Agriculture

Refer to textbook page 106 to answer question 1 and 4.

You may refer to the DEFINITION of terms and words used in the textbook below to help you with your reading:

Cultivating
– prepare the land for use for planting crops

Tractor
– A heavy duty vehicle used to pull agriculture equipments (transport loads)

Inorganic
– Not deriving from living matter.

Fertilizer
– A chemical or natural substance added to soil to increase its fertility (ability to produce more crops)

Ploughed
– Turn over and loosen soil for planting of seeds.

Decomposition
– Process of rotting or decaying

Crops
– Cultivated plant that is grown on large scale for selling (e.g.: cereals, fruit and vegetables)

Livestock
– Animals raised for use and profit (e.g.: Cows, sheep, goat, chicken, etc.)

Manure
– Animal dung/waste

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Read the following text to help your group answer question 2, 3 and 5.

In 2004, about 14% of the world’s greenhouse gas comes from agricultural activities. Of which, 40% of the agricultural greenhouse gas emission comes from cattle farming and 10% from cultivation of rice.

In United States (2012), about 9% of the state’s greenhouse gas emission comes from agriculture sector and it has increase gradually by 19% since 1990. You may refer to the graph below and focus on the total greenhouse gas emission from US agriculture sector.

The main cause the increase in greenhouse gas emission from US agriculture was the release of methane from cattle farming and nitrous oxide from the use of inorganic fertilizers. Following after carbon dioxide, methane is the second most common greenhouse gas emitted, followed by nitrous oxide. Although both methane and nitrous oxide are released in a smaller amount as compared to carbon dioxide, they are much more effective in trapping heat than carbon dioxide! (Methane is 21 times more ‘heat-trapping’ than carbon dioxide while nitrous oxide is 310 times more effective).

These greenhouse gases absorbs infrared radiation (long-wave radiation) emitted from the earth’s surface and does not allow much of it to escape into space. With the increase in methane and nitrous oxide released by agricultural activities, the concentration of greenhouse gases in the atmosphere increase leading to enhanced greenhouse effect. Where the high concentration of greenhouse gases traps more heat in the atmosphere resulting to a rise in global temperature (global warming).

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Reference

Mark, J. (2012). Methane contribution to global warming is worse than you thought. Retrieved from http://www.alternet.org/environment/methanes-contribution-global-warming-worse-you-thought

United States Environmental Protection Agency. (2014). Agriculture sector emission. Retrieved from http://epa.gov/climatechange/ghgemissions/sources/agriculture.html

Upham, B. C. (2010). Nitrous oxide’s global warming impact no laughing matter. Retrieved from http://www.triplepundit.com/2010/04/nitrous-oxides-global-warming-impact-no-laughing-matter/