No creature larger than a small dog survived the KT eventGradualists still think it was the Deccan TrapsoHappened when India moved over the Reunion plumeoNo evidence of the creation of a catastrophic environment from thisChapter 20: Holocene Mass Extinction Going on now¼ may be extinct by 2125 and ¾ by 2200Only 1.8/10 million species are documentedThe problem isn’t the quantity of CO2we pump out, it’s the rate at which we do itThis extinction has been split into waves:o1. Spread of Modern HumansHalf the genera of large animals diedFirst extinctions occurred from overkillSome from invasive species brought to Hawaii/NZ by Stone Age farmerso2. Spread of EuropeansEuropean expansion and migrationE.g. Spaniards in the Caribbean Causes in order areOver exploitationHabitat destructionIntro of invasive species from home
o3. GlobalizationTropical animals are most at riskSo are amphibians Humans have cut down 40% of all forestsLoss of habitat is primary causeOverexploitationOverfishingSelling turtle shellsInvasion of Alien SpeciesGreatest effect on isolated species e.g. on islandsAsian long horn beetle Climate ChangeUpsets whole food chainPollution2ndlargest threat to amphibians DiseaseBlight eliminated chestnut treesThe only solution is education:oThe reduction of human population is essentialoImproved biotechnology is importantoNatural habitats must be preservedoChange our attitude towards natureThree scenarios to finalize this extinction:o1. Collapse of the Gulf StreamPart of the Thermohaline Circulation System If it collapses, temp drops 5-8 degreesPlants die, famine occurso2. Collapse of Amazon Rainforest
Trees absorb CO2If too much CO2 in air then it won’t rain as muchTemp will soar, strengthen greenhouse and animals dieo3. Methane Release from Sea FloorTrillions of tons beneath the ArcticCould be released if ocean warmsVery strong greenhouse gasCase of Golden ToadCase of Passenger Pigeon
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- Winter '20
- sea level, mass extinction, Extinction event, Cretaceous–Tertiary extinction event