Climate Change and Agriculture

Deforestation: video

• Deforestation is occurring by 6.4 million hectares per year, about .55% of the world’s tropical forests per year.
• Transfers 1.7 gigatons of carbon into the atmosphere every year (according to the IPCC).
• 96% of deforestation is done for agricultural purposes.

Carbon Stocks

• CARBON SINKS AND FLUXES….
• CARBON SINK = RESERVOIRS OF CARBON IN THE EARTH
• FLUXES = WHEN CARBON IS RELEASED INTO THE ATMOSPHERE
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Land Use:

Climate Change Effect on Crop Yields

• Benefits - Carbon Only: Disregarding other aspects of climate change, the IPCC expects crop yields would increase across species anywhere from 0 to20% with the projected increase of carbon in the atmosphere.
• Benefits - All Aspects:
  • US Cornbelt - all major crops will benefit
    • Especially winter wheat -- milder winters
  • Southern Plains
    • Alfalfa hay
• Detriments
  • Water stress and increased temperatures cancel out the aforementioned benefits.
  • Soybeans are expected to be especially affected, decreasing their yields byat least 20%
  • Altered soil moisture levels caused by water stress and higher temperatures can stunt the growth of plants’ roots and impede their nutrient acquisition abilities.

Increased Pest Activity

• Increased temperatures in North America have already led to earlier spring activity of insects, especially the mountain pine beetle.

Easier Spread of Disease Among Livestock

• Example Foot and Mouth Disease
  • 1924 outbreak of Foot and Mouth disease when some swine were fed bone-meal made in Argentina that was infected.
  • 109,000 farm animals and 22,000 deer had to be slaughtered.