L5- precolonial land use Flashcards
how have humans impacted the earth system pre and post 1492
connecting ancient history with modern globalisation
- 1492 CE= european colonisation of the americas changed how people impacted the world
before 1492- damaging impacts of societies on the environment and the exploitation of other people were local or regional in scope and scale
after 1942- these impacts became globalised via an economic system that embodied resource extraction and the exploitation of people
what are the origins of agriculture
agriculture arose as the outcome of an evolutionary process and was enabled by climate change
- agriculture began in multiple independent regions, archaeology shows a slow transition to agriculture not a revolution
-12,500yrs ago- first cultivation of wild plants
9,500 yrs ago- first agriculture economies
5,000yrs ago- first states cities and writing
until 1600AD- most societies on earth were not purely agricultural
what early agriculture good for people
no it was pretty bad for health
neolithic evidence from human skelatons shows-
-less work, greater fertility, higher population density
- more infectious diseases and serious deficiencies
what does ethnography show
shows that modern hunter gathers choose to forage
- hunter gatherers work 4-10 hrs a day (foraging, food processing, toolmaking, childcare). leisure tim
- choose mix of hunting, foraging, pastoralism, cultivation
why did people stop gathering to rely on farming
positive mutliplier effect ish
why did societies get “locked in” to agriculture
1- wild habitats destroyed through deforestation with increasing agriculture, very hard to go back after natural habitat destroyed, carrying capacity of landscape reduced
2- domesticated species became more productive then wild ones
how did climate encourage agriculture
deglaciation also allowed agriculture to begin, agriculture coincides with changes in climate and co2
-as climate warms ice melts leaving more fertile land
- glacial to interglacial co2, rise drives 50% increase in C3 crop yield, crop yield of C4 plant increase slightly
- greater climatic variation during Pleistocene then Holocene, less reliability
was agriculture impossible during the Pleistocene
people had the necessary technology and intellect, but
- low and unpredictable plant productivity made it impossible to specialise on a narrow range of crops
- sedentary agriculture-> high crop losses, famine
-nomadic gathering-> broad spectrum of resources, complementarity, buffers against change
did climate change take off the handbreak
- deglaciation -> CO2, climate variability, rainfall
high/predictable plant productivity in the Holocene allowed specialisation on a narrow range of species
-positive feedback between sedentism, intensification of food production and population
what is link between population and agriculture
population densities in modern foraging societies vary with environment, geography and culture
apply model to archaeological past to test alternative hypothesises about the situation in which agriculture began
model shows that population growth under improving environmental conditions preceded the orgins of agriculture in every geographic centre
against common belief, agriculture began during times of plenty where populations grew, agriculture no the result of times of hardship
did the spread of agriculture change climate
agricultural expansion has an ancient history, expansion of agriculture from centres of origin such as middle east into Europe
early anthropocene hypothesis - people have had impacts on climate for 10,000 yrs or so (not just looking at idustrialisation)
- co2 emissions from deforestation for agriculture, ch4 emissions from livestock and rice paddies
- deforestation for ancient agricutlure is a plausible explantion for part of the co2 increase - ice cores show CO2 rising from 7-1TYA thousand yrs ago
carbon cycle modelling and data suggest less then half of this is caused by deforestation 7-3TYA
deforestation is plausible explanation from 3 TYA
paddy rice and livestock were likely sources of agricultual methane from 5,000 yrs ago, but tropical wetland emissions are sufficient to account for Holocene CH4 record
should the focus on the behavioural cause that than the effects of human environmental modifications
should the anthropocene begin “ when evidence of signif human capacity for ecosystem engineering or niche construction behaviours first appear in archaeological record on global scale”
- human activities intended to modify ecosystems by increasing abundance of economically important species
-these appear with origins of agriculture at pleistocene-holocene boundary- i.e. replace holocene with anthropocene
why does this matter?
accepting an ancient origin for the Anthropocene “normalises” global environment change
- attribution, agriculture was historically important but the climate crisis arises largely from fossil fuel use, especially linked to globalised consumption since 1950
what is the caveat to how historical and traditional management practises created valuable landscapes and hold lessons for today
BUT important not to romanticise past society
- fossil record shows polynesian colonisation of pacific islands coincided with extinctions of birds
- population sizes of 4 million species stable for 4,000 yrs before Polynesian people first settled
not perfect
why are lessons from the past important for future
agricultural methods- diverse crops, dark soil, raised fields- useful today in contexts where mechanisations and access to energy and capital may be limited
traditional land management practises- especially where colonial mismangement has led to problems, fire in austrialia
