changes in the carbon stores overtime

Question 1

fossil fuels-HUMAN IMPACTS

Answer 1

combustion transfers co2 to the atmosphere from a long term carbon sink

• 64% of human caused carbon is combustion of greenhouse gases
• co2 emission dominated by India, china and use

Question 2

farming- HUMAN IMPACT

Answer 2

when soil is ploughed, the layers mix and soil microbial activity increases-this causes organic matter to be broken down and carbon is lost to the atmosphere

• tractors also emit co2
• largest source is from Agriculture from enteric fermentation which releases methane(25 times stronger, livestock produce 14% of human induced emissions)
• biological processes in rice paddies generate methane which makes 10% of emissions-44% of agricultural emissions are from Asia

Question 3

deforestation- HUMAN INPACT

Answer 3

• done to clear space for farming, logging, infrastructure and urban sprawl
• uses slash and burn causing carbon to be released quickly
• it accounts for 30% of human induced emissions

Question 4

wildfires- NATURAL IMPACTS

Answer 4

• transfers carbon from biosphere to atmosphere as co2 is released through burning
• loss of vegetation decreases photosynthesis so less carbon is removed
• in the long term fires can encourage the growth of new plants which take in carbon from the atmosphere for photosynthesis

Question 5

volcanic activity-NATURAL IMPACT

Answer 5

carbon stored within the earth is released during volcanic eruptions
they contribute a very low proportion of co2
-EXAMPLE mt tambour-sulphur dioxide blocked radiation from sun which lowered global temps

Question 6

land use change- HUMAN IMPACT

Answer 6

• change of land use from natural to urban is a major source of carbon
• vegetation is removed to make way for buildings which reduces carbon storage in biosphere
• concrete production releases a lot of co2
• co2 is also increased through transport, industry and domestic use
• land use change accounts for a tenth of carbon released annually

Question 7

carbon sequestration=

Answer 7

involves putting co2 from the atmosphere into long term storage

Question 8

geological sequestration=

Answer 8

co2 is captured at its source and then injected as a liquid underground in gas reservoirs or depleted oil
the advantage of storing it in deep oceans is it sinks within weeks once it reaches the seabed it enters the geological cycle

Question 9

biological sequestration

Answer 9

involves the use of plants to capture co2 from the atmosphere and then to store it in the roots of plants. the aim is to develop a set of land management practices that maximise the amount of carbon that remains in the soil
-the disadvantage is a forest planted to capture carbon might loss it to a forest fire

Question 10

milankovitch cycle-NATURAL IMPACT

Answer 10

• vostrok ice core data from Antartica suggest past temps change are from a variation in the earths orbit
• earths orbit is ellipsed-when the earth is closer to the sun, the temps increase- the shape is determined by the gravitational pull from other planets
• tilit= varies from 21-24 degrees over 41,000 years this increases summers and winters become colder
• the earths precession=the wobble of the earth is caused by gravitational pull of the sun and moon which effects timings of seasons