🌍 elss sg6 Flashcards
how are the carbon and water cycle linked in the cryosphere
positive feedback loop
higher temps = less water stored as ice as it melts = decreases albedo so more UV radiation absorbed = permafrost melts = co2 and methane released = more atmospheric co2 = higher temps
how are the carbon and water cycles linked in the biosphere
- organic matter = soil clumps together (hummus) so soil can hold more water
- too wet soil = less decomposition
- too dry soil = microorganisms die = no decomposition
- water deficit = less photosynthesis = less NPP = less transpiration = less organic matter in soil = less decomposition = less co2 atmosphere
how are the carbon and water cycles linked in the oceans
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oceans acidification
co2 dissolves into surface water, ph is too high so animals can’t survive, less phytoplankton = less co2 absorbed = more co2 in atmosphere - temps rise = warmer water so less co2 absorbed, less co2 removed from atmosphere by oceans
how are the water and carbon cycles linked in atmosphere
- more co2 in atmosphere = more ET = more precipitation
- co2 combines with water vapour = chemical weathering = carbon released into atmosphere
- water need to plants to photosynthesis = co2 removed from atmosphere
impact of long term climate change on water cycle
- increased evaporation = increased precipitation
- more overland flow = increased river discharge = higher flood risks
- more ice sheet melting so sea levels rise = exposed rock = plants grow = more ET & precipitation
impact of long term climate change on carbon cycle
- enhanced greenhouse effect
- permafrost thaws = carbon released & lower albedo
- higher risk of wildfires = carbon to atmosphere (combustion)
- more decomposition = more co2 in atmosphere
- ocean acidification due to more carbon in atmosphere
what are the 3 international agreements
Kyoto protocol 1997
Paris agreement
COP 26
strengths of Kyoto protocol
- collective emissions to be reduced by 2GT per year
- 175 countries signed treaty
- first agreement
- raised public awareness
weaknesses of Kyoto protocol
- USA who were responsible for 25% of emissions would not sign
- LIDCs and EDCs not involved
strengths of Paris agreement
- 195 countries
- aim to reduce global warming below 2*C
- developed nations to help EDCs and LIDCs with costs
weaknesses of Paris agreement
- no legal binds so could be ignored
- temperatures are still predicted to rise by 2.7*C
strengths of COP 26
- USA & China pledged to cooperate more
- 200 countries agreed to 1.5*C warming limit
- 100+ countries agreed to stop deforestation by 2030
- pledged to reduce coal emissions
- backing clean technologies
weaknesses of COP 26
- no legal binds
- scheme to cut methane emissions doesn’t include russia, china or india
how can afforestation protect the carbon cycle
- 15% of carbon emissions are caused by deforestation
- photosynthesis = less carbon in atmosphere
- expensive so can only be done on small scale so only has small impact
how can improved farming practices protect the carbon cycle
- 1/3 of carbon emissions comes from farming
- mulching leaves crop residue eg leaves to cover soil = less soil erosion
- zero tileage = no ploughing involved
- agroforestry = crops combined with tree planting
- improved animal feed = less methane released from animals
- means reduced co2 emissions but doesn’t compromise food production
- would have to be on bug scale
