APES unit 9 (global change)

stratospheric ozone

ozone in the stratosphere absorbs UV-C and much of UV-B radiation

UV-B and UV-C

dangerous radiation for humans that can cause tissue damage and mutate DNA

how ozone absorbs UV-B and UV-C

UV-C breaks O2 into 2 free O atoms, which them bond with O2 to make O3, which then gets broken up, etc.

anthropogenic ozone depletion

CFCs are a primary anthropogenic cause of O3 breakdown

natural ozone depletion

antarctica spring melt forms polar stratospheric clouds (PSC)

polar stratospheric clouds (PSC)

clouds made of water and nitric acid, reacts with stuff to give off Cl2, which gets broken by the sun into 2Cl, then breaks down ozone

reducing ozone depletion

main way to reduce anthropogenic O3 depletion is phasing out and replacing CFCs

montreal protocol (1987)

a global agreement to phase out CFCs from production

solar radiation

not all incoming solar radiation reaches earth's surface

the greenhouse effect

gases in earth's atmosphere trap heat from the sun and radiate it back down to earth

GHG examples

CO2, CH4, N2O, CFCs, HCFCs, HFCs

global warming potential (GWP)

measure of how much a given molecule of gas can contribute to the warming of the atmosphere over a 100 year period, RELATIVE TO CO2

residence time

how long a molecule stays in the atmosphere

infrared absorption

how well the gas absorbs and radiates infrared radiation (IR)

thermal expansion

water molecules move slightly further apart when they're heated, which leads to sea level rising

environmental impacts of sea level rising

flooding of coastal ecosystems like estuaries

human impacts of sea level rising

relocation of coastal human populations

historic climate change

earth's climate has varied over geologic time, largely due to variations in earth's orbit around the sun

how scientists have measured earth's historical temp. and CO2 levels

foraminifera shells, air bubbles in ice cores, 16O vs 18O isotope concentrations in ice

effects of climate change

rising temp, rising sea level, melting of permafrost

impact of global warming on coastal communities

property loss, damage, potential relocation; loss of barrier islands

impact of global warming on atmospheric currents

widening and weakening of hadley cell; weakened, destabilized jet stream

impacts of global warming on marine ecosystems

altered range of marine ecosystems; altered ranges for organisms

impact of global warming on ocean circulation

suppression of thermohaline circulation

unequal global warming

polar regions of earth are warming faster than other regions (polar amplification)

melting of permafrost

permanently frozen tundra soils that begin to thaw and release methane and CO2 from anaerobic decomposition

impact of global warming on polar ecosystems

arctic sea ice loss = habitat loss

atmospheric warming = ocean warming

as the atmosphere warms, heat is transferred to the ocean

effects of ocean warming on marine species

warmer water holds less O2, causing respiratory stress or suffocation

ocean acidification

increased CO2 in atmosphere = increased ocean CO2 (direct exchange)

calcium carbonate and marine organisms

marine organisms that make shells use calcium and carbonate ions to build their calcium carbonate shells (calcification)

anthropogenic causes for ocean acidification

ff combustion, deforestation, and coal/gas combustion

invasive species

species not native to an area, often introduced by human transport

zebra mussel

transported by ship ballast water; aggressive filter feeders, eating algae that many other species rely on; 1 mil. eggs/year; clogs intake pipes

kudzu vine

planted to limit soil erosion in southern US; grows very rapidly; outcompetes antives for sunlight by growing over them; no herbivore control in the US

asian carp

brought in to control algae growth in aquatic farms; escaped to mississippi river; outcompetes native fish for food and space; decreases fishery production and value

emerald ash borer

spread by wood packing materials of ships/planes and firewood; larvae lain in bark, eat their way into phloem; disrupts tree nutrient transport, killing them; expanding range due to global warming

can toad

introduced to eat cane beetles causing sugarcane crop loss in australia; became invasive due to huge appetite; drove declines in other amphibians and small reptiles

pythons (florida)

brought to florida as pets, released into wild by owners; decimated mammal populations in everglades (~90-95%); aggressive hunters with no natural predators

control/removal methods for invasive species

laws preventing transport; removal of hosts; careful boat cleaning and inspection; introduction of nat. pred.; physical removal

how species become endangered

poaching, invasives, special food/habitat needs, climate change

poaching

poachers hunt exotic species for fur, tusks, horns; may also be over harvested or hunted for food; removed from wild and sold as pets

invasives (endangered species)

invasives can outcompete natives for resources

special food/habitat needs (endangered species)

niche specialists are more prone to endangerment due to specific food/habitat needs; less tolerant of changing climate, habitat loss, wildfires, deforestation, urbanization, etc.

climate change (endangered species)

shifts habitat of many species (migration is harder); changes in temp/precip. can occur too rapidly for some species to migrate or adapt

protecting endangered species

poaching prevention, legislation, protect wildlife habitats

CITES

international agreement for countries to set up agencies to monitor import and export of endangered species

endangered species act

US law giving USFWS power to designate species as endangered or threatened, monitor trade, and purchase land critical to these animals

IUCN red list

EX (extinct), EW (extinct in the wild), CR (threatened), EN (threatened), VU (threatened), NT (near threatened), LC (least concern)

interspecific competition

competition for resources amongst members of different species

HIPPCO (human threats to biodiversity)

habitat fragmentation/loss, invasive species, population growth, pollution, climate change, over exploitation

habitat fragmentation

breaking of larger, continuous habitats into smaller, isolated patches (roads, pipelines, agri/urban land use, logging)

metapopulations

isolated, subpopulation connected by habitat corridors

edge effect

where two ecosystems meet and have different characteristics than the middle of each ecosystem

mitigating biodiversity loss

protecting and connecting habitats; sustainable land use; restoring lost habitats