Climate Change

1. What is Climate? What is Climate Change?

  • Weather vs. Climate:

    • Weather: Temporary atmospheric conditions (e.g., daily rain, heat).

    • Climate: Long-term averages of weather patterns (e.g., "tropical climate").

  • Climate Change Definition (NASA):
    Long-term shifts in average weather patterns defining Earth’s local/global climates.

2. Greenhouse Effect & Greenhouse Gases (GHGs)

  • Greenhouse Effect:
    Heat from Earth’s surface is trapped by GHGs (e.g., CO₂, CH₄) instead of escaping to space, warming the planet.

  • Key GHGs: Carbon dioxide (CO₂), methane (CH₄), chlorofluorocarbons (CFCs).

3. Evidence of Climate Change

Is the Climate Changing?

  • YES. Key evidence:

    • Arctic sea ice decline (extent/thickness).

    • Sea-level rise (thermal expansion + ice melt).

    • Extreme weather events (hurricanes, droughts).

    • Proxy data (tree rings, ice cores) show unprecedented recent warming.

Is It Caused by Humans?

  • YES. Evidence:

    • Correlation between industrial GHG emissions and temperature rise.

    • Scientific consensus (IPCC) identifies human activity as the primary driver since the 20th century.

4. Impacts of Climate Change

  • Environmental:

    • Polar ice melt → sea-level rise.

    • Biodiversity loss (coral bleaching, extinctions).

    • Increased wildfires.

  • Societal/Economic:

    • Displacement due to flooding.

    • Agricultural disruption (droughts).

    • Health risks (heatwaves, disease spread).

5. Addressing Climate Change

Global Efforts:

  • IPCC (UN): Assesses climate science but does not enforce policies.

  • UNFCCC (COP Meetings):

    • Kyoto Protocol (1997): Failed U.S. ratification.

    • Paris Agreement (2016): Voluntary emissions targets (enforcement challenges).

Challenges:

  • Tragedy of the Commons (see below).

  • Geopolitical disputes over responsibility/funding.

6. Tragedy of the Commons (TOTC) & Climate Change

  • Definition: Overuse of shared, unmanaged resources (e.g., atmosphere) by individuals acting in self-interest, leading to collapse.

  • Solutions (Ostrom’s Principles):

    1. Clear group boundaries.

    2. Localized rules.

    3. Community participation in rule-making.
      (See slide for full list.)

  • Application to Climate Change:

    • Atmosphere is the "ultimate commons" — hard to manage globally.

    • Lack of enforceable rules leads to free-riding (e.g., nations avoiding emissions cuts).