envrionmental science exam 3 Flashcards
food security
Guarantee of adequate, safe, nutritious, and reliable food supply available to all peoples
In general, food production has kept pace, or even exceeded, population growth.
However, many of the world’s soils are in decline and most arable lands are already utilized
undernutrition
Receiving fewer calories than dietary requirements
Globally, undernutrition is falling. Less, people going hungry
over nuturition
Consumption of excess calories
In U.S. more than 1/3rd of population is obese
Non-communicable diseases are at their highest rates: cardiovascular disease, diabetes, cancers, etc
malnutrition
Failure to obtain adequate vitamins, minerals, proteins, fats, etc from foods
Example: Protein deficient diets can lead to children developing kwashiorkor, this combined with inadequate calories can lead to marasmus
traditional agriculture
Began about 10,000 years ago
polycultures
mixture of different plants grown together
machinery
allowed for faster cultivating ,harvesting and transporting and processing of crops
monocultures
vast areas of single crops not mixed ,reduces biodiversity also more susceptible to pests and disease
traditional farming - slash and burn
cut down and burn forests to clear land for monocultures or animals
Destroys habitats and releases GHGs
Input of fertilizers and use of pesticides interrupt natural cycles and pollute water and soil
Inefficient use of water through wasteful irrigation
Lack of crop rotations and overgrazing depletes soils and can lead to desertification
tilling
Leaves soils exposed to wind and water. Erodes over time
sustainable farming
intercropping -Plant mixed varieties, better mimicking natural ecosystem, less cutting of trees
Plants used that mutually benefit, also adds to surrounding ecosystem
Use of compost and natural fertilizers. Organic
Slower release of nutrients, less likely to negatively impact natural cycles, reduces environmental loads
Targeted application of water and fertilizers
Crop rotation: Alternate crops grown each year/season
No Tilling: Crop residues and plant material are left. Creates barrier that protects soils from erosion and degradation
pests
Can damage crops, especially monocultures because they easily move from plant to plant
weed
Any plant that competes with crops
pesticides
Poisons applied to kill pests and weeds because monocultures lack natural protections
Typically decline in effectiveness over time as pests and weeds gain resistance
Some pests survive > pass on resistant genes > pesticides become less effective > more toxic pesticides used > cycle repeats
biological control
Use of organisms that compete or consume pests/weeds
integrated pest management
Use of organisms that compete or consume pests/weeds
pollination
Male sex cells of plant (pollen) fertilize female sex cells
mutualistic interaction
Pollinators get nectar, plant gets fertilized
pollinators
are declining due to impacts from industrial agriculture
Insecticides, loss of habitats, invasive parasites and pathogens, human exploitation
colony collapse disorder
majority of worker bees disappear, colony dies
1/3rd of U.S. colonies collapse each year
animal agriculture
Since 1950: Global meat production increased 5x
Some animals convert crops or grass more efficiently
Feedlots (factory farms): Huge warehouses that raise animals for food in high densities
Positives: More efficient. Less land used. Cheaper and higher production
Negatives: Large consumption of grains. Raises prices of otherwise cheap crops. Waste pollutes nearby soils and waterways. Heavy use of antibiotics creates resistant strains of diseases
Major contributor to GHG emissions: Methane and nitrous oxide much stronger GHGs than CO2
overharvest
is collapsing wild sea life populations
aquaculture
Cultivation of aquatic organisms for food in controlled environments
postive
Reduces pressure on wild populations. Consumes fewer fossil fuels. Safer working environment. Can be quite energy efficient
negatives
Large amounts of waste. Fed grains which can raise prices. Some fed fishmeal from wild caught, adding to pressure. Fish can escape and spread disease or outcompete natives (if invasive)
Genetically Modified Organisms (GMOs)
Genetically engineered using recombinant DNA, patching DNA together from multiple organisms
Goal is desirable traits: faster growth, disease resistance, higher nutrition, etc
Difference from artificial selection:
Mixes DNA of different organisms/species
Genetic material mixed in labs, not existing in nature
Creates novel combinations directly
pros and cons for genetically modified organisms
cons - adverse effects of GM foods on health are the transfer of antibiotic resistance, toxicity and allergenicity.
pros -More nutritious food.
Tastier food.
Disease- and drought-resistant plants that require fewer environmental resources (such as water and fertilizer)
Less use of pesticides.
Increased supply of food with reduced cost and longer shelf life.
Faster growing plants and animals.
biodiversity benefits
food security- Biodiversity reduces crop failures and helps prevent rapid spread of diseases between animals
medicine -Made from plants and animals for centuries. About half of modern pharmaceuticals derived from wild plants.
Many species not discovered yet, many more medicines to find
ecosystem services
Provides goods and services like food, fuel, plant pollination, pest and disease control, aesthetic benefits, etc
17 ecosystem services estimated to be worth $148 trillion per year
functional ecosystems
Increases resilience of ecological systems. Keeps them stable, balanced, and healthy
economic
: Tourism and recreation
biophilia
People see inherently value life and its diversity
biodiversity loss
Human disturbance tends to make ecosystems more similar
Creates “winner” and “loser” species. Generalists typically winners while specialists losers
population shrinking creates two main issues
Loss of genetic diversity
Reduced geographic range
extirpation
Disappearance of a species from an area, not globally
6th mass extinction
Global extinction rate is 100-1000x higher than background rate
About 20% of (known) species are threatened
archeological evidence
Supports that human arrival to islands and continents typically followed by extinctions
habitat loss
Greatest threat. Either destroyed, fragmented, or degraded
habitat fragmentation
Breaking up of continuous habitat into separated pieces through farming, logging, roads, development, etc
wetlands
More than half in U.S. and Canada drained for agriculture
great plains
Less than 1% untouched. Grassland bird species 82-99% loss
pollution
Harm organisms and ecosystems in various ways:
Noise and light pollution interfere with animal behaviors and patterns
Agricultural runoffs, oil spills, plastics, heavy metals and endocrine disruptors
overharvesting
Hunting or harvesting unsustainably
Poaching: Unlawful killing of species for meat or body parts, mainly large animals like elephants, rhinos, sharks, whales, etc
invasive species
Can outcompete, prey upon, or displace natives
Pet trade escapes, transported through human movement, escape of captive animals (aquaculture), transfer of diseases (bacteria and viruses)
some intentional
moving plants or animals into areas for human benefit. Typically beneficial to humans but detrimental to local ecosystems
climate change
climate patterns and weather changes. Difficult for most species to adapt to such significant, quick changes
Loss of ice in artic affecting species like the polar bear
conservation biology
Scientific study and pursuit to understand the processes that influence the loss, protection, and restoration of biodiversity
endangered species act
Enacted in 1973. Offers protection to species that are endangered or threatened.
endangered
Danger of going extinct
threatened
Vulnerable to becoming endangered
Forbids government and citizens from harming individuals or their habitats and forbids trade in products made from species
captive breeding
Individuals bred and raised in controlled conditions with intent of reintroducing to wild
species successes
bald eagle, peregrine falcon, brown pelican
biodiversity hotspot
Region that supports a great number of endemic species
Very valuable pockets of high biodiversity, hence protection
parks and protected areas
Setting aside of undeveloped lands
Nearly 15% of world’s land
Pressures from outside reserves can still negatively impact populations within
community based conservation
Conservation biologists working cooperatively with local communities to protect ecosystems and wildlife
25% of world’s protected areas
fossil fuels
Highly combustible substances formed underground over millions of years from buried remains of dead organisms
Coal (solid), Oil (liquid), and Natural gas (gas)
Replenish very slowly: Would take millions of years to replenish what we’ve used
net energy
Energy returned – Energy invested
EROI
Energy returned on investment
higher EROI
more energy gained per unit invested
Lower EROI
less energy gained per unit invested
fossil fuel formation and extraction
Formed when organic material (dead and decaying organisms) are broken down over millions of years in anaerobic environment (oxygen depleted) and heat and pressure are applied over time.
coal
Most abundant fossil fuel. Mostly formed from woody plants
strip mining
extraction near surface
subsurface mining
extraction of deep underground deposits
oil and natural gas
Mostly formed from dead plankton. Oil is high concentration of hydrocarbons while natural gas is methane
reserves to production ratio
The remaining reserves of a fossil fuel divided by production (extraction)
Oil R/P ratio
50 years
Natural Gas R/P ratio:
50 years
coal R/P ratio
150 years
Once “Peak Oil” occurs
we may face economic and societal collapse and/or it could push developments to conserve or exploit new energy sources
clean coal technologies
techniques and equipment that remove chemical contaminants like sulfur, mercury, and arsenic during generation of electricity from coal
scrubbers
devices that chemically convert or physically remove pollutants
carbon capture
Capturing CO2 emissions, converting from gas to liquid, then storing underground or under ocean
energy efficiency
Same energy output with less input
energy conservation
Practice of reducing wasteful or unnecessary energy use
energy itensity
Energy use per dollar of Gross Domestic Product (GDP)
U.S. energy intensity has lowered to less than half of what it was about 70 years ago
cogeneration
Excess heat from producing energy is utilized to heat homes, workplaces, or produce other kinds of power
Energy Efficiency and Conservation Cont
Ways to save energy: Smart building design to reduce heating and cooling costs, energy efficient lightbulbs and appliances, etc
fuel efficiency
hybrid, electric, and hydrogen cell vehicles can reduce carbon emissions and improve air quality
Government has ramped up required fuel efficiencies for vehicles over time:
rebound effect
Increases in efficiencies may lead to increased consumption of energy and/or fuel
nuclear energy
Energy that holds together protons and neutrons in nucleus
nuclear fission
Nuclei of large, heavy atoms like uranium or plutonium are bombarded with neutrons and split
chain reaction
Nucleus split leads to release of further neutrons, which then impact other nuclei, releasing more energy and neutrons
nuclear
is cleaner than fossil fuels, but can lead to major accidents (Chernobyl, Three Mile island, Fukushima, etc)
nuclear wastes
Difficult to dispose of because they will continue to emit large amounts of radiation.
Due to fears of accidents and issues with waste disposal, nuclear power’s growth has slowed
renewable benefits
Inexhaustible, long-term security
Energy diversification, reduces price volatilities and reliance on imported fuels/energy
Help those in remote areas or developing countries produce their own energy
Reduce air pollution
Slow climate change
policy
can help promote renewables through green subsidies, tax credits/rebates, etc
critics
Believe such funneling of taxpayer money towards renewables is inefficient and potentially skews the market. Not a “level playing field
supporters
Point out that governments have long subsidized fossil fuel industries and still do, so never was nor is a “level playing field”
In the U.S
Oil and gas have received 75x more subsidies than renewable energy
per year basis
13x more than renewable energy
For every $1 in taxpayer money towards renewables, $4 towards fossil fuels
photovoltaic cells
Convert sunlight to electrical energy through electrons movement through silicon plates
net metering
Energy that the homeowner provides (like through solar power) is subtracted from the homeowner’s utility bill
benefits
Inexhaustible, enough to power all human civilization (just need to harness it)
No fuel required or emissions
No moving parts and require little maintenance
drawbacks
Location: Not all regions receive equal amounts of sunlight
Timing: Daily or seasonal variations in sunshine will impact power production
Cost: Up-front costs of equipment, although prices are dropping over time
bioenergy
Energy acquired from the chemical energy stored in biomass (organic material)
Can be renewable, if not overharvested
Usages: Burn for heat, processing to create electricity, or transforming into liquid fuels
biopower
Biomass burned to generate electricity
Burn waste products like woody debris from logging, liquid waste from pulp mills, manure and wastes from feedlots or landfills, and residue from crops
biofuels
Liquid fuels, primarily used to power vehicles
Ethanol, biodiesel, fuels from algae, and cellulosic ethanol (made generally from plants rather than specific crops, like corn)
