The evolution of the atmosphere
The early earth's atmosphere was thought to contain? O2
little or no oxygen
ee atmosphere thought to contain? CO2
a large amount of CO2
ee atmosphere thought to contain? H2O
water vapour
ee atmosphere thought to contain? og
small amounts of other gases
define carbon footprint
measure of the amount of CO2 emitted into the atmosphere by a particular activity by a particular individual or organisation over its lifetime
why did the volume of wv decrease and what did it form?
the temp dropped and the wv condensed and formed oceans
how did condenstion of wv lead to less CO2
the CO2 dissolved in the oceans as carbon precipitates sediments
what organisims evolved about 2.7bn years ago
algae and green plants
how did primitive plants affect CO2 levels in atmo?
the growth of primitive plants used carbon dioxide and released oxygen by photosynthesis and thus the amount of oxygen in atmo increased and CO2 decreased
nitrogen percentage in atmo
78.1
oxygen percentage in atmo
20.9
argon/trace gases percentage in atmo
0.96
carbon dioxide percentage in atmo
0.04
dsecribe chemical test for oxygen
a glowing splint, re-lights when introduced to a test tube of oxygen
describe chemical test for carbon dioxide
when carbon dioxide is passed through limewater, the limewater turns milky
whats the greenhouse effect?
the sun emits electromagnetic radiation, the earth's surface emits longer wavelength radiation, most of the radiation is reflected back into space, greenhouse gases absorb the radiation which is then re-emitted back to earth, warming it
potential effects on climate of increased levels of carbon dioxide and methan generated by human activity
rising temperatures, extreme weather events, sea-level rise
major sources of carbon monoxide
vehicles, industrial processes, and incomplete combustion of fuels
major sources of particulates
combustion, industrial processes, and natural sources like dust and wildfires
carbon monoxide and particulate issues humans
respiratory problems, cardiovascular issues, and increased risk of cancer
carbon monoxide and particulate issues humans environment
contributes to the formation of ground-level ozone (smog) and can affect plant growth and ecosystems, can reduce visibility, contribute to acid rain, and damage ecosystems
define acid rain
rainfall made so acidic by atmospheric pollution that it causes environmental harm, chiefly to forests and lakes
what causes acid rain
sulfur dioxide and oxides of nitrogen
problems of increased sulfur dioxide
respiratory issues like coughing and wheezing, exacerbating conditions like asthma and bronchitis, and contributing to acid rain, which damages ecosystems and infrastructure
problems of increased oxides of nitrogen
respiratory irritation, increased vulnerability to infections, and contributing to smog and acid rain
importance of scientists in helping to resolve the problems of acid rain?
identifying its causes, monitoring its effects, and developing solutions, ultimately leading to policy changes and environmental improvements