Unit 9: Global Change (APES)

Climate change

a long-term shift in global or regional climate patterns often linked to increased greenhouse gases

global warming

the recent ongoing rise in global average temperature near Earth’s surface due to the increase of GHGs in the atmosphere

Greenhouse gases

such as CO₂, CH₄ (methane), N₂O (nitrous oxide), and H₂O vapor that trap heat in the atmosphere.

Greenhouse effect

the warming effect the results when solar radiation is trapped by the atmosphere

Carbon DIoxide

• CO₂

• a greenhouse gas released by burning fossil fuel and deforestation

Methane

• CH₄

• a potent greenhouse gas from livestock,landfills, and natural gas production

Nitrous oxide

• N₂O

• emitted from agricultural fertilizers and fossil fuels

• a greenhouse gas that contributes to ozone depletion and global warming

ozone layer

• the layer in the atmosphere that absorbs most of the Sun's harmful ultraviolet radiation, protecting living organisms on Earth.

• located in the stratosphere

ozone depletion

the thinning of the one layer caused by CFCs and other ozone-depleting substances

Chlorofluorocarbons

• CFCs

• human-made chemicals that destroy

Montreal Protocol

an international treaty that phased out ozone-depleting substances

UV Radiation

harmful ultraviolet light from the sun hat can cause skin cancer and damage DNA

Ocean warming

the rise in temperature of the ocean due to increased GHGs

coral bleaching

occurs when corals expel algae (zooxanthellae basically chlorophyll for corals) due to stress (HEAT), turning white and becoming weak

ocean acidification

CO₂ dissolving in seawater lowers the pH, affecting marine organisms like corals and shellfish

rising sea level

Caused by melting glaciers and thermal expansion of water due to global warming, resulting in increased flooding and loss of coastal habitats.

thermal expansion

The increase in volume of water as it warms.

invasive species

• a non-native species that disrupts local ecosystems

• they spread rapidly

• usually r-selected species

biodiversity loss

a decline in the variety of life in a particular habit or Earth as a whole

endngered species

a species at risk of extinction

habitat fragmentation

the process by which habitat loss results in the division of large, continuous habitats into smaller, isolated remnants

• this usually happens from anthropogenic events, like when highways or cities are built

• leads to edge effect

Kyoto Protocol

• 1997

The first international treaty that required developed countries to reduce GHG emissions based on their historical contributions. HOWEVER, it was not signed by all counries, so there was no real way to enforce it.

desertification

the overall degradation of land in arid, semi-arid, and dry humid areas due to overgrazing, deforestation, poor agricultural practices, and climate change

• it reduces soil health and fertility

• threatens food security and agricultural yield

• leads to migration and increased competition

Deforestation

the large-scale removal of trees from forests for agriculture, logging, or urban development

• reduces biodiversity

• excess runoff and soil erosion

• loss of nutrients in soil

• habitat loss

• releases the carbon into the atmosphere (forests are a carbon sink)

Overfishing

the depletion of fish stocks by harvesting at rate faster than fish can naturally reproduce or define the replacement fertility rate

• changes in food eb dynamics

• loss in business

ecological footprint

a measurement of how much land and water area a person or society uses to produce the resources they consume and absorb the waste they generate

• quantifies human impact and our resource demands

Tragedy of the Commons

a hypothetical situation in which individuals use shared resources for personal gain, leading to overuse and eventually, a total depletion in said resource. Examples include:

• overgrazing on public lands

• overfishing

• deforestation/ clear cutting

Paris Agreement

• 2015

• A global climate agreement in which nearly all countries pledged to limit global temperature rise to well below 1.5°C

• It uses nationally determined contributions that are reviewed and strengthened over time

• Includes both developed and developing countries

Mitigation

efforts to reduce or prevent the emission of greenhouse gases o slow the ace of climate change. Examples include:

• switching to renewable energy

• improving energy efficiency

• reforestation

• carbon capture and storage

Adaptation

adjusting human or ecological systems in response to climate change to minimize harm. Examples include

• building flood defenses

• planting drought-resistant crops

• revising infrastucture codes for extreme weather

Habitat corridors

protected strips of land that connect separate wildlife habitats, allowing animals to migrate, disperse, and maintain genetic diversity

Edge effect

When a habitat becomes fragmented (like when forests are broken up by roads or agriculture), the amount of edge increases relative to interior habitat. These edges often have different environmental conditions (such as light, temperature, and wind) compared to the interior, which can significantly affect biodiversity.