Carbon cycle - Human Changes Flashcards
What is the % of anthropogenic carbon released from combustion?
90%
What is the 4 human causes of change?
Combustion of fossil fuels
Deforestation
Urbanisation
Farming and practices
Combustion equation:
hydrocarbon + o2 = h20 + co2
Which animal releases the most methane and co2 and why?
Beef cattle:
They ruminate their food and the microbes in it ferment the animal feed into a more easily digestible carbohydrate so methane is produced as a bi product (enteric fermentation)
How much methane is released from beef cattle in the USA per year?
5.5 million tonnes per year.
How does peat in farming practices affect carbon cycle?
Draining the peat lands for farming releases trapped methane inside.
How does artificial fertilisers affect carbon cycle and what is the name of the fertiliser?
Ammonia - needs a lot of heat to produce which means more combustion so therefore a lot of carbon dioxide released.
How does rice fields affect carbon cycle?
Bottom of rice paddies have these microbes called methanogens which are submerged and release methane under anaerobic conditions.
How does ploughing fields affect carbon cycle?
Open the soil the it allows the air to mix with the microbes which speeds up decomposition and increases the respiration of carbon into the atmosphere.
What % does rice contribute to global methane production?
20%
Causes for deforestation list all 5:
Agriculture
logging
urban spraw
overgrazing
wildfires
How does carbon move in a natural system compared to a deforestation one?
In the natural system when a tree dies it decomposes slowly over time and releases carbon slowly. In this time plants also grow which compensates for the carbon being released through decomposition.
How much carbon does trees absorb and release through respiration?
120 gigaton of co2
and 60 released
How much kg of carbon is released per 1kg of rice?
4
4 ways agriculture releases carbon?
ploughing, fertilisers,harvesting, rearing live stock
