Case Study → Changing Climates, The Amazon (Edexcel A-Level Geography): Revision Notes

Case Study → Changing Climates, The Amazon

Context	● The forest acts as a global and regional regulatorm pumping 20 bn metric tonnes of water into the atmosphere daily, 3 bn more than the River Amazon discharges to the ocean ● The forest's uniform humidity lowers atmospheric pressure, allowing moisture from the Atlantic ocean to reach further inland than areas w/out forest coverage ● Rain bearing winds travel W until deflected by the Andes and normally transport moisture S sto Buenos Aires and E to Sao Paulo
Change in Climate	● Since 1990, a more extreme cycle of drought and floods has developed in Amazonia, w/ a wetter rainy season, linked to shifts in the Inter-tropical convergence Zone) ● Rainfall has ↓ downwind of deforested areas, w/ Sae Paulo suffering a water crisis ● Severe droughts in 2005, 2010, 2015 and 2016 has increased stress which was already high due to decades of deforestation ○ 2005 drought damaged 30% of the forest ○ 2010 many areas still vulnerable, 50% of forest affected ■ During droughts, less CO2 absorbed and greater decomposition of dead biomass = increased CO2 emissions • approx 13 bn tonnes during 2005 & 2010 droughts)
Impacts	A Drier Amazon means that the rainforest is close to becoming a net carbon emitter rather than a major carbon sink

•                                                      Climate change Amazon regions*