Lecture 12 Climate Change

CLIMATE ACTION Goals

• Goal 13: Take urgent action to combat climate change and its impacts.

Air Pollution

• Definition: Gaseous and particulate contaminants in Earth's atmosphere.

• Types of Pollutants:

  • Primary Pollutants: Direct impact on the environment.

  • Secondary Pollutants: Formed by reactions between primary pollutants.

• Categories:

  • Outdoor Air Pollution: e.g. fine particles from coal, tobacco smoke, ozone.

  • Indoor Air Pollution: e.g. particulates, carbon oxides from household products.

Air Pollution: Sources

• Stationary Sources: Non-moving sources such as factories and power plants.

• Mobile Sources: Moving sources like cars and gas-powered equipment.

• Agricultural Sources: Emissions from farming practices (manure, fertilizers).

• Natural Sources: Erupting volcanoes, wildfires, dust storms.

Common Air Pollutants

• Particulate Matter: Small particles affecting heart and lungs; harmful if 10 micrometers or smaller.

• Carbon Monoxide: Colorless, odorless gas mainly from combustion.

• Ground-level Ozone: Formed from reactions between nitrogen oxides and VOCs in sunlight.

• Sulfur Oxides: From fossil fuel combustion, linked to respiratory effects.

• Nitrogen Oxides: Indicator of air quality, contributes to ground-level ozone.

• Lead: Main sources are vehicles and industries; regulated by EPA.

Indoor Air Quality

• Many people spend 90% of time indoors; indoor air can be more polluted.

• Sick Building Syndrome: Health issues linked to specific buildings.

Ozone Layer

• Definition: Gaseous ozone present in the atmosphere.

• Hazard: Reactive in lower atmosphere; protects from harmful solar radiation in the upper atmosphere.

• Depletion: Caused by chlorofluorocarbons (CFCs) and other ozone-depleting substances.

Ozone Depletion Policies

• CFCs banned in spray cans in 1978; Montreal Protocol (1987) controlled 96 harmful substances.

• Recovery of ozone layer observed; ongoing vigilance required.

Acid Rain

• Definition: Precipitation with higher levels of nitric and sulfuric acids.

• Effects: Acidifies lakes, damages forests, accelerates material decay.

Climate Change Overview

• Climate: Long-term weather patterns affected by natural and human activities.

• Greenhouse Effect: Natural process that traps heat; influenced by GHGs like CO2 and methane.

• Recent Trends: Continued increase in GHGs, influencing temperature and precipitation patterns.

Future Trends in Climate

• Expectations of rising temperatures, changing precipitation, and sea-level rise due to GHG emissions.

• Ocean acidification impacts marine life, particularly coral reefs.

Take Action

• Individuals can reduce GHG emissions through actions at home and work.

• Support climate initiatives locally.

UN Targets by 2030

• Improve resilience to climate-related hazards, integrate climate measures in policies, enhance awareness and funding.

State of Goal (2023)

• Climate change impacts worsening: sea-level rise, increase in temperatures, need for significant GHG reductions.