6.9 risk of large scale carbon release requires responses from players

Question 1

6.9a what are the uncertainties over the future?

Answer 1

questions such as: degree of climate warming- how much warmer? are dependant on numerous factors…..

1. NATURAL FACTORS: the resilience of other carbon sinks and stores, what are their capacities? (oceans take a very long time to respond to changes in greenhouse gas concentrations)
2. HUMAN FACTORS:
   - rate of population growth
   - economic growth
   - technology… eg, harnessing of alternative energy sources, will we fully adopt low- carbon energies?
3. FEEDBACK MECHANISMS

Question 2

6.9a contribution of tundra (natural factor) to the uncertain future

Answer 2

• 50% of worlds soil carbon is stored in the tundra
  as temperatures rise, permafrost melts and trapped carbon is released into the atmosphere as CO2 and methane
• climate change is deepening active layer of soil which increases decomposition thus reducing soils capacity to act as a store/ sink
  POSITIVE FEEDBACK LOOP: climate change= increased temp= increased rate of decomposition= increased CO2 in atmosphere= warming temps

Question 3

6.9a tipping point definition

Answer 3

point at which small changes become significant enough to cause a larger more critical change that can be abrupt and transform a stable system irreversibly

a climate tipping point is a critical threshold!!!!

Question 4

6.9a feeback mechanisms (definition)

Answer 4

series of events which are triggered by an initial change
— POSITIVE feedback loops AMPLIFY the initial change and lead to a repetition of the cycle
— NEGATIVE feedback loops COUNTERACT the initial change normally leading to the conditions found before the initial change

scientists have identified several feedback mechanisms and tipping points that they believe would accelerate future climate change

Question 5

6.9a forest die back (IPCC identified tipping point)

Answer 5

drought in rainforest, trees may die. a tipping point could be reached when moisture can no longer be recycled due to too few trees to intake moisture which leads to more trees dying

in boreal forest ecosystems: drought stress may cause a collapse of boreal forests. tipping point reared when trees no longer absorb much CO2. since it cannot adapt, southern margins may turn into grasslands

Question 6

6.9a contribution of tropical rainforests (natural factor) to uncertain future

Answer 6

• tropical rainforests store 200 tonnes of carbon per hectare, palm oil plantation stores 30 tonnes of carbon per hectare
• logging can change a rainforest from a carbon sink to a carbon source (trunks/ stumps left behind decompose releasing CO2)

Question 7

6.9a alterations to thermohaline circulation (??? HELP MORE INFO REQUIRED textbook pages)

Answer 7

the melting of northern ice sheets releases large amounts of fresh water in green ideas which is less dense and has low salinity. this will disrupt the circulation of water affecting run=entourage of

Question 8

6.9b/c adaption vs mitigation

Answer 8

adaption= adopt new ways of doing in order to live with the likely outcomes of climate change
vs
mitigation= re- balance the carbon cycle and reduce any impact of climate change
( RESPOND VS PREVENT)

Question 9

6.9b examples of adaptation strategies

Answer 9

1. water conservation and management
2. resilient agricultural systems
3. land use planning/ flood risk management
4. solar radiation management

Question 10

6.9b water conservation and management

Answer 10

examples include:
- fewer resources used/ less groundwater abstraction
- change in attitudes
- recycling water (use of grey water)
- importing rather than growing water thirsty crops
- smart irrigation
—— requires promotion and enforcement by governments (see c/s Singapore!)

c/s Isreal (60% crops grown with grey water)

Question 11

6.9b resilient agricultural systems

Answer 11

benefits :)
- higher tech drought tolerant species help resistance to climate change
- low tech measures generate healthier soils ad may help sequestration and water storage!!!
- indoor farming generates a higher yield (unaffected by weather/ other enviro factors)

costs :(
- more expensive technology
- high costs from intensive/ indoor farming
- genetic modification is debated
- food insecurity adds pressure to switch back to previous methods

c/s!! USA/ Syria
growing crops using a no- tilling approach increasing yields, improving soil structure, water conservation and erosion control!!

Question 12

6.9b land use planning/ flood risk

Answer 12

land use zoning places building restrictions in vulnerable flood plains and low lying coats
- low cost approach and prevents further damage
however… abandoning high risk areas and resettling is often unfeasible (megacities eg Tokyo) and requires good governance

c/s football fields river Ouse

flood risk management traditionally uses hard engineering strategies

Question 13

6.9b solar radiation management

Answer 13

reflection of solar rays through space based reflectors…

:) could cool the earth within months and be relatively cheap compared to mitigation

however uncertainty over effectiveness as it is untried and untested

:( only reduce temps and not alter other effects of GHGs eg acidification

Question 14

6.9c examples of mitigation strategies

Answer 14

1. carbon taxation
2. renewable switching
3. energy efficiency
4. afforestation
5. carbon capture and storage

mitigation requires global scale agreement and national actions both of which have proved to be problematic

Question 15

6.9c the 2 key global agreements

Answer 15

1. Kyoto 1997
   192 countries signed
   aimed to cut GHG emissions by 5% by 2012
   ONLY applied to the most developed countries
   :( USA didn’t ratify the agreement and since the agreement more countries have developed
2. Paris 2015
   195 countries signed
   agreed to reduce GHG emissions to almost zero by 2065
   aimed to limit temperature increase to 1.5 degree increase
   pledged $100 billion a year to help poorer countries
   :( unrealistic targets, many did not co operate/ contribute