APES UNIT 9 STUDY GUIDE

- HCFCs replacing CFCs (the cons + pros) of both 

-HCFCs replace CFCs, have %90 -95 less ozone depletion 

- HCFCs are used in refrigeration + air conditioning and have shorter 

and have a shorter life but high GWP (global warming potential). 

- CFCS  lead to Ozone Hole in SOUTHH POLE

- primary cause of ozone depletion  The primary cause of ozone depletion is the release of chlorofluorocarbons (CFCs) and other ozone-depleting substances (ODS) into the atmosphere. - **Chlorofluorocarbons (CFCs):** These man-made compounds were widely used in refrigeration, air conditioning, foam production, and aerosol propellants due to their stability and non-flammability. However, once released into the atmosphere, they eventually rise to the stratosphere, where they are broken down by ultraviolet (UV) radiation, releasing chlorine atoms that catalyze the destruction of ozone molecules. - **Ozone Layer:** The ozone layer is a region of the Earth's stratosphere that contains a high concentration of ozone (O₃) molecules. It plays a crucial role in protecting life on Earth by absorbing the majority of the sun's harmful ultraviolet radiation. Depletion of this layer leads to increased UV radiation reaching the Earth’s surface, which can cause skin cancer, cataracts, and harm to wildlife, including negative impacts on aquatic ecosystems and terrestrial plants.

- **Human Impact:** The production and use of these substances increased during the 20th century, leading to significant ozone loss, particularly over Antarctica—referred to as the “ozone hole.”

- **Regulatory Measures:** The introduction of international agreements, such as the Montreal Protocol in 1987, has been successful in phasing out the use of many ozone-depleting substances. As a result, there is evidence that the ozone layer is slowly recovering, but full recovery is still decades away.

- CFCs + South Pole + UV 

- Global warming potential (GWP) (9.3)
- Definition: GWP quantifies how much heat a greenhouse gas retains in the atmosphere compared to CO₂. This measure considers both the gas's effectiveness at absorbing heat and its lifespan in the atmosphere.

- Factors Influencing GWP:
- Heat Absorption Capability: Some gases are more effective than CO₂ at trapping heat due to their molecular structure.
- Atmospheric Lifetime: GHGs that persist longer in the atmosphere have a higher GWP than those that break down quickly.

- Common GHGs and Their GWPs:
- Methane (CH₄): GWP of approximately 28-36 times that of CO₂ over 100 years. It is emitted from agricultural practices, landfills, and fossil fuel extraction.
- Nitrous Oxide (N₂O): GWP of about 298 times CO₂. It is released from agricultural and industrial activities, as well as during the combustion of fossil fuels and solid waste.
- Fluorinated Gases: These gases, including hydrofluorocarbons (HFCs) and perfluorocarbons (PFCs), can have extremely high GWPs, sometimes thousands of times greater than CO₂, making them significant contributors to global warming despite being present in smaller quantities.

- Importance of GWP: Calculating GWP is essential for climate change policies as it helps in evaluating the impacts of different GHGs and prioritizing actions to reduce emissions. It also enables the creation of more targeted regulations and initiatives aimed at minimizing the overall greenhouse gas emissions, thus aiding efforts to combat climate change effectively.

- Highest is CFC/Chlorofluorocarbons

- Relation of Metabolism in Marine Species + Dissolved Oxygen 

- Metabolic is directly related with ocean temp. As the ocean warms the faster the metabolism. Oxygen cannot dissolve in warm water as in cold water, they’re inversely related 

- Ocean acid in relation to coral reefs

-     Ocean acidification reduces the carbonate ions dissolved in the ocean which makes coral reeds not be able to build their skeletons 

- Promoting biodiversity

- 9.10 

- Cultural Ecosystems 

- hiking, birdwatching, biodiversity makes a green space which can lead to spiritual connections among some religions. 

- Infrared v.s UltraViolet (9.3)

        -    Infrared Light (IR)
  - Primarily contributes to warming of the Earth's atmosphere and surface, playing a crucial role in the greenhouse effect.
  - Does not cause direct harm to biological tissues; its primary impact is thermal, affecting temperature regulation in ecosystems.

  • Ultraviolet Light (UV)
      - Causes chemical changes in the environment, including DNA damage in living organisms and significant impacts on plant life.
      - Contributes to ozone layer depletion, leading to increased UV radiation reaching the Earth's surface, thus affecting human health and ecosystems.