AP Environmental Science Study Notes: Unit 9 — Global Change

Stratosphere

The layer of the atmosphere approximately 10–30 miles (16–48 km) above Earth, containing the ozone layer.

Ultraviolet Radiation (UV)

High-energy radiation from the sun, categorized into three types: UV-A, UV-B, and UV-C.

UV-A

Low energy ultraviolet radiation that passes through the atmosphere, causing tanning and skin aging.

UV-B

Medium energy ultraviolet radiation that causes sunburns and skin cancer, blocked significantly by ozone.

UV-C

High energy ultraviolet radiation responsible for the formation of ozone, almost entirely blocked by the stratosphere.

Ozone Formation

The natural cycle in the stratosphere involving the conversion of oxygen molecules into ozone.

Chlorofluorocarbons (CFCs)

Anthropogenic compounds used in coolants and aerosol propellants, harmful to the ozone layer.

The Chemical Process of Ozone Depletion

A sequence involving CFCs breaking down in the stratosphere, leading to ozone layer depletion.

Montreal Protocol (1987)

A global treaty that phased out the production of CFCs and HCFCs to protect the ozone layer.

Hydrofluorocarbons (HFCs)

Substitutes for CFCs that do not deplete ozone but act as greenhouse gases.

Greenhouse Effect

A natural process that keeps Earth warm enough to support life by trapping heat in the atmosphere.

Greenhouse Gases (GHGs)

Gases that absorb and trap infrared radiation, warming the lower atmosphere.

Carbon Dioxide (CO2)

A greenhouse gas produced by burning fossil fuels, deforestation, and decomposition.

Methane (CH4)

A potent greenhouse gas emitted from livestock and decomposing organic matter.

Nitrous Oxide (N2O)

A greenhouse gas primarily produced by agricultural fertilizers and manure management.

Ozone Depletion Effects on Human Health

Increased rates of cataracts, skin cancers, and immune system suppression.

Ecosystem Damage from UV-B

Increased UV-B radiation damages plant tissues and disrupts aquatic food webs.

Climate Change Causes

Factors leading to global warming, including human activity and greenhouse gas emissions.

Antarctic Ice Core Data

Historical data linking CO2 levels with global temperatures over the last 800,000 years.

Population Displacement (Climate Refugees)

Migration forced by rising sea levels and extreme weather caused by climate change.

Thermal Expansion

The increase in water volume caused by warming oceans, contributing to sea level rise.

HIPPCO

An acronym for the main drivers of biodiversity loss: Habitat loss, Invasive species, Population growth, Pollution, Climate change, Overexploitation.

Habitat Fragmentation

The process of breaking large habitats into smaller patches, harming species dependent on core habitats.

Invasive Species Characteristics

Characteristics of invasive species include a high reproductive rate, broad diet, and fast dispersal.

Mechanical Control of Invasive Species

Physical methods of removal such as hunting or pulling weeds.

Chemical Control of Invasive Species

Use of herbicides or pesticides, which may harm non-target species.

Habitat Loss

The primary cause of species extinction, often due to human activities such as deforestation.

Endangered Species Act (ESA)

A U.S. law that protects threatened and endangered species and their habitats.

CITES

The Convention on International Trade in Endangered Species aimed at protecting threatened species.

Kyoto Protocol

An international treaty aiming to reduce greenhouse gas emissions.

Paris Agreement

An international agreement to limit global warming to below 2°C.

Ocean Acidification

The process where the ocean absorbs CO2, lowering pH and affecting marine life.

Carbonic Acid Formation

When CO2 dissolves in water, it forms carbonic acid leading to ocean acidification.

Dissociation of Carbonic Acid

The breakdown of carbonic acid into hydrogen ions and bicarbonate.

Impact of H^+ Ions

Increased hydrogen ions lower pH and interfere with calcifying organisms' ability to build shells.

Zebra Mussels

Invasive species in the Great Lakes that outcompete native species and clog pipes.

Cane Toads

A harmful invasive species introduced in Australia that caused ecological disruption.

Lionfish

An invasive predator in the Caribbean with no natural enemies, harming local ecosystems.

Generalists (Invasive Species)

Species that are adaptable and thrive in new environments, often at the expense of native species.

Biological Control of Invasive Species

Introducing natural predators to control invasive species populations, with high risk of becoming invasive themselves.

Climate Change Feedback Loops

Processes like ocean warming releasing CO2 back into the atmosphere, amplifying climate change effects.

Coral Bleaching

A stress response in corals to temperature increases, leading to loss of symbiotic algae.

Timing Mismatches in Ecosystems

Phenological mismatches such as flowers blooming before pollinators are active, disrupting ecosystems.

Biodiversity Loss Indicators

Habitat loss, invasive species presence, and pollution as indicators of ecosystem health.

Greenhouse Gas (GHG) Global Warming Potential (GWP)

A measure indicating how much heat a gas traps relative to CO2 over a specified time.

Chemical Pollution

Includes oil spills, pesticides, and microplastics negatively affecting ecosystems.

Ozone Depletion vs. Climate Change

Ozone depletion refers to increased UV exposure, while climate change refers to trapped IR heat.