carbon cycle, air pollution and the greenhouse effect

how does co2 in the air enter the carbon cycle

photosynthesis

how do animals get their carbon

eating plants

how to plants, animals and decomposers release co2 back into the atmosphere

respiration

how do plants and animals return carbon to the soil

• they die and decomposers break down their organic matter into carbon compounds

• animals excrete faeces which is also broken down by decomposers

how to decomposers break down the material

• they release enzymes which catalyse the breakdown of organic matter into smaller molecules

how do human activities release co2 back into the atmosphere

• burning fossil fuels

• burning animal and plant products (wood)

what do the carbon compounds in the soil make

fossil fuels

what is produced if fuels are burnt in a limited oxygen supply

carbon monoxide

where the most carbon monoxide produced from

car emissions

what are cars fitted with to convert carbon monoxide into carbon dioxide

catalytic converters

problems with acid rain (2)

• acidifies lakes and rivers which changes the pH and kills wildlife

• kills trees - damages leaves, produces toxic substances from the soil = trees cannot take up nutrients

impacts of climate change

• extreme weather

• rising sea levels

• flooding

• habitat loss

how are humans producing methane (2)

• rice growing and cattle - bacteria in the fields/cow stomach

• rotting plants

how are humans producing nitrous oxide (3)

• bacteria in soils and ocean

• fertilising soils

• vehicle engines

how are humans producing CFCs (2)

• aerosol sprays

• fridges