how much change occurs over time in the water and carbon cycle?

Question 1

global energy consumption %

Answer 1

Oil 37%
Natural gas 27%
Coal 23%

Question 2

how much CO2 is released annually?

Answer 2

10 billion tonnes

Question 3

anthropogenic carbon emissions affect what stores?

Answer 3

the size of the atmosphere, ocean + biosphere

Question 4

what is the driver of present day global warming?

Answer 4

the combustion of fossil fuels + the transfer of carbon from geological stores to the atmosphere + oceans

Question 5

what is the solution to these emissions?

Answer 5

to capture and store Co2

new tech of carbon sequestration is know as carbon capture + storage

Question 6

what happens during carbon capture + storage?

Answer 6

the Co2 is separated from power station emissions, then it is compressed + transported by pipeline to storage areas, then it is injected into porous rocks deep underground where it is stored permanently

Question 7

how much has atmospheric Co2 concentrated increased from 1750-2012?

Answer 7

280 -> 393

Question 8

in USA what % all Co2 are coal + gas fired stations?

Answer 8

40%

Question 9

what % is CCS likely to reduce emissions by?

Answer 9

80-90%

Question 10

why is the technology of CCS limited in effectiveness?

Answer 10

• involved big capital costs eg the Drax + Peterhead projects will cost at least £1 bill
• uses large amounts of energy - typically 20% of a power plant’s output is needed to separate the Co2 + compress it
• requires storage reservoirs with specific geological conditions

Question 11

what are diurnal changes?

Answer 11

changes that occur within 24 hour period

Question 12

what changes occur at night?

Answer 12

lower temp -> reduce evaporation + transpiration

Question 13

when does convectional precipitation take place?

Answer 13

daytime (when temps reach max), dependent on direct heating of the round surface by the sun

Question 14

how does carbon flow in the daytime?

Answer 14

CO2 flows from the atmosphere to vegetation

Question 15

how does carbon flow at night-time?

Answer 15

without sunlight, photosynthesis switches off + vegetation loses co2 to atmosphere
also observed with phytoplankton in the oceans

Question 16

how are seasons controlled?

Answer 16

variation in the intensity of solar radiation

Question 17

when does solar radiation peak in the UK?

Answer 17

mid June eg around 800 W/m2 where as in Dec 150 W/m2

Question 18

when is evapotranspiration highest + lowest?

Answer 18

highest = summer, lowest = winter

Question 19

why are river flows normally at their lowest in late summer?

Answer 19

large losses of precipitation to evapotranspiration + the exhaustion of soil moisture

Question 20

how are seasonal variations shown in the CC for month to month changes?

Answer 20

net primary productivity of vegetation

Question 21

when is there a net global flow of Co2 from atmosphere to biosphere?

Answer 21

Northern hemisphere summer - trees in full follages

• > causes atmosphere Co2 levels to fall by 2 ppm
• > at the end of summer as photosynthesis ends, the flow is reversed with natural decomposition releasing co2 back to the atmosphere

Question 22

what has a global impact with seasonal changes?

Answer 22

the concentration of continental land masses -> during growing season ecosystems eg the boreal + temperate forests extract huge amounts of Co2 from atmosphere

Question 23

what is the climate record like over last 1 mill years?

Answer 23

highly unstable
there has been four major glacial cycles - cold glacials followed by warmer interglacials, each cycle lasting around 100,000 yrs
200,000 yrs ago avg annual temps in British isles were 5C lower than today
during warm interglacials periods there were similar temps to today but on much longer timescales global temps have been even more extreme eg 250 mill years ago avg global temp reached 22C at least 7-8C higher than today

Question 24

what changes does the water cycle undergo in glacial periods?

Answer 24

• in glacials the sea level worldwide falls by 100-130 m -> ice sheets + glaciers expand to cover 1/3 of the continental landmass -> as ice sheets advance they destroy extensive tracts of forest + grass land = the area covered by vegetation + water stored in biosphere shrinks
• in the tropics, climates becomes drier + deserts + grasslands displace large areas of rainforest
• lower rates of evapotranspiration reduces exchanges of water between the atmosphere + the ocean, biosphere + soils
• freshwater stored as snow + ice
  SLOWS WC

Question 25

what changes does the carbon cycle undergo in glacial periods?

Answer 25

• reductions in co2 - it is possible that excess co2 finds its way from the atmosphere to the deep ocean
• changes in ocean circulation - bring nutrients to the surface to stimulate phytoplankton growth - when they die more carbon is stored in deep oceans
• carbon pool in vegetation shrinks as ice sheets advance + occupy large areas -> deserts expand, tundra replaces temperate forests -> land surface being buried by ice, carbon stored in soils means it won’t exchanged within the atmosphere
• NPP + total volume of carbon fixed in photosynthesis will decline
• slowing of carbon flux + smaller amounts of Co2 returned to the atmosphere

Question 26

impact of LT climate change on WC

Answer 26

• amount of evapotranspiration increases = more water vapour in atmosphere -> positive feedback of water vapour, greenhouse gas, further increases global temp, evaporation + precipitation
• increased precipitation in urban area where its built on floodplains + deforestation will increase floods
• water vapour = source of energy in atmosphere -> can lead to more extreme weather evens eg storms

Question 27

impact of LT climate change on CC

Answer 27

• increase in carbon stored in atmosphere, decreased in biosphere + oceans
• higher temps increase rates of decomposition + the rate of carbon transfer from biosphere + soil to atmosphere will increase
• in permafrost areas carbon is being released from frozen ground as temp rises
• wehre temps = so high that aridity increases, forests will be replaced by grasslands which reduces carbon store in woody vegetation