Download Human Impacts on the Biosphere and more Exams Human Geography in PDF only on Docsity!
EEB 2100 UConn Exam 2024/
Main questions of course - ✔✔1. How do humans alter earth
- how do human alterations affect the biosphere
- What can be done to alleviate human alterations of the biosphere Greatest ecological impacts of humans(most to least) - ✔✔1. Nitrogen fixation
- Water use
- Land transformation
- CO2 concentration rise
- Ocean acidification
- Bird extinction
- Plant invasion Planetary Boundaries - ✔✔Limits between which global systems must operate to prevent abrupt and irreversible environmental change Planetary Boundaries that have been crossed - ✔✔1. Biogeochemical flows of Nitrogen and Phosphorous(Nitrogen fixation)
- Genetic diversity (biodiversity loss) Success story of planetary boundaries - ✔✔Restoration of the ozone layer Non-linear dynamics - ✔✔Outcome is not proportional to input
- to revert back to a stable state, it will take more effort than getting to where you are now(It takes much less equipment to pollute a pond than to clean it up after it has been polluted) Tipping Points - ✔✔a critical threshold when a small change can have potentially drastic effects. Mostly linked to climate change and pollution and the increase in the emmition of greenhouse gases Increased atmospheric CO2 - ✔✔Result of increased burning of fossil fuels and land use change(getting rid of plants by burning which uptake CO2)
- caused global warming of 0.8-1.2 degrees Celsius Oceanic CO2 - ✔✔-25% of carbon from CO2 gets taken up by oceans
- Caused the average ocean ph to drop by 0.1 units and because ph is a log scale resulted in 26% increased acidity causing major changes to ocean ecology nitrogen fixation - ✔✔process of converting nitrogen gas into nitrogen compounds that plants can absorb and use Nitrogen in Ecosystemsdont understand - ✔✔added to ecosystems through fixation by microorganisms and limits the growth of many ecosystems Large mammal biomass - ✔✔97% of large mammal biomass is human(30%) or domestic animals(67%)
periods: 50- 2 00 million years epoch: 5-30 million years Formal criteria for new geological time units - ✔✔1. Must be stratigraphic evidence(evidence in rock layers) for start date all over the world.
- Must persist for millions of years
- accompanied by a mass extinction "Golden Spike" - ✔✔(GSSP) Global Stratotype Section and point and refers to evidence in geological strata that signifies the start of a new geological stage of time. Example of golden spike and geological time shift - ✔✔Boundary between the cretaceous and paleogene periods that occured 66 million years ago with a meteor impact
- layer of iridium rock not common to earth found in strata all over the world
- global extinction of dinosaurs occurred How many mass extinctions have there been? - ✔✔five(not including the one currently going on) When should the Anthropocene begin?(Scientist arguements) - ✔✔1.mega faunal extinctions 50-10k years ago which was was defined by humans growing in numbers and over-hunting mega faunal animals
- Dawn of agriculture 11-8k years ago when hunting stopped and we stayed in one place to farm
- Globalization and columbian interchange(1492-1620)
- Industrial revolution(1760-1880)
- The great acceleration(1945-1965) {acceleration of population, factories and the rise of nuclear} Holocene - ✔✔Thought to be the current epoch extending back 10,000 years and characterized by earth stability Why mega faunal extinctions doesnt work as start of anthropocene - ✔✔Lack of synchrony of events globally. People didn't inhabit everywhere all at once and kill mega faunals right away. Dawn of agriculture Anthropocene arguments - ✔✔pros:
- Dramatically altered species composition cons:
- lack of synchrony all over the world
- secondary marks such as ceramics are not consistently associated with origin of agriculture Columbian exchange Anthropocene arguments - ✔✔pros:
- lots of exchange lead to pathways for disease and famine which lead to 90% reduction in human population(conflict also helped with this)
- reduction in people lead to rapid reforestation of the Americas(reduced atmospheric carbon by 7-10 ppm which is a potential marker or golden spike) Industrial revolution Anthropocene arguments - ✔✔pros:
much broader to include non-economic benefits such as art, psychology, etc...) acknowledges the fact that there are positive and negative aspects of this Example of natures contribution to people - ✔✔Natural capital- the global stock of natural resources which provide goods and services and sustain economies Global ecosystem organizations - ✔✔Millennium ecosystem assessment(2000-2005) which was the first global assessment of ecosystem threats IPBES- Intergovernmental science-policy platform on biodiversity and ecosystem services IPCC- intergovernmental panel on climate change for biodiversity and ecosystems IPCC - ✔✔Intergovernmental Panel on Climate Change who were the first to recognize climate change as a major threat to humans on earth Estimated value of nature - ✔✔$125 trillion per year with $4- 20 trillion being lost every year due to habitat loss Highest value items in nature - ✔✔Coral reefs- $198,000 per hectacre per year
costal systems- $26,000 per ha/y Wetlands- $17-12,000 per ha/y pollination services - ✔✔Used by 75% of crop species Pollination is done by wild bees and insects a majority of the time compared to the common European honey bee Coastal wetland importance - ✔✔Flood storage- naturally soaks up water and lets it slowly drain back out Storm surge buffer-wave energy is dampened by wetland vegetation and lots of water is absorbed erosion control- vegetation holds sand and soil in place during storms Water purification process - ✔✔Soil slows down the water and all the fine sediment drops down. Pollution is also dropped off and absorbed by plants. Micro-organisms also detoxify the polluted water as it travels through the ground. Company externalities - ✔✔Cost not placed on a company that is passed on to others. Carbon dioxide emissions are put on customers but private profits continue. Ecosystem Species Rivet analogy - ✔✔if the ecosystems species are rivets on an airplane you can remove some and still be fine,
Prosperity-better education and more opportunities and the realization that not many children were needed to continue a family into the future child survival- As more children survive, less have to be born Total Fertility Rate (TFR) - ✔✔The average number of children a woman will have throughout her childbearing years. It has gone from 5 to 2.5 in the past 50 years Population expansion in the world - ✔✔most expansive in the sub-Saharan Africa with negative growth of people in parts of Europe and japan Main driver of biodiversity loss - ✔✔All human driven: Habitat destruction(most cause) Over exploitation of species exotic species invasions disease climate change What defines human impact - ✔✔The total population, how much per capita consumption there is(affluence), technological increases that can mitigate effects. Expressed as the formula I=PAT I=PAT - ✔✔Impact = Population x Affluence x Technology Affluence - ✔✔how much consumption or use their is of something. for example, the US beef consumption has a larger
affluence than anywhere else in the world. Put in other words: many people in the population of the US enjoy beef Ehrlich vs Simon bet - ✔✔Ehrlich bet Simon(an economist) that the price of 5 metals would go up as they became more rare as the population and their use increased. Simon said they would go down because people would develop substitutes before the products got that scarce and that is exactly what happened, plastic became big and drove the prices down Technological innovation - ✔✔Will over-consumption and overuse overtake human ingenuity in finding more renewable and efficient ways to do things? Habitat - ✔✔Environment with conditions needed by an organism for its survival and reproduction Fitness - ✔✔an organism's ability to survive and reproduce in a particular environment. Habitat-loss - ✔✔complete conversion to non-habitat Habitat-degradation - ✔✔still a habitat but offers lower fitness to the organisms that are there Habitat matrix - ✔✔The uninhabitable environment that surrounds a habitat
Land Sharing - ✔✔Manage land for human uses and conservation simultaneously. ie; more fragmentation and making it multi-use Land Sparing - ✔✔Conservation is best achieved when we leave nature to its own devices. ie; larger reserves and less fragmentation SLOSS debate - ✔✔single large or several small reserves Single large reserve - ✔✔Jared diamond argued for a single large reserve stating that it protects more species because species diversity increases with area Several Small reserves - ✔✔Daniel Simberloff argued for several small reserves stating that it will protect more species because each patch has a different species(habitat variation) Single large reserve cons - ✔✔Lacks habitat variation that supports more than one species no redundancy if their is a catastrophe like a forest fire Difficult because people live everywhere Several small reserves cons - ✔✔Increased edge and more isolation because of smaller interior Several Small connected reserves??? - ✔✔Corridor project that connects small habitats by a corridor in a forest
allows for movement of organisms and increased diversity Half earth preservation - ✔✔Edward Wilson said to protect earth we have to protect half of the habitats; ambitious goal Green Striped earth - ✔✔Link habitats through extremely large corridors that work around urban areas to protect biodiversity Biggest risk to ecology - ✔✔Habitat loss and degradation How agriculture affects ecology - ✔✔PAT, what we eat the most of is produced the most Zero sum game - ✔✔Agriculture is a zero sum game; if people need more food, we must take away from wildlands to make space for agricultural fields slash and burn agriculture - ✔✔Prevalent in Brazil where forest is removed by first cutting down the vegetation and then burned away to make way for crop lands and give nutrients to the soil for growth. (soil only lasts 3-5 years) Agricultural fertilizers - ✔✔Nitrogen and phosphorous cycles have been hijacked by human needs and much less is left in a form usable to plants Eutrophication - ✔✔A process by which nutrients, particularly phosphorus and nitrogen, become highly concentrated in a body
Technological advances like fertilizers and pesticides allow us to increase our crop yields and keep up with growing demand, but this wont keep up forever A Hungry World - ✔✔most of the world is a little bit hungry with African and Middle Eastern countries being the worst. Climate change will make it harder to grow food in countries where it is already hard urban area definition - ✔✔greater than or equal to 4 people per hectare metropolitan area definition - ✔✔Group of cities or area where one city is greater than 50,000 people and total population is greater than 100, City - ✔✔greater than 50,000 people NE US - ✔✔The first megalopolis which contains 50 million people, 17% of the US population living on 2% of its land Worlds largest economic output based on size Ecological footprint - ✔✔a measure of a cities impact that includes the area around the city that is required to support it Urban area increase - ✔✔Very rapid growth, in 2007 the amount of people living in urban areas equaled the amount living in rural areas.
2/3rds of people expected to be in urban areas by 2050 Megacity - ✔✔Housing ten or more million inhabitants Heat Island effect - ✔✔Built features of cities raise temperatures relative to the surrounding area Urban area ecosystem - ✔✔Low native vegetation More pollution Fewer species but intense human interactions Biodiversity loss in cities - ✔✔Even with slight increases in urbanization, biodiversity decreases rapidly going from 1 to 10 households per hectare you lose half the species found in watersheds Habitats loose their specialists and gain generalists Urban ecology - ✔✔Study of relationships among species where humans are considered an important part of the ecosystem Environmental justice - ✔✔equal access to environmental services and protection from disservices in all places where people live, work, learn, and play Redlining - ✔✔Homeowners loan association created maps of neighborhoods in part based on race and class
Urban sprawl - ✔✔Low-density single family dwellings large dependence on automobiles and defined by outward growth from cities like Denver and Los Angeles What is acid rain? - ✔✔Sulfur dioxide and nitrogen oxides emitted from burning of fossil fuels which is deposited in the atmosphere which then dissolves into rainwater, sulfuric acid and nitric acid, to form acid rain PH scale - ✔✔Measure of the H+ ion concentration and is a log base 10 scale so a change by 1 ph indicates a 10x change in concentration Ph of natural rain - ✔✔5.1 to 5. Acid rain in NE - ✔✔Comes from coal emissions in the Midwest Cap and Trade program - ✔✔power plants are given a certain amount of emissions they could release and they could sell any allowances they didn't use to more dirty plants so they can make money for being cleaner than their competitors Acid Rain ecological impacts - ✔✔leaches calcium from soil which limits plant growth and damages trees creates a toxic form of aluminum that is spread between plants acidifies lakes which then start to loose sensitive species like trout
Clear air act - ✔✔Cost buisnesses $8 billion per year but benefitted the economy as a whole by $100 billion a year decreased coal plants (SO2) but not transportation (NOx) Sudbury copper/nickel smelter - ✔✔Produced more SO2 than all active volcanos at one point eventually found a way to mitigate pollution by capturing SO before it was released into the atmosphere and actually sold the product Acid rain today - ✔✔Still an issue but it has been reduced by 80% soil has been depleted of buffering so remaining acidity has a much bigger effect
