Nats 1840 - Lecture 18

Nats 1840 - Lecture 18 - NATS 1840 Lecture 17 Modern...

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NATS 1840 Lecture 17 – Modern Agriculture and the Environment - Agriculture transformed significantly after the turn of the century - In the early 20 th century the gas powered tractor removed labor and horses from farm, halved horse use in a nation that had millions of horses in agriculture - Transfer away from horses allowed land used to feed them to grow crops for us, feeding an additional 16 million people - Harvester combines using steam and internal combustion harvested and threshed the grain - In the 1930’s rural America was electrified, allowing electrical refrigerators, pumps and lighting - Crossbreeding of plants has produced varieties that last longer, are resistant to pests, produce more, etc. - Certain varieties of crop, for example tomatoes, have been selectively bred for the machines that pick them - There has been some concern that we may be reducing biodiversity which is a natural safety system in case of disease or disaster - Pesticides, herbicides and chemical fertilizers became popular after the war, now the majority of farms use some combination of all three - The focus of your reading is the pesticide industry, which invests heavily in R+D in chemistry, it is a science-based industry Pesticides - 2.5 million tons of pesticides used each year worldwide, costing approximately 20 billion - 37% of all food and fibre crops are destroyed due to pests despite the use of pesticides - Without pesticides losses are estimated at 47%, with some crops being destroyed entirely - 10 fold increase in pesticide use between 1945 and 1989, losses due to insects doubled in this period to approximately 13% - Part of the reason for the high impact of pests has been the adoption of continuous production of crops, increased production leads to increased losses - Pesticides are evaluated based on their impact on crop returns, wider costs are not generally taken into consideration - Here we see the pattern of evaluating developments based on their impact on efficiency and production, rather than social and environmental costs Costs of Pesticide Use Human Health - estimated 1 million human pesticide poisonings and 20,000 deaths per year - a far larger number of pesticide related deaths occur in the developing world,
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Nats 1840 - Lecture 18 - NATS 1840 Lecture 17 Modern...

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