1 Atmospheric Changes: Climate Change and Air Pollution Atmosphere is the thin layer of gases that surrounds the Earth It supports life: Absorbs dangerous solar radiation Burns incoming meteors Transports and recycles water and other chemicals Drives Climate and Weather Chemical Composition of Atmosphere Major components Minor variable components
13
Embed
Atmospheric Changes: Climate Change and Air Pollution
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
1
Atmospheric Changes:
Climate Change and Air Pollution Atmosphere is the thin layer of gases that surrounds the Earth
It supports life:
Absorbs dangerous solar radiation
Burns incoming meteors
Transports and recycles water and other chemicals
Drives Climate and Weather
Chemical Composition of Atmosphere
Major components
Minor variable components
2
Although the atmosphere’s molecular
composition is largely similar
Certain characteristics change with altitude
Atmosphere is divided in layers
Ozone’s Distribution in the Atmosphere
Ozone layer
Temperature and other characteristics vary
between layers
Stratosphere:
most ozone (0.00004%) found here
ozone layer: filters UV rays
Troposphere:
ozone from human activities
causes health problems
Tropopause:
cap that prevents mixing between layers
3
Addressing the problem of Air Pollution
In 1971 the newly-formed Environmental
Protection Agency regulated 6 “criteria”
pollutants…
…even though no conclusive evidence
proved a cause/effect relationship
between the pollutants and human health.
What are the six criteria pollutants in
Air Pollution?
-particulate matter (particles or droplets)
and 5 chemicals:
-sulfur oxides
-carbon monoxide
-nitrogen oxides
-ground-level ozone
-lead
4
Addressing the problem of Air Pollution
In 1971, The EPA was following the
Precautionary, Though you are not 100% sure of what is causing a
problem, there is a big risk to “doing nothing.”
All six pollutants have since been shown
to be harmful.
The EPA now lists another 187 hazardous
air pollutants—including carbon dioxide!
5
Types of substances and their sources
Gases:
Oxides of carbon (CO, CO2)
Oxides of nitrogen (N2O, NOx)
Oxides of Sulfur (SO2)
VOC Tropospheric Ozone
Ozone depleting substances (ODS)
Aerosols:
Particulate matter (soot, dust and smoke)
Metals (lead and mercury)
Transformation: Pollution Changes in the air
Primary pollutants Secondary Pollutants
Emitted directly Form in the air
from source from primary pollutants
Note: Some chemicals can be considered primary and secondary
6
Impact of Air Pollutants • Change in Temperature:
Global warming (CO2 CH3 , HCFCs and N2O)
• Change in Water acidity:
Acid precipitation (SO2 and NOx)
• Depletion of stratospheric ozone:
ODP (chemicals with Bromide or Chloride atoms)
• Health problems:
Industrial smog SO, CO
Photochemical smog NO2 and VOC (volatile organic compounds)
Lead and Mercury
(deposited in water, enter food chain, accumulate in tissue)