Stratospheric Ozone, Greenhouse Effect, and Biodiversity

These flashcards cover stratospheric ozone depletion, the greenhouse effect, global climate change impacts, and threats to biodiversity as detailed in the lecture transcript.

Stratospheric Ozone

Ozone in the stratosphere that absorbs all $UV-C$ and much of $UV-B$ radiation, protecting life from tissue damage and DNA mutation.

Chlorofluorocarbons (CFCs)

A primary anthropogenic cause of $O_3$ breakdown, historically used as refrigerants and propellants in aerosol containers.

Photolyzation (Chlorine)

The process where solar radiation breaks $Cl_2$ into two free chlorine atoms; a single $Cl$ atom can destroy up to 100,000 ozone molecules.

Polar Stratospheric Clouds (PSC)

Clouds made of water and nitric acid ($HNO_3$) that form above Antarctica when temperatures reach $-100^{\circ} F$, facilitating natural ozone depletion.

Montreal Protocol (1987)

A global agreement to phase out the production of $CFCs$ in refrigerators, aerosols, and other industrial uses.

Hydrofluorocarbons (HFCs)

A replacement for $HCFCs$ that does not deplete the ozone layer because it lacks chlorine, although it is still a strong greenhouse gas.

Greenhouse Effect

The process where greenhouse gases absorb infrared radiation released by Earth's surface and radiate it back toward Earth, maintaining surface temperatures necessary for life.

Global Warming Potential (GWP)

A measure based on residence time and infrared absorption that compares how much a molecule of gas contributes to warming over 100 years relative to $CO_2$.

Albedo

The ability of a surface to reflect solar radiation; high albedo surfaces reflect sunlight, while low albedo surfaces absorb it and release infrared radiation.

Thermal Expansion

The phenomenon where water molecules move slightly further apart as they are heated, leading to a rise in sea levels.

Disease Vectors

Living organisms, such as mosquitoes, ticks, or fleas, that transmit diseases like malaria, Zika, and West Nile from animals to humans.

Milankovitch Cycles

Predictable variations in Earth's climate caused by changes in its orbital eccentricity ($100,000$ years) and obliquity ($40,000$ years).

Foraminifera Shells

Evidence used by scientists to estimate historical temperatures based on the temperature tolerance of different species found in ocean sediments.

Thermohaline Circulation

A global ocean current that redistributes heat, salt, and nutrients; its suppression by freshwater melt from Greenland can cool Europe.

Polar Amplification

The phenomenon where polar regions warm faster than other regions due to factors like lower albedo from melting ice and the transport of tropical heat.

Coral Bleaching

A condition occurring when ocean warming or pollutants cause corals to expel their mutualistic photosynthetic algae (zooxanthellae).

Ocean Acidification

The decrease in ocean $pH$ caused by increased atmospheric $CO_2$, which reacts with water to form carbonic acid ($H_2CO_3$).

Calcification

The process by which marine organisms use calcium ($Ca^{2+}$) and carbonate ($CO_3^{2-}$) ions to build shells; it is hindered by the increase of $H^+$ ions in acidified oceans.

Invasive Species

Non-native species, often $r$-selected generalists with no natural predators, that outcompete native species for resources in a new habitat.

Zebra Mussel

An invasive species in the US transported by ship ballast water that clogs intake pipes and outcompetes native species for algae.

CITES

An international agreement for countries to monitor the import and export of endangered species as specified by the IUCN Red List.

HIPPCO

An acronym for the main factors decreasing biodiversity: Habitat destruction, Invasive species, Population growth, Pollution, Climate change, and Overexploitation.

Edge Effect

The phenomenon where the boundary between two ecosystems has different characteristics and often higher biodiversity than the middle of either ecosystem.

Metapopulations

Mostly isolated subpopulations created by habitat fragmentation that may be connected by habitat corridors to allow for gene flow.