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Holocene and Anthropocene
11,700 years to present
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Holocene From the end of the last ice age to the present.
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Europe 20,000 years ago All of northern Europe under mountains of ice
This locked much of the ocean’s water into ice and exposed large portions of the continental shelves It also caused the earth’s climates to be drier
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Land Bridges
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Sea Level Rise After the glaciers retreated, the sea levels rose 120 m from the last glacial maximum
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Temperature change over the past 10,000 years
Marcott et al. 2013
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Change in temperature over the past 11,000 years and its influence on human history
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Relationship between advent of humans and megafaunal extinctions
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Extinction rates since 1800
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What is the Anthropocene?
The argument that the earth is in a post Holocene epoch This new epoch is defined by actions and by-products of humanity. That is, it is a human-influenced age. Resisted by stratigraphers who claim that we should be able to detect a change in the geological record
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Evidence of the Anthropocene
Human activity has: Pushed extinction rates of animals and plants far above the long-term average. The Earth is on course to see 75% of species become extinct in the next few centuries if current trends continue. Increased levels of climate-warming CO2 in the atmosphere at the fastest rate for 66m years, with fossil-fuel burning pushing levels from 280 parts per million before the industrial revolution to 400ppm and rising today. Put so much plastic in our waterways and oceans that microplastic particles are now virtually ubiquitous, and plastics will likely leave identifiable fossil records for future generations to discover. Doubled the nitrogen and phosphorous in our soils in the past century with fertiliser use. This is likely to be the largest impact on the nitrogen cycle in 2.5bn years. Left a permanent layer of airborne particulates in sediment and glacial ice such as black carbon from fossil fuel burning.
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When did it begin? The beginning of the industrial revolution (~1800)
The atomic age (~1950) The dawn of agriculture (these dates occupy much of the Holocene Epoch) 11-8 KYA in the fertile crescent 9 KYA Yangtze and Yellow River basins 9-6 KYA New Guinea Highlands 5-4 KYA Central Mexico 5-4 KYA northern South America 5-4 KYA sub-Saharan Africa 4-3 KYA eastern North America
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Increase in CO2 almost entirely due to human action
CO2 added by volcanic action less than 1% of global industrial production (USGS 2007) CO2 sinks shrinking
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Arguments by Climate Change Deniers include:
Climate has changed before (4.3%) It is the sun (4.2%) It is not bad (3.9%) There is no consensus (3.2%) It is cooling (3.1%) Models are unreliable (2.9%) Temp record is unreliable (2.4%) Animals and plants can adapt (2.2%) It has not warmed since 1998 (2.0%) Antarctica is gaining ice (1.8%) Ice age predicted in the 70s (1.8%) CO2 lags temperature (1.8%) Climate sensitivity is low (1.7%) We are heading into an ice age (1.7%) Ocean acidification not serious (1.7%) Hockey stick is broken (1.7%) Climategate CRU conspiracy (1.6%) Hurricanes are not linked to CC (1.5%) Al Gore got it wrong (1.5%) Glaciers are growing (1.5%)
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Who is the DoDo?
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