Chapter 24 (Air Pollution) & Chapter 26 (Ozone Depletion), Chapter 23, 24, 25, 26
What are the two primary gases (%) in our atmosphere?
78% N 21%O
What months are CO2 concentrations highest in the atmosphere and why?
April and August. CO2 concentrations are highest in the spring and fall due to growing and harvesting that also occurs in those months
process by which CFCs (specifically chlorine) lead to the destruction of stratospheric ozone (know formula)
Destruction of stratospheric ozone: Cl + O3 → ClO + O2
sick building syndrome
EPA studies have linked various air pollutants found in buildings to a number of health effects (headaches, nausea, irritability, fatigue, depression) 1 in 5 buildings is considered "sick" Four most dangerous air pollutants in developed countries Tobacco smoke Formaldehyde Radioactive radon gas Small particles of various substances in emissions
ETS/Secondhand smoke
ETS "secondhand smoke" Passive smoker if exposed to ETS Most hazardous indoor pollutant Nonsmoking exposure to ETS: reduced airway functions comparable to 10 cig/day lung cancer/heart disease Several thousand chemicals as irritants: NOx, CO, hydrogen cyanide, 40 other carcinogens ETS Factors # of people smoking in the room Size of room Rate of ventilation
parts of your body that can be damaged by air pollution
-respiratory irritant (lung cancer) -irritation of the eyes
what are some sources of atmospheric methane?
Livestock farming (cows, sheeps, goats) Rice paddies (transplanted rice fields) Natural gas production
why acid deposition is a major problem & how to reduce it
acid deposition: process by which sulfuric and nitric acid particles leave the atmosphere in the form of gases and precipitation (acid rain occurs when pH is below 4.5) major problem because: acid rain dissolves stone monuments and bridge supports how to reduce it: since acid rain is caused mostly by SOx, with a significant contribution made by NOx *coal-burning electric power plants are the major source of SOx for acid rain, so less of that*
What are anthropogenic greenhouse gases? How do each of the following affect global warming? (Carbon Dioxide, Methane, CFC's, Nitrous Oxides)
anthropogenic: Describing effects or processes that are derived from human activities, as opposed to effects or processes that occur in the natural environment without human influences *Carbon dioxide (CO2).* A minor but very important component of the atmosphere, carbon dioxide is released through natural processes such as respiration and volcano eruptions and through human activities such as deforestation, land use changes, and burning fossil fuels. Humans have increased atmospheric CO2 concentration by more than a third since the Industrial Revolution began. This is the most important long-lived "forcing" of climate change. *Methane.* Methane is emitted during the production and transport of coal, natural gas, and oil. Methane emissions also result from livestock and other agricultural practices and by the decay of organic waste in municipal solid waste landfills.On a molecule-for-molecule basis, methane is a far more active greenhouse gas than carbon dioxide, but also one which is much less abundant in the atmosphere. *CFCs*: Synthetic compounds entirely of industrial origin used in a number of applications, but now largely regulated in production and release to the atmosphere by international agreement for their ability to contribute to destruction of the ozone layer. They are also greenhouse gases. *NOx*: Nitrous oxide is emitted during agricultural and industrial activities, as well as during combustion of fossil fuels and solid waste. In order, the most abundant greenhouse gases in Earth's atmosphere are: Water vapor Carbon dioxide Methane Nitrous oxide Ozone Chlorofluorocarbons (CFCs)
harmful effects of UVB radiation
environmental -interferes with photosynthesis -lower productivity, less food available to food web -lower crop yields human health -cataracts -skin cancers (ex: melanoma) -weakened immune systems
ozone (in troposhphere) environmental and health effects
environmental: -causes bleaching of plant tissue -makes plants sensitive, brown, damaged or die -cracks rubber and reduces durability health: -aggravates asthma -causes injury to cells in respiratory system -causes eye irritation
Describe the chemical formation/decomposition of ozone in the stratosphere
formation: VOC + NOx + heat + sunlight = ozone O + O2 → O3 (oxygen molecule reacts with an oxygen atom to form ozone) decomposition: O3 + UV → O2 + O (ozone absorbs UV radiation, producing an oxygen molecule and an oxygen atoms)
formation & impact of ozone and nitrogen dioxides
formation: ozone→ VOC (volatile organic compounds) + NOx + heat + sunlight = ozone - VOC & NOx come from cars, power plants, and industrial facilities nitrogen oxides→ mostly from automobile engines and coal burning power/industrial plants or agricultural practices impact on human health & the environment: ozone→ bad in the troposphere; major ingredient of photochemical smog nitrogen oxides→ smog, acid rain, global warming
human activity that leads to the formation of tropospheric ozone and why ozone peaks in the daytime
human activity: exhaust fumes from cars -peaks in afternoon after the sun has time to fully react with exhaust fumes from cars (and sunlight is necessary for the reaction)
synergistic effect
multiplicative responses to 2+ pollutants (smoking)
Which age groups of humans are most affected by high air pollution levels?
old people with impaired health and children (because of activity level and developing lungs)
asbestos
source: fireproofing, insulation, vinyl floor, and cement products; vehicle brake linings Possible health effects: skin irritation, lung cancer
CO2
source: motor vehicles, gas appliances, smoking possible health effects: dizziness, headaches, nausea
CO
source: motor vehicles, kerosene and gas space heaters, gas and wood stoves, fireplaces; smoking Possible health effects: dizziness, headaches, nausea, death
sulfur dioxide
sources: coal and oil combustion, kerosene space heaters, outside air possible health effects: respiratory and mucous irritant
formaldehyde
sources: foam insulation, plywood, particleboard, ceiling tile, paneling, and other construction materials possible health effects: skin irritant, carcinogen
ozone
sources: photocopying machines, electrostatic air cleaners, outdoor air possible health effects: respiratory irritant, causes fatigue
volatile organics
sources: smoking, cooking, solvents, paints, varnishes, cleaning sprays, carpets, furniture, draperies, clothing possible health effects: possible carcinogens
radon
sources: soil gas that enters buildings, construction materials, groundwater possible health effects: lung cancer
how to control nitrogen oxides and sulfur dioxide
sulfur dioxide: stop using coal-based power, stop refining oil (sulfur appears in coal and oil) nitrogen oxides: use less gasoline or turn to green transportation, adopt better agricultural practices, burn less coal
half life
#HL = time/the given half life) A = Ax/(2)^(#HL)
how is photochemical smog produced?
photochemical smog ("brown haze") is produced when nitrous oxides and volatile organic compounds react with sunlight and form other secondary pollutants such as ozone VOCs + NOx + heat + sunlight = smog (as well as ozone) *smog levels are highest in higher temperatures/with more sunlight*
Describe methods used by scientists to study Earth's past climate
*Ice Core Data:* Trapped bubbles show atmospheric composition, greenhouse gas concentration, temperature trends, snowfall, solar activity, and frequency of fires *Proxy Indicators:* Types of indirect evidence that serve as substitutes for direct measurements. Ice caps, ice sheets, and glaciers; tree rings; cores in sediment; and coral reefs *Sediments* on land and in water can show patterns of animal and plant growth and allow deduction of climate conditions *Tree rings* obtained from logs or cores can show seasonal variability of climate *Paleo Proxy Record*: Climate data that can be gathered from a ¨proxy¨, such as from plant fossils and pollen distribution patterns, from which we reconstruct the history vegetation *The Historical Record*: Written records, stories, and even paintings can offer clues to historical climate conditions *Instrumental Record*: Weather data can be collected with such instruments thermometers, barometers, hygrometers (humidity), and anemometers (wind speed). Data recorded over time helps give clearer pictures of atmospheric trends *Carbon-14*: is an isotope found in all living creatures and the rate of its decay can be used to date plants and animal remains. Its amount increases in the atmosphere in periods of high solar activity, and can be matched with other data to deduce patterns of solar output
Name and explain the two major categories/sources of air pollution. Give examples of each.
*air pollutants are either from mobile or stationary sources* *Mobile sources*→ derive from transportation ex: CO2 from cars *Stationary sources*→ point sources, fugitive sources or area sources -point sources: a single identifiable source of pollution (ex: power plant) -fugitive sources: generate air pollutants from open areas exposed to wind (ex: dust from construction site) -area sources: defined areas (ex: urban community or an industrial complex)
Name at least 6 symptoms of exposure to indoor air pollution.
-Chemical pollutants may cause nosebleeds, chronic sinus infections, headaches, and sense irritations -More serious problems include a loss of balance or memory, chronic fatigue, difficulty in speaking, and allergic reactions
Clean Air Amendments of 1990
-Comprehensive regulations enacted by U.S congress that address acid rain, toxic emissions, ozone depletion and automobile exhaust -Total # of pollution allowed is divided into permits: this provides economic incentive for using clean technologies
Montreal Protocol (1987)
-Eliminated CFCs by half and eventual phased them out *U.S. stopped production of CFCs by 1999* -Production sustainably reduced; significant improvements should be evident by 2050
six criteria pollutants responsible for most air pollution
-Ozone: made by a chemical reaction → VOC (volatile organic compounds) + NOx + heat + sunlight = ozone → VOC & NOx come from cars, power plants, and industrial facilities *effects:* bad in the troposphere; major ingredient of photochemical smog -Sulfur dioxide: ⅓ comes from natural sources (sulfur cycle), ⅔ from human sources (combustion of sulfur-containing coal in power and industrial plants, oil refining and smelting of sulfide ores) *effects:* contributes to acid rain as sulfuric acid, causes breathing problems and bronchitis -Nitrogen oxides: mostly from automobile engines and coal burning power/industrial plants or agricultural practices *effects:* smog, acid rain, global warming -Carbon monoxide: sources are vehicle exhaust, forest fires, smoke stacks of fossil fuel burning power plants, tobacco smoke *effects:* long term exposure can lead to heart attacks and aggravate lung diseases; at high levels CO can cause headache, nausea, confusion, collapse, coma and death -Particulate matter: natural sources (dust, wildfires, sea salt) anthropogenic sources (coal burning power and industrial plants, motor vehicles, road construction) *effects:* causes lung cancer & respiratory diseases -Lead (Pb): important constituent of automobile batteries, gasoline, and paints (has been removed from gasoline and most products) *effects:* causes disorders and developmental problems in children, brain damage
Draw and explain the development of atmospheric inversions at the base of mountain ranges and in between mountains. How does this inversion enhance pollution issues in cities?
-in temperature inversions, cold air sinks to the valley floor or base of the mountains and becomes trapped there -pollutants (dust, smoke, vehicle emissions) are trapped close to the ground by the warm layer of air above -warm air layer acts like a lid and prevents pollutants from rising and dispersing -can cause medical problems for people with respiratory ailments and irritate the eyes, noses and throats of others
environmental effects of ozone depletion
-increased acid deposition and photochemical smog -while in atmosphere, CFCs act as greenhouse gases *CFCs are responsible for most ozone depletion* -reduced yields for some crops
how to reduce risk of skin cancer from UV exposure
-limit time in the sun (avoid 10am-4pm) -use sunscreen with an SPF of at least 15 -avoid tanning salons -when in the sun, wear clothing and sunglasses that protect against UV-A and UV-B radiation
primary vs. secondary pollutants
-primary pollutants→ emitted directly ex: CO -secondary pollutants→ produced through reactions among primary pollutants and normal atmospheric compounds ex: NOx (multiple nitrogen oxide compounds) or O3 (ozone)
Draw a diagram showing the production of radon gas and how it can enter your home. Describe 5 ways that you can help eliminate the concentration of radon in your home.
1) *Gas Permeable layer:* A layer beneath the flooring system to allow soil to move freely underneath the house 2) *Plastic Sheeting:* Plastic sheeting is placed on top of the permeable layer to prevent the soil gas from entering the home 3) *Sealing and Caulking:* Opening in the concrete foundation floor are placed to reduce soil gas entry into the home 4) *Vent Pipe:* A 3- or 4- inch PVC pipe runs from the gas permeable layer through the house to the roof to safely vent radon above the house 5) *Junction Box:* an electrical junction box is installed if an electric venting fan is needed
four issues/strategies to deal with CFC-induced ozone depletion
1) Montreal Protocol 1987 Eliminate CFCs by half and eventual phase out U.S. stopped production of CFCs by 1999 Production sustainably reduced; significant improvements should be evident by 2050 2) Substitutes for CFCs HFCs- hydrofluorocarbons-greenhouse gas 10,000 times more potent than a molecule of CO2 3) Short-Term Adaptation to Ozone Depletion Learning to live with higher levels of UV radiation 4) collect CFCs and reuse them
sources of pollution in your home or office
1) heating, ventilation, and air conditioning systems 2) restrooms 3) furniture and carpets 4) coffee machines, fax machines, computers, and printers 5) pesticides can contaminate buildings 6) fresh air intake that is poorly located (ex near a loading dock) can bring in air pollutants 7) smoke/secondhand smoke 8) remodeling, painting, etc (chemicals/fumes may enter through heating/ventilation system) 9) cleaning products and solvents 10) people can increase CO2 leveks 11) loading docks can be sources of organics from garbage containers, of particulates, and of carbon monoxide from vehicles 12) radon gas seeps into building 13) Dust mites + molds live in carpets/other indoor places 14) pollen can come from indoor and outdoor sources
Explain how your heating and cooling systems can be related to indoor air pollution levels.
Effectiveness of unit depends on: Proper design of the equipment relative to the building Proper installation Correct maintenance and operating procedures Indoor air pollution may result if any one of these factors concentrates pollutants from the many possible sources. If filters become contaminated with fungi, bacteria, or other potentially infectious agents, serious problems can result. *High humidity may facilitate growth of molds; low humidity could be a source of discomfort*
Explain the significance of the Kyoto Protocol to global warming.
Legally binding emission limits were discussed Nations that agreed to cut emissions were far below the reductions suggested by scientist US eventually agreed to cut emissions to 7% below 1990 levels (leading scientists recommend cuts 60-80% below) Become a formal treaty in 2006 A cut in emissions slow global warming
negative feedback loop
Negative feedback (stabilizing) Global warming produces more algae and land plants which would then absorb carbon dioxide, eventually producing a cooling effect (Increase in carbon dioxide concentrations stimulates plant growth) As global temperature increases, evaporation increases which leads to more water vapor in the atmosphere and thus more clouds to reflects more sunlight which eventually cools the surface.
ozone blocks UV light and then is broken down into...
O2 + O ozone absorbs UV radiation, producing an oxygen molecule and an oxygen atoms
positive feedback loop
Positive feedback (accelerates) Warms temps lead to increased evaporation but instead of clouds forming remain as water vapor (natural greenhouse gas) Polar ice caps melting which would reduce the amount of solar energy reflected from Earth (albedo)
gases that increase acidity of rainfall
SOx & NOx (but mostly SOx) sulfur oxides and nitrogen oxides
Name and explain some likely consequences of global warming as they relate to storms, food supply, sea levels, ice caps, and biosphere.
Sea level rise Increase in coastal flooding, saltwater intrusion Permafrost occurs in soils found beneath 24% of the exposed land in the northern hemisphere. Reservoir of carbon... carbon locked up is 50-60x the amount emitted as CO2 emitted each year from burning fossils fuels! Increased Ocean acidification - CO2 absorbed by ocean reacts with water to produce carbonic acid H2CO3) Changes in Biological Diversity (extinction) IPCC- approximately 30% of land based plant and animal species would dissapear if the average global temperature change reaches 2.7-4.5 degrees F. Glaciers and Antarctic Ice Cap: Many more glaciers in the world are retreating than advancing. decrease in agricultural production Food supply: Globally, agriculture production is likely to increase in some regions and decline in others. A climate shift could have serious negative effects on mid-latitude food production. In addition, lands in the southern part of the Northern Hemisphere may become more arid. soil moisture relationships will change. storms: Changes in climate not only affect average temperatures, but also extreme temperatures, increasing the likelihood of weather-related natural disasters.
How have carbon dioxide levels changed from the late 1950's to today. Why do scientists believe this trend has occurred?
Since the first measurements in 1958, CO2 has risen from 313 ppm to over 400 ppm. A large part of the increase comes from human activities, especially from the burning of fossil fuels like coal, oil and natural gas. (deforestation, cars)
Describe the ocean conveyor belt and explain how it may drive the global climate system.
This loop consists of both warm, shallow water and cold, deep water. responsible for warming western Europe and may affect global climate. Ocean currents act much like a conveyer belt, transporting warm water and precipitation from the equator toward the poles and cold water from the poles back to the tropics.
Name and describe the four layers of the atmosphere and explain how temperature changes as you rise through each layer.
Troposphere, Stratosphere, Mesosphere, and Thermosphere Troposphere: As altitude increases, temperature falls. Stratosphere: As altitude increases, temperature rises. Mesosphere: As altitude increases, temperature falls. Thermosphere: As altitude increase, temperature rises.
characteristics of the different types of ultraviolet radiation (α, β, γ)
UVA (alpha): -longest wavelength -least energetic radiation -is transmitted to earth UVB (beta): -middle wavelength -MOST HARMFUL FORM OF RADIATION, damages living cells -most is absorbed by ozone layer; depletion of ozone layer will lead to increased UVB on earth UVC (gamma): -shortest wavelength -strongly absorbed in atmosphere -negligible UVC reaches earth
Which natural greenhouse gas is responsible for about 85% of the natural greenhouse effect?
Water Vapor
