Where all the weather happens (Greenhouse gasses stays here; H2O, CO2, CH4, N2O)
Highest gas density (75%-80% of Earth’s air mass; 78% N2 and 21% O2)
Supports life
Stratosphere (17-48 km above surface)
Ozone Layer (Filters 95% of harmful UV radiation)
Layers of the atmosphere
Troposphere
Stratosphere
Mesosphere
Thermosphere
Natural Sources -
Wind blown dust (soil erosion)
wildfires
volcanic eruption pollutants
volatile organic compounds released by plants
Human Sources - Industrialized and Urban pollutants
Industrial Smog
Primarily from burning Coal
Consists of SO2, H2SO4, and solid particulates
Combustion of oil and coal forms CO, CO2, and Soot
Common in industrialized areas
Photochemical Smog
Caused by emissions from motor vehicles, industrial facilities, and power plants
Formed under the influence of the sun’s UV radiation
VOCs + Nitrogen Oxides + Heat + Sunlight yields:
Ground level O3, Aldehydes, and other secondary pollutants
Primary pollutants - Emitted directly to the atmosphere
Secondary pollutants - formed from primary pollutants reaction with air
Stationary Sources - power plants, industrial facility
Mobile Sources - Motor vehicles
Types of indoor air pollutants
Less developed countries:
Biofuel that produces soot, smoke, an CO
Prominent use of biofuel indoor for heating and cooking
Coal, wood, dung, charcoal, crop residue
Types of indoor air pollutants
More developed countries:
Chemical use for cleaning and building
Smoking
Radon-222 gas
Indoor Air Pollution Health hazards
Air pollution is about 2-5 times higher inside US houses and buildings than outdoors (could go up to 100x)
Pollution inside cars can go up to 18x higher than outside
Most people in more developed urban areas spend 70%+ of their time indoors or in their vehicles
Radon-222
Radon-222 from underground deposits
Radon-222 undergoes radioactive decay into Polonium-210 which can expose lung tissues to radiation
Radon tests for detection
Acid Deposition
Cause and Sources
Human generated Sulfur Oxides and Nitrogen Oxides gets into the atmosphere
Wet Deposition: Acid Rain, snow, fog, or cloud vapor
Dry Deposition: Acidic particulates
Ammonia in the atmosphere and some soil particles neutralizes acids which in turn produces Sulfates and Nitrates
Remains in the atmosphere for 2-14 days
Buffers - keeps the pH stable
Wet Deposition: Acid Rain, snow, fog, or cloud vapor
Dry Deposition: Acidic particulates
Buffers - keep the pH stable
Acid Deposition Effect
Respiratory disorder
Releases toxic metals from soil → biomagnification
Lowers pH in aquatic systems
Leeches soil nutrients and minerals
Damages forests
Damages stoneworks
Clean Air Act 1970/77/90 created regulations and enforced by states and cities
EPA established air quality standards for six outdoor air pollutants (CO, NO2, SO2, Suspended particulate matter, Ground level O3, Lead)
National emission standards for hazardous air pollutants (HAP)
188 hazardous air pollutants
The Toxics Release Inventory (TRI) is a resource for learning about toxic chemical releases and pollution prevention activities reported by industrial and federal facilities
New US regulation limits CO2 emissions from coal-fired power plants
New air quality standards for China ban high-sulfur, high-ash content coal in major cities
Air Pollution Treaties
Kyoto Protocol
1997: Treaty to slow climate change
USA did not sign
2014: USA and China agreed to cap carbon emissions within 15-20 years
2015: Paris Meeting
Countries pledged to meet certain goals
No financial assistance for poor countries to reach goal
Countries are not legally bound to comply (unenforceable)
Long term VS Short term
ChloroFluoroCarbons (CFC): Ozone depleting chemical
Ozone Depletion
Thinning of layers in Antarctica and the Arctics
ChloroFluoroCarbons (CFC): Ozone depleting chemical
Takes 11-20 years to reach stratosphere so there will be a long delay between banning CFC and the recovery of the ozone
Will take 60 years to recover back to 1980s level
Copenhagen Amendment
Accelerated phase-out of CFCs
Montreal Protocol
Cut emissions of CFCs
Climate Change Natural Factors
Volcano eruptions
Solar input
Earth’s orbit and tilt
global air circulation pattern
changes in albedo
greenhouse gas
ocean currents
Climate Change Human Factors
Fossil fuel use, deforestation, agriculture
Basically more Carbon footprint and lesser carbon sink
Climate Change
Between 1906 and 2016, earth’s temperature rose by 0.94°C
10 warmest years on record since 1861 have taken place since 2005
Arctic ice has been shrinking since 1979
Glaciers are melting
Permafrost is melting, rising sea levels reducing coast
Carbon dioxide and methane levels have risen sharply
Terrestrial organisms have migrated towards poles and up mountains where it is cooler
Carbon Footprint -the total amount of greenhouse gasses (including carbon dioxide and methane) that are generated by our actions.
Carbon Sink - anything that absorbs more carbon from the atmosphere than it releases – for example, plants, the ocean and soil.
Carbon Sequestration -the process of capturing and storing atmospheric carbon dioxide -1 method of reducing the amount of carbon dioxide in the atmosphere with the goal of reducing global climate change.
Carbon Neutral - the balance between emitting carbon and absorbing carbon emissions from carbon sinks. Or simply, eliminate all carbon emissions altogether. Ex: Costa Rica - Carbon neutral by 2030
Carbon source is anything that releases more carbon into the atmosphere than it absorbs – for example, the burning of fossil fuels or volcanic eruptions
Feedback Loop
In climate change, a feedback loop is something that speeds up or slows down a warming trend.
A positive feedback accelerates a temperature rise, whereas a negative feedback slows it down.
Albedo
Albedo is the fraction of light that a surface reflects.
The albedo of Earth's surface (atmosphere, ocean, land surfaces) determines how much incoming solar energy, or light, is immediately reflected back to space.