Questão | Responda |
minerals | naturally occurring elements and compounds |
rocks | mixtures of minerals |
Ores | rocks that contain a large enough concentration of a particular to profitably mine and extract it |
Clean air is 78% | Nitrogen (nearly inert) |
Clean are is 21% | oxygen (highly reactive) |
Clean air is 0.93% | Argon (inert) |
Clean air is 0.03 to 0.04% | Carbon Dioxide (puts out fire but acidifies H2O) |
Two sources of pollutants | People and Natural (trees and volcanos) |
Major classes of pollutants | Particulates, nitrogen oxides, sulfur oxides, carbon oxides, hydrocarbons, ozone, misc air toxics |
Primary category of atmospheric transformation | straight from tail pipe, exhaust stack, fume hood vent (like SO2, CO2, NO, many HCs) |
Secondary category of atmospheric transformation | produced in atmosphere by chemical reactions often requiring UV |
Examples of Second category of atmospheric transformations | simple dissolutions in water, UV power splitting, oxidations, exotic combinations |
examples of simple dissolutions in water | CO2 + H2O --> H2CO3 (carbonic acid) SO3 + H2O --> H2SO4 (sulfuric acid) |
example of UV power splitting | NO2 --> NO + O (atomic oxygen, reactive) |
examples of oxidations | 2SO2 + O2 --> 2SO3 2NO + O2 --> 2NO2 HCs + O (atomic) --> aldehydes |
examples of exotic combinations | NO2 + O + HC --> PANs O2 + O --> O3 (ozone) |
PANs | Peroxyacyl nitrates, principal ingredient in photochemical smog |
Types of Smog | Industrial Smog and Photochemical Smog |
Industrial Smog | appears early in demographic transition (exclusively almost in developing countries), contains mostly primary air pollutants: particulates and sulfur oxides (often contains lead) |
Photochemical Smog (photo means it needs UV to create it) | typical of car rich societies late in demographic transition, contains lots of secondary pollutants (ozone, PANs), low particulate levels let in the UV better |
Effects of topography and cities | Temperature (or thermal) inversions, urban heat islands, dust domes |
Temperature (thermal) inversions | layer of warmer air above a volume of cooler air prevents mixing (ex: smoke rising upwards) (abnormal: usually temperature falls as you go higher) |
Urban Heat Islands | cities usually a few degrees warmer than the surrounding suburbs or country side |
Dust Domes | rising air above a city raises a tower or dome of particulates and particle-absorbed pollutants. When the wind picks up, this dome is smeared across the down wind landscape to produce dust plume |
Pollution effect on humans | mostly respiratory, decreasing lung function, emphysema, chronic bronchitis, asthma |
Effect of clean air act (since 1970) | big reduction in particulates (industrial smog ingredient), modest improvements in other classes except nitrogen oxides (got worse) |
Dirtiest US cities | Los Angeles (33 days above quality standards limits), Houston (44 days) |
Cost to clean up particulates | easiest to clean up (w/ bag house, scrubbers, electrostatic precipitators (most improvement) |
Cost to clean up sulfur oxides | should be easy to fic (got technology to do so) but we havent cut the levels in half in 1970) |
Cost to clean up NOx | toughest to reduce of the major classes (since cars make them), car has past hard emission tests to stay on road in MA) |
Cost to clean up CO2 | cannot clean up w/out putting more CO2 in the air than you removed. Requires a move to renewable plus H2 powered vehicles to reduce emissions |
Forests replanted for commercial harvest have | little species diversity |
Monocultures | Tree plantations have become essentially this |
Ecologically sustainable forest management | nontraditional method of forest management that seeks not only conserve forests for timber harvest but also to sustain biological diversity, prevent soil erosion, and preserve watersheds |
When logging occurs | unlogged areas are set aside as sanctuaries for organisms |
Wildlife corridors | protected zones that connect isolated unlogged areas |
Green wood | certified by Forest Stewardship Council based in Mexico to have been produced through environmentally sound and socially responsible management practices (can be bought) |
Selective Cutting | mature trees are cut individually or in small clusters, while the rest of the forest remains intact (example of uneven aged management) |
Uneven-aged management | in general results in better retention of biodiversity resulting from the forest's ability to reseed itself |
Selective cutting has been argued to | not be profitable because it requires more planning and skill (private foresters have been able to make profit off it) |
Shelterwood cutting | mature trees are removed from a forest in several harvests (usually three) over a period of time |
Harvests of shelterwood cutting | first harvest pulls out dead wood, unwanted tree species and some mature canopy trees, while leaving others to seed the opens left by the first cut. More canopy trees are removed in the second cutting, but a few are left to shelter the seedlings. Finally, the remaining canopy trees are cut, leaving a fairly even aged stand of saplings |
Seed tree cutting | almost all trees are harvested from an area, the few remaining trees provide seeds for the regeneration of the forest |
Clearcutting | all trees are removed from an area. Clear cut areas require reseeding by humans |
Which type of cutting has less negative impact on forests (like soil erosion and reduced leaching losses of nutrients), but not as economically profitable in short term | Selective cutting and shelterwood cutting |
Strip cutting | clearcuts are made of strips of forest narrow enough to allow effective reseeding by trees adjacent to the strip. Years later, the neighboring strip is cut so the forest is fully cut but not at the same time (this method greatly reduces soil erosion) |
Deforestation | temporary or permanent removal of forests for agriculture of other uses |
Deforestation causes | decreased soil fertility and increased soil erosion, impairs watershed functioning, contributes to the extinction of species, may induce regional and global climate changes |
Tropical Forests | destroyed to provide colonizers with temporary agricultural land, obtain timber (for HDCs), provide open rangeland for cattle, supply firewood and charcoal for fuel |
Boreal forests | currently world's primary source of industrial wood and wood fiber (extensive deforestation begain in late 1980s and early 1990s |
Reasons to preserve biodiversity | future drugs, future crops (new crop series, new genes), aesthetics/tourism |
Main reasons for species endangerment | habitat loss, exotic invaders, pollution, overexploitation |
Habitat loss | degradation and fragmentation, biggest factor for most species |
Exotic Invaders | brown tree snake on Guam, mongoose in Hawaii |
Pollution examples (SE) | lead shot versus condors, UV versus amphibian eggs (big problem for fish) |
Bellweather or sentinel species | pollution species organisms (like amphibians or canaries in a coal mine) |
Overexploitation (SE) | major factor for reptiles, hunt/poached for food (passenger pigeons), poaches for non food products (furs, traditional medicine, rhino horns, pet/zoo trade |
How to help biodiversity | habitat preserves, zoos/botanical gardens, DNA in liquid N2 |
Problems with reintroductions and recovery of small populations (Allee effects) | widely scattered individuals cannot find mates (blue whales), lek breeding males fail to achieve critical mass to attract females (Kakapo), colony breeders may need behavorial cues from neighboring breeders to be fertile, highly social pack species may fail to achieve min viable pack size for hunting |
High grade ores | contain relatively large amounts of particular minerals |
Low grade ores | contain lesser amounts of particular minerals |
Metallic minerals | iron, aluminum, and copper |
Nonmetallic minerals | phosphates, salt and sand |
Mineral reserves | deposits that have been identified and are profitable to extract |
Mineral resources | deposits of low grade ores that may or may not have been prfitable ti extract in the future but are not presently profitable or possible to extract |
Total resources or world reserve base | combination of a minerals reserves and resources |
Steps to convert mineral deposit into a usable product | locating deposit, mining and processing/refining |
If deposit is near the surface, it is extracted | by open pit surface mining or strip mining (just like for coal) |
Subsurface mines (shaft mines or slope mines) | side of mountains, are used to obtain minerals located deep in earth's crust |
Smelting | needed for processing minerals, it is melting the ore at high temperatures to help separate impurities from molten metal, commonly used to convert metal from an oxide |
Idea behind smelting | carbon (from coal processed into coke) wants to be oxidized more desperately than metal does (at high temp). Mixture of coke and metal oxide ore is heated up so that O2 will be low |
Any form of mineral extraction and processing has | negative effects on the environment |
Acid mine drainage | acid and other toxic compounds in the spoil banks of mines cause this, and it harms surface water, soil and groundwater |
Mineral processing can cause | air, soil and water pollution |
Tailings | the impurities that make up 80% of mine ore (often left in giant piles near processing plants) |
Toxic materials that leach into the environment from tailings | mercury, cyanide, and sulfuric acid |
Dead Zone | vegetation is killed in the area from smelting plants (Ducktown TN, Copper Basin, Sudbury Ontario, Severonikel nickel smelter in Russia) |
Derelict Lands | are extensively damaged due to mining but can be restored to prevent further degradation and to make the land productive for other purposes |
Land reclamation | extremely expensive |
Phytromediation | the use of plants to remove contaminants |
Hyperaccumulators | plants that are used for remediation of metals must be unusually resistant to the toxicity of the metals should be these and HAs extract large quantities of the metals from the soil and storing all that they extract in their own tissues |
HDCs consume | too much of the world's minerals |
HDC's rely on | Developing nations for their minerals |
Life Indices | the length the reserve of certain minerals will last |
Biomining Techniques | use microbes profitably to extract copper or gold from ores that could not be mined by conventional means. Causes far less environmental disruption than strip mining. Wells are needed and ore deposits need to be fractured |
Substitution and conservation | extend mineral supplies |
Manufacturing industries | continually try to substitute more common, less expensive minerals for those that are scarce and expensive |
Reuse | product is collected and used over again |
Recycling | discarded products are collected and reprocessed into new products |
Reuse and recycling cause | less pollution and save energy compared to the extraction and processing of virgin ores |
Danes law | banning non reusable containers |
Eleven US states | have deposit laws |
Sustainable manufacturing | minimization of waste during industrial processes, including reuse and recycling either intentionally or in cooperation with other industries |
Dematerialization | decrease in size and weight of a product as a result of technological improvements over time, only reduces consumption if products are durable and easily and inexpensively repaired |
Industrial Ecology | extension of the concept of sustainable manufacturing in which resources are used efficiently and wastes are regarded as potential products |
CO2 concentrations have been | increasing since the industrial revolution |
Average global temperature has | increased since the industrial revolution |
For earth's temperature to equilibrate | rate of heat addition (from sun) = rate of heat loss (via IR) |
CO2 intercepts | IR radiated from earth before it can reach space |
CO2 has changed from 288 ppm to | 371 ppm since IndRev |
Methane has changed from 848 ppb | to 1783 ppb since IndRev |
Nitrous oxide has changed from 285 ppb to | 315 ppb since IndRev |
CFCs have changed from 0 to | a very potent ppt since IndRev |
Global warming model predictions | cooling of stratosphere, average temp increasing near poles more than equator, rise in sea levels (due to expansion of water - not from melting ice) and retreat of glaciers at both high latitude and high altitude |
Global Dimming | overall reduction in the amount of sunlight that reaches the earth over the last 30 years |
Extend of global dimming | antartica --> USA --> UK --> Israel --> Russia |
Two causes for global dimming | particles and aerosols in air pollution directly reflecting or blocking sunlight, pollution particles serving as unnaturally abundant condensation nuclei |
Role of particles and clouds documented by a $25 million study in | the Maldives |
Role of pollution particles as condensation nuclei documented after 9/11 when all aircraft were grounded | the temperature range from high and low temps, was 1 degree wider than usual, reflecting the unusually low amount of clouds and vapor trails |
Problems with global dimming | changes in rainfall patterns and masks global warming |
Changes in rainfall patterns from global dimming | failure of monsoons to shift to prevent droughts |
Masking global warming during global dimming | GW has added 2.6 extra watts of energy per square meter of Earth's surface (GD has subtracted 1.5 watts) |
The project doubling of atmospheric CO2 concentrations will occur in | 2050 |
As CO2 concentrations increase, photosynthesis rates will | increase |
cellulose and lignine are more difficult to | digest for organisms |
High CO2 grown plant tissues are generally | less nutritious for the organisms that eat them |
Sap sucking aphids reproduced 10% to 15% | more rapidly under elevated CO2 |
Ruminant animals (sheep and cows) rely on | microbial symbionts to digest plant material for them |
Microbial fermentation of plant tissue is | slower for plants with high C:N ratios |
An increase in CO2 forces ruminants to | slow down the rate at which they are eating tissue of decreased nutritional value - animal growth rates slow |
Plants with nitrogen fixing symbionts (legumes) may | thrive under conditions of elevated CO2, which decrease the cost of photosynthate they pass to the bacteria in exchange for nitrogen |
The ozone layer in the stratospere helps to | shield the Earth from about 99% of harmful UV radiation |
Tropospheric ozone does | not help to block enough UV |
Ozone (O3) | absorbs essentially all of the most injurious band of ultraviolet light from the sun, UV-C, UV-B, UV-A |
The energy carried by a photon is inversely related to | its wavelength |
UV-B photons are more energetic and destructive than | a UV-A photon |
UV-B photons can cause | mutations that can result in cancer |
UV-A photons cannot | induce cancer |
The total amount of ozone in the stratosphere is | slowly declining globally |
Large ozone holds develop over | Antarctica and the Arctic each year |
CFCs are responsible for | attacking the ozone layer |
key molecular features that allow CFCs to be ozone destroyers | small enough to be highly volatile, almost inert in the trophosphere, carry chlorine up to the ozone layer, chlorine atoms can be released from CFCs by UV |
Each atom of Cl in the stratosphere can help the | destruction of up to 100,000 O3 molecules |
Additional compounds that also attack ozone include | halons, methyl bromide, methyl chloroform, carbon tetrachloride, and maybe nitrous oxide |
One bromine atom destroys more Os than | one chlorine atom |
Circumpolar vortex | mass of cold air that circulates around the southern polar region, that isolates the cold air from the rest of the planet's warmer air |
In humans, excessive exposure to UV radiation causes | cataracts, weakened immunity, and skin cancer |
increased levels of UV radiation may disrupt | ecosystems because the negative effect of one species has ramifications throughout the ecosystem |
Plants who suffer about 1% decline in productivity | from a 3% drop in stratospheric zone |
Montreal Protocol | agreement to plase out CFC production, aimed for 50% reduced production of CFCs by 1998 |
From the Montreal Protocol, countries stop producing dangerous gases besides two | CFC-12 and Halon-1211 |
Elimination of CFCs was largely achieved through substiturion with other compounds such as | HFCs, HCFCs, and Terpenes |
HFCs | refrigerants that contain no chlorine or bromine, do not damage ozone layer, but they persist in atmosphere longer |
HCFCs | pose 90% less danger to ozone layer that CFCs but they may lower energy efficiency of appliances |
Terpenes | from citrus rinds, make good substitutes for cleaning silicon chips and electronic parts |
Human's balanced diet | includes carbohydrates, proteins, lipids, vitamins, minerals, and water |
Undernourished | consume fewer calories than they need |
malnourished | consume enough calories but diet lacks some specific nutrients |
Marasmus | resulting from caloric and protein insufficiency |
Kwashiorkor | protein insufficiency even if caloric intake is adequate |
overnourished | consume food in excess |
two regions of the world with greatest food insecurity | South Asia and sub-Saharan Africa |
Famines | severe food shortages |
World grain carryover stocks | amounts of rice, corn, wheat, and other grains remaining from previous harvests, as estimates at the start of new harvest |
Food security | goal in which all people have access at all times to adequate amounts and kinds of food needed to lead healthy, active lives |
minimum days needed for carryover stocks to last | 70 days |
Cold blooded animals need | least (example: farmed fish need 1.5 lb of feed per lb of meat produced |
Mammals need | 6 and 7 lbs of grain per lb of pork and beef |
Chickens only need | 2.7 lb of grain per lb of meat |
Farmer methods to achieve higher rates of production | have been non-sustainable (irrigation supported by aquifer depletion or nitrogen fertilizers manufactured with fossil fuels |
100 plants provide | 90% of the food humans consume |
top 5 plants for human consumption | sugar cane, corn, rice, wheat, white potato |
Rice, wheat, and corn provide | half the calories people consume |
high input agriculture | produces high yields (amounts of food produced per unit of land), requires a lot of energy |
Subsistence agriculture | production of enough food to feed oneself and one's family (with little left over to sell or reserve) |
Shifting agriculture and nomadic herding are | examples are subsistence agriculture that are very land intensive |
Polyculture | type of substinence agriculture in which several crops are grown together at the same time |
When plants and animals are domesticated | much of the genetic diversity found in wild populations is lost |
Agriculture protects | domesticated plants and animals as much as possible from pests and diseases |
Green revolution | new high yielding varieties are intensively cultivated with mechanized machinery, commerical inorganic fertilizers, and pesticides (begain in 1960s) |
Change in farming practices involve three steps | developing and planting selectively bred, high yield varieties of a small number of crop species, increasing inputs of agrochemicals to maximize their yield, often increasing frequency of cropping |
The green revolution gave Latin America and Asian countries | the chance to produce adequate supplies of food |
America doubled its agricultural output | since 1940 without an increase in cultivated acreage |
India doubled total food production between | 1970 and 1992 |
The green revolution has not benefited | Africa because their common crops have not been greatly improved by green revolution technology |
The use of hormones and antibiotics has | increased animal production |
Antibiotics prevent | disease spreading between large tightly packed animals |
The European Unions bans imports of hormone fed beef because | of health concerns (even tough hormone fed livestock do not pose health concerns) |
Maintaining a permanent layer of mulch on soils in areas of high rainfall or steep slopes | method to make subsistence agriculture sustainable and more productive |
Alley Cropping | growing of crops between rows of woody deep rooted pruning tolerant species |
Deep roots of alley cropping | keep system tight towards leaching losses of nutrients |
Heavy pruning needed to reduce the canopy during seedling establishment | provides trimmings to use as mulch and a slow release source of nutrients, particularly if the woody species is a legume |
Alley cropping works best at | very low altitudes with woody species being planted in rows running east to west to minimize shading of the crops |
Genetic engineering | transfer of specific genes from one species to another (high tech answer to some agriculture's challenges) |
Genetic engineering produces food plants that are | more nutritious, resistant to insect pests and viral diseases, more tolerant of drought, heat, cold, herbicides, or salty soil, and resistant to herbicides (Monsanto) |
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