Global Change Review Notes

Kyoto Protocol

  • An international treaty that commits its parties to reduce greenhouse gas emissions, based on the premise that global warming exists and human-made CO2 emissions have caused it.

  • Adopted in 1997 and entered into force in 2005.

  • Aims to stabilize GHG concentrations in the atmosphere.

Montreal Protocol

  • An international treaty designed to protect the ozone layer by phasing out the production of numerous substances that are responsible for ozone depletion.

  • Signed in 1987, it successfully led to a reduction in CFCs and other ozone-depleting substances.

The Keeling Curve

  • Represents the concentration of CO2 in Earth's atmosphere since 1958.

  • Y-axis: CO2 levels (measured in parts per million, ppm)

  • X-axis: Years (time)

  • Important for demonstrating the increase of CO2 and implying correlation with global warming.

Major Greenhouse Gases (GHGs)

  • Carbon Dioxide (CO2): Produced by fossil fuel combustion, respiration; contributes significantly to the greenhouse effect.

  • Methane (CH4): Comes from agriculture (e.g., livestock), landfills; has a much higher GWP than CO2.

  • Nitrous Oxide (N2O): Result of agricultural and industrial activities; potent greenhouse gas.

  • Fluorinated gases: Synthetic gases used in various industrial applications; can trap heat much more efficiently than CO2.

  • Excess of GHGs leads to enhanced greenhouse effect, resulting in climate change, extreme weather events, and other environmental impacts.

Global Warming Potential (GWP)

  • A measure of how much a given mass of greenhouse gas contributes to global warming relative to the same mass of CO2 over a specified time (usually 100 years).

GWP Comparison of Major GHGs

  • CO2: GWP of 1 (baseline)

  • Methane (CH4): GWP of 28-36 over 100 years.

  • Nitrous Oxide (N2O): GWP of 298.

  • Fluorinated gases: Extremely high GWPs, ranging from thousands to tens of thousands.

Anthropogenic GHG

  • Carbon Dioxide is the primary GHG that comes from anthropogenic sources (fossil fuel combustion).

Chlorofluorocarbons (CFCs)

  • Synthetic compounds used as refrigerants, propellants, and solvents; highly effective in ozone depletion.

  • CFCs have been largely phased out due to Montreal Protocol.

Advantages and Disadvantages of CFC Alternatives

  • HCFs (Hydrochlorofluorocarbons): Less harmful to ozone, but still potent GHGs.

  • HFCs (Hydrofluorocarbons): No ozone depletion potential but significant global warming potential.

  • HC (Hydrocarbons): Natural, low toxicity, low GWP but flammable and less efficient.

Greenhouse Effect

  • The process by which GHGs trap heat from the Earth's surface, keeping the planet warm enough to sustain life.

  • Natural process but intensified by human emissions leading to climate change.

Ocean Acidification

  • Increase in CO2 absorption by the oceans leading to lower pH levels.

  • Causes: CO2 emissions from fossil fuels, deforestation.

  • Effects: harming marine life, especially organisms with calcium carbonate shells (e.g., coral reefs, shellfish).

Environmental Effects of Ozone

  • Stratospheric Ozone: Protects against UV radiation; depletion leads to increased UV levels impacting health and ecosystems.

  • Tropospheric Ozone: Harmful air pollutant; can cause respiratory issues and crop damage.

Human Health Impacts of Ozone Depletion

  • Increased risk of skin cancer, cataracts, and immune system suppression due to heightened UV exposure.

Economic Impact of Ozone Depletion

  • Increased healthcare costs due to UV-related illnesses.

  • Losses in agriculture and fisheries affecting livelihoods.

Scientific Data Supporting Global Warming

  • Increased frequency of extreme weather events.

  • Rising ocean temperatures and levels.

  • Melting glaciers and diminishing ice sheets.

Mitigating Global Warming

  • Transitioning to renewable energy sources (solar, wind).

  • Enhancing energy efficiency.

  • Reforestation and sustainable land use practices.

Economic Impacts of Global Warming

  • Increased disaster recovery costs.

  • Damage to infrastructure from extreme weather.

  • Shifts in agriculture affecting food supply and prices.

Effects on Human Health

  • Increased heat-related illnesses

  • Expansion of vector-borne diseases (e.g., malaria, dengue).

Effects on Biodiversity/Ecosystems

  • Habitat loss due to changing climate patterns.

  • Species migration and potential extinction due to inability to adapt.

Effects on Water Supplies

  • Changes in precipitation patterns affecting freshwater availability.

  • Increased evaporation rates leading to water scarcity.

Effects on Agriculture

  • Altered growing seasons impacting food production.

  • Pests and diseases may proliferate with warming temperatures.

Effects on Coral Reefs

  • Increased ocean temperatures leading to bleaching.

  • Ocean acidification weakening coral structures.

Sea Level Rise and Global Warming

  • Melting of ice caps contributes to higher sea levels.

  • Thermal expansion of seawater as it warms.

Impact of Sea Level Rise on Coastal Ecosystems

  • Coastal erosion affecting habitats and wildlife.

  • Increased flooding impacting estuarine environments.

Positive Feedback Loops in Global Warming

  • Melting polar ice reduces albedo, leading to increased heat absorption and further warming.

  • Thawing permafrost releases methane, enhancing the greenhouse effect.

Albedo

  • The measure of how much sunlight is reflected by a surface.

  • Ice and snow have a high albedo, while dark surfaces absorb more heat.

Diseases Linked to Climate Change

  • Malaria: Greater prevalence due to expanded mosquito ranges.

  • West Nile Virus: Increased due to warmer temperatures.

  • Cholera: Warming water bodies facilitate bacterial growth.

  • Zika, Plague, Tuberculosis, SARS, MERS, Dysentery: Epidemiological shifts related to changing climates.

Nuclear Power: Advantages and Disadvantages

  • Advantages: Low greenhouse gas emissions, high energy density.

  • Disadvantages: Radioactive waste, risk of catastrophic failure.

Renewable Energy Sources: Pros and Cons

  • Wind: Inexhaustible, eco-friendly but intermittent.

  • Hydroelectric: Reliable, low emissions, but ecological disruption.

  • Hydrogen Fuel Cells: Clean, renewable but expensive production methods.

  • Photovoltaic Solar: Abundant resource, but dependent on weather.

  • Biomass: Reduces waste, but agricultural competition for land.