biological consequences of air pollution Flashcards
4.12
what is the cause of sulphur dioxide?
combustion of fossil fuels that contain sulphur impurities create sulphur dioxide
what is the cause of nitrogen oxides?
produced during fossil fuel combustion- these gases react with oxygen and dissolve in rainwater to produce dilute sulphuric acid and nitric acid, which leads to acid rain
how does acid rain affect biodiversity?
can damage the leaves, buds, flowers and roots of trees and other plants
rivers and lakes too acidic- death of certain aquatic organisms
leaching of minerals that are toxic to fish, such as alluminium into lakes
the sun’s radiation is reflected by the earth’s atmosphere- but some is not all radiated…
some passes through and is absorbed by the earth’s surface- this warms the earth which then emits infrared radiation
what happens to the IR radiation that does not pass through the atmosphere into space?
some gases in the atmosphere absorb the IR radiation, preventing it from escaping back into space- leads to more energy being held by the atmosphere, heating it
what are the gases that absorb the IR radiation?
water vapour, carbon dioxide, methane, nitrous oxides and CFC’s
what is the cause of CO2?
burning fossil fuels
slash and burn forest clearance
what is the source of methane?
generated by bacteria in anaerobic conditions e.g.:
cattle produce methane from the anaerobic activity of bacteria in their gut- comes out from their mouths
bacteria in waterlogged paddy fields for rice cultivation give off methane
what is the source of nitrous oxides?
burning fossil fuels
what were CFC’s blamed for?
the hole in the ozone layer
until the 1990’s what were CFC’s used as?
a solvent for aerosols such as deodorants
also used in fridges and freezers
what is a greenhouse gas?
a gas that absorbs infrared radiation from the sun so that it remains trapped in the earth’s atmosphere
