Chemicals
We've derived great benefits from the manipulation of chemicals - along with some serious problems.
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What follows is a sampling of a few infamous chemicals, but there are many more (see bottom of page). ​​​​
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Carbon Dioxide - CO2
Carbon dioxide (CO2)
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is the best known and
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longest lasting (centuries!)
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of the greenhouse gases,
which cause planetary
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warming.
“The increase in atmospheric concentrations of CO2 and other ... gases ...
increase the absorption and emission of infrared radiation by the atmosphere.
This has led to a rise in average global temperature and ocean acidification.”​​
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Methane - CH4
"Methane [CH4] is a super-pollutant."
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Methane dissapates more quickly than CO2.
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While active however, it's a powerful component of the greenhouse problem.
Enteric Fermentation
is (mostly) from cow burps.
US "methane emissions ... are worse than ... estimated, a [2024] study has found."
"Methane that escapes into the atmosphere
can wreak havoc on public health ... ​​
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Methane is responsible for 25 percent of ... human-produced warming."
In the US. alone, 13 million tons
leak into the atmosphere - every year.
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Refrigerant Gases - CFCs, HCFCs, & HFCs
​Coolant chemicals were developed in the 20th century for air conditioners, refrigerators, etc. ​
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The most widely used types of refrigerant gases have been: ​​
- chlorofluorocarbons (CFCs)
- hydrochlorofluorocarbons (HCFCs) and
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- hydrofluorocarbons (HFCs) ​​​​​
Scientists found that CFCs cause "damage to the ozone layer that protects [us] from ultraviolet radiation."
These 1980's studies "led to the ... phase out of CFCs and HCFCs,"
which is doubly good because: “CFC-12 [is] … an extraordinarily potent [& decades-long] greenhouse gas.” ​​​
"The ... phasing out ... of these [CFCs and HCFCs] harmful substances ...
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is leading to a [gradual] recovery of the ozone layer."
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​ Thank goodness! Except that the new coolants (HFCs) also create pollution.
"Hydrofluorocarbons (HFCs) … were promoted as replacements for CFCs and HCFCs." ​​​​​​​​​​​​​​​​​​​​​​​​​
HFCs are not ozone-depleting, but do "have global warming potentials ... ​ thousands
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of times greater than CO2 with atmospheric lifetimes" of "a decade or two".
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“Hydrofluorocarbons (HFCs) … are deemed ‘super-greenhouse effect’ gases.”
By US Govt - NOAA's Annual Greenhouse Gas Index (aggi), figure 2, Public Domain, https://commons.wikimedia.org/w/index.php?curid=123611
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Nitrous Oxide - N2O
"Other greenhouse gases, ... besides CO2 and methane, [are] nitrous ​ oxides,
... and ... chemicals used for refrigerants, hydrofluorocarbons [HFCs]." ​
Like the CFCs, N2O (nitrous oxide) acts as a greenhouse gas that also messes up the ozone (O3) layer.
Without an ozone layer in the stratosphere, "absorbing ... UV radiation from the sun", there’d be more:
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“skin cancer and cataracts in humans, harm to plants ... crops and animals [such as] fish, crabs & frogs."
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Unlike CFC refrigerants, N2O has yet to be banned.
Nitrous oxide emissions are growing and are "outpacing expectations.”​
How does N2O get into our air?
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- synthetic nitrogen fertilizers &
"livestock manure (42%),
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- runoff ... of fertilisers (25%),
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- biomass burning (10%),
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- fossil fuel combustion and
industrial processes (10%) ...
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- human sewage (5%)" and
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- "as an anesthetic [laughing gas] ...
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- in food aerosols [whippets] ...
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- in automobile racing"
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​ Regarding industrial sources of N2O:
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“‘What is needed … [are] … strong regulations and enforcement’.”
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"The US and China account for nearly 80% of industrial N2O emissions." ​​
Other N2O sources are "fossil-fuel combustion in vehicles, ... forest fires, ... and residential wood burning." ​
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For more on how to boycott N2O pollution, visit these pages: Automobiles, Smoke, and Agribusiness. ​​​​​
Fertilizers are the biggest source of N2O.
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Farmland application of "excess nitrogen [fertilizer] contributes to soil, water, and air pollution." ​
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In 2020, 100 million tons of such fertilizers were used worldwide, as well as 100 million tons of manure.
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On a positive note, limiting "nitrogen fertilizers and animal waste can ... reduce [ghg & water] pollution." ​
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"The previous top emitter, Europe, ... reduced its emissions [of agricultural N2O] by roughly 30%."
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Nitrogen Oxides - NO, NO2
"NOx does not include nitrous oxide (N2O)."
Nitrogen oxides (NOx) are pollutants distinct from nitrous oxide (N2O)!
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To spell it out:
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N2O depletes ozone (O3) in the upper atmosphere (not good!).
NO2 helps create O3 in the lower atmosphere (also not good!).
Ground-level Ozone
NOx is "nitric oxide (NO) [and/or] nitrogen dioxide (NO2) ... nitrogen oxides that [cause] air pollution.
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These gases contribute to ... smog and acid rain, as well as" adding ground-level ozone (O3).
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“NOx gases are usually produced … during combustion of fuels … at high temperatures ... in car engines.”
"When NOx and volatile organic compounds (VOCs) react [with] sunlight, they form photochemical smog."
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"Children, people with ... asthma, and people who work ... outside are ... susceptible to ... effects of smog."
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Volatile Organic Compounds - VOCs
VOCs are "indoor air pollutants ... outdoor air pollutants" and ground-water contaminants.
​​ VOCs include a
- butane
- acetone
- propane
- benzene
- isopropyl alcohol
- formaldehyde
- PVC ​​​​​​​​
They are used
in many items:
- "paints ...
- paint strippers ...
- pesticides
- building materials ...
- glues
- adhesives
- permanent markers
- photographic solutions."
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- "petroleum fuels
- hydraulic fluids ...
- dry cleaning agents"
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VOCs are used for:
- cleaning
- disinfection,
- and hygiene
​ "Health effects include:
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- eye,
- nose, and
- throat irritation
- headaches
- loss of coordination
- nausea
- kidney, and
- central nervous system." ​​
Outdoor "ground-level ozone ... triggers a variety of health problems"
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- asthma - cancer - nervous system disorders - birth defects -
Outdoors, VOCs generate unhealthy smog (see diagram).
“The pollutant gases made by car engines include ...
carbon monoxide, as well as VOCs ... and nitrogen oxides that cause smog.” ​​
​​ Catalytic converters have been helpful with the smog part of this problem:
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"A catalytic converter converts carbon monoxide [CO] into carbon dioxide [CO2],
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hydrocarbons [derived from fossil fuels] into carbon dioxide,
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and water and nitrogen oxides [NOx] into nitrogen and oxygen."
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But, as you may recall, while CO is bad, CO2 is the biggest of the greenhouse gases.
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Carbon Monoxide - CO
Two chemicals have decreased in our atmosphere since 2008, Carbon Monoxide (CO)
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and Sulfur Dioxide (SO2). ​ That's good, but not quite as good as it might appear.
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Re CO: "The burning of ... coal, gasoline, oil, natural gas, and wood can emit CO."
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“Combustion engines, blast furnaces, and fireplaces ...
wildfires & agricultural fires are ... major sources of the pollutant."
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Less CO is welcome: It "reacts in the atmosphere to produce methane and ozone.”
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But some of the reduction is “‘due to a shift from people burning coal in their homes to
using ​ ["natural"] gas or electricity coming from power plants that produce other pollutants’.”
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Sulfur Dioxide - SO2
“Acid rain stripped forests bare [and] wiped lakes clear of life.”
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“The cause was ... [SO2 and NOx] emitted by … cars, … smelters, and coal-burning utilities.”
"SO2 and NO2 … particles can enter the lungs and cause lung disease, heart attacks, and ... asthma."
The reduction of acid rain in America and Europe was a environmental success story.
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What happened?
Hard-won “international agreements, ... emissions limits on power plants, and ... reduced coal burning.”
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Emission limits were accomplished by using SMOKESTACK “scrubbers”. ​
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“In a ‘wet scrubber,’ the untreated exhaust is sent through a spray chamber
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where fine water droplets knock down the harmful [SO2] particulates.”
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Scrubbers are "expensive … it could cost more than ... $165 million to retrofit an existing facility.”
“While the major problem of sulfur dioxide was addressed [in Europe & America], other threats remain.
‘NOx in the air -- [from] car and truck exhaust -- also ... impact ... ecosystems and watersheds’.”
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"’We still have more acidity in rain than we should have'."
Another problem with sulfur dioxide is global cooling. Nope, not a joke. :-{
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Airborne SO2 prevents some sunlight from reaching the earth - resulting in somewhat cooler temperatures!
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A 1974 “study warned that the greenhouse effect could become a major problem if improved
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pollution-control measures reduced the countervailing cooling effect of small particles in the atmosphere.”
That’s right, with LESS sulphur dioxide, there’s MORE global warming!
SO2 has kept us a bit cooler, but it's no good: “Sulfur dioxide causes ... harmful effects in the lungs.”
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We're "reaping the results of … our ‘Faustian bargain’ with [local] air pollution.
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For decades, [localized] air pollution from [SO2] and ... other hazardous substances in fossil fuels
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has had a strong temporary cooling effect on our climate.”
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Sulfate aerosols created by "burning fossil fuels, reflect sunlight away ... and help cool the planet slightly.”
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Since we began "to clean up the air, the [global] cooling effect ... has fallen by around 30 percent.”
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The upshot is: we're going to have to double down on our global-warming-pollution prevention efforts!
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Other Pollutants
Visit the House page for information about home air and water filters.