk, water vapour is a source of energy in the atmosphere - more intense storms and hurricanes
. Ice and glaciers melt

Question 13

Impact of long term climate change on carbon cycle

Answer 13

. Increased decomposition, greater transfer of carbon to biosphere
. Carbon released in permafrost
. Acidifcation of oceans through absorption of CO2 decreases absorption by phyoplankton limiting capacity of oceans to store carbon

Question 14

Implications of water and carbonmanagement (Reducing emissions)

Answer 14

.Carbon trading scheme, every business has set amount of emissions space, if they need more they can pay for it
. International agreements are risky as some countries focus on their own deevelopment
. Kyoto protocol 1997 didnt work
. Redone in Paris agreement 2015

Question 15

Implications of water and carbon management (Improving agricultural practises)

Answer 15

. Growing crops without ploughing soil to conserve soils organic content, reduce oxidation and reduce erosion by the wind and rain. Growing crops amongst the trees to protect the soil from erosion
. Leaving crop residue in soil to put nutrients back into the soil via decomposition

Question 16

Processes which control the short term changes to the cycles (Diurnal (daily) changes)

Answer 16

. Lower temperatures at night decrease evaporation

. Carbon flows from atmosphere to vegetation through photosynthesis
. At night respiration releases carbon into atmosphere