The Anthropocene Flashcards
What is the anthropocene?
A proposed geological epoch marking the point when human activity far outweighs natural impacts and variability.
What are the different kinds of geological times?
Epoch, period, era etc.
Describe the current geological age.
We are in the Holocene epoch, within the Quaternary period, within the Cenozoic era (this one being the longest).
What may be discovered in millions of years time locked away in rocks?
Plastic.
What do many people think the Anthropocene should replace?
The Holocene to become the new epoch.
What reason do people give for not assigning the Anthropocene a start date soon?
The impact of human activity will continue far into the future, so scientists in thousands of years time should designate the Anthropocene.
Why do some argue the Anthropocene should be dated as having started thousands of years ago?
Because as people began travelling beyond Africa large mammals living in other places were wiped out (didn’t know to fear people; those in Africa did).
How do some (not many) argue the earth should have entered the next glaciation now but human activity stopped it?
They argue agricultural activity beginning around the start of the Holocene released large amounts of greenhouse gases which prevented the next glaciation from occurring.
How do some propose the Anthropocene should be dated as having started in 1610AD?
Europeans arrived in Caribbean, native American population reduced due to new diseases/war/famine etc, reduced farming caused regeneration of forest. This caused a drip in CO2 emissions.
Why do some suggest the late 18th/early 19th century should be dated as the start of the Anthropocene?
Because it was the start of the industrial revolution.
How can carbon emissions in the atmosphere be used to determine how much fossil fuels people were burning?
Plants prefer to take up 12C (carbon) over 13C because it is easier for them to break down. When we burn fossil fuels made of plants carbon is released. When the carbon ratio has more 12C it indicates increased emissions from human activity.
How does nitrate from archives e.g. ice cores determine how much fossil fuels people were burning?
Plants take up more 14N than 15N. When records show the ratio had more 14N it is likely due to burning of fossil fuels due to human activity.
What is the most popular proposed date to mark the start of the Anthropocene and why?
1950 because various earth spheres (atmosphere, biosphere etc) became rapidly influenced by human activity from 1950 onwards.
