This should include (but doesn't) the manufacture and use of pesticides and fertilizers, fuel and oil for tractors, equipment, trucking and shipping, electricity for lighting, cooling, and heating, and
emissions of carbon
dioxide, methane, nitrous oxide and other
green house gases.
However, the number is probably closer to 25 - 30 % as they failed to include the «manufacture and use of pesticides and fertilizers, fuel and oil for tractors, equipment, trucking and shipping, electricity for lighting, cooling, and heating, and
emissions of carbon
dioxide, methane, nitrous oxide and other
green house gases» and «still doesn't include a large portion of the fuel, the synthetic nitrogen fertilizer, some of the nitrous oxide, all of the CFCs and bromines, and most of the transport» and methane
emissions.