Pollution and Greenhouse Gases

Pollution and Greenhouse Gases

Lecture Overview

• Definition of Pollution

• Water Pollution

  • Sources and Types

  • Pollution Prevention

• Air Pollution

  • Historic Trends

  • Impacts and Significance

  • Current and Future Issues

Definitions of Pollution

• Dictionary Definitions:

  • Pollution is described as an "undesirable state of the natural environment being contaminated with harmful substances as a consequence of human activities."

  • It is also defined as the "contamination of soil, water, or the atmosphere by the discharge of harmful substances."

Sources of Pollution

• Major categories:

  • Sewage and Water Works

  • Waste Management

  • Industry

  • Domestic and Residential

  • Agriculture

  • Transport

Water Pollution

Sources of Water Pollution

• Pollution can occur in oceans, rivers, streams, lakes, and groundwater.

• Major Sources of Water Pollution:

  • Agriculture

  • Industry

  • Sewage and Water Works

• Statistics: In the UK, agriculture was responsible for 150 water pollution incidents in 2002 (EA, 2002).

Point and Non-Point Sources

• Point Pollution:

  • Defined as pollutants released directly into a body of water.

  • Example: Oil spills

• Non-Point Pollution:

  • Pollutants are delivered indirectly, often through environmental changes.

  • Example: Fertilizers carried into streams by rain/runoff

Types of Water Pollution

• Various forms of pollutants include:

  • Chemical wastes

  • Heavy metals

  • Organic waste

  • Sediments

  • Pathogens

  • Oil

  • Radioactive wastes

  • Heat

Environmental and Health Impacts

• Chemical contamination can lead to severe consequences for wildlife and human health, including:

  • Death to wildlife or reproductive disorders

  • Bio-accumulation of heavy metals in fish causing health issues upon human consumption

  • Toxicity of oil affecting aquatic life and leading to suffocation

  • Suspended solids affecting light penetration and altering habitats due to sedimentation

Eutrophication

• The influx of excess nutrients or organic matter into water bodies results in eutrophication.

• Example Sources: Fertilizers, detergents, sewage

Effects of Eutrophication

• Leads to:

  • Increased algal and microbial production

  • Reduction of water clarity, which negatively affects plant growth

  • Lower oxygen concentrations, which diminishes invertebrate and fish life

Water Pollution Issues

• Issues related to water pollution include:

  • Shortages of safe, clean drinking water in various regions

  • Waterborne diseases stemming from a lack of treatment plants

  • Industrialization contributing to declining water quality

  • Groundwater contamination leading to stress on water supply

  • Acidification of surface waters due to air pollution

Preventing Water Pollution

• Legislation: Main tool for controlling water pollution

• Techniques: Encouragement to think of additional methods for prevention

Treatment Examples

• Planting Rushes: Used for treating coal mining discharge

Air Pollution

Sources of Air Pollution

• Major sources include:

  • Transport

  • Power and Heat Generation

  • Burning of Solid Wastes

  • Industrial Processes

• Examples of Air Pollutants: Carbon Dioxide, Methane, CFCs, among others

Carbon Dioxide (CO2)

• Atmospheric CO2 levels have risen since the Industrial Revolution:

  • Pre-Industrial Levels (before 1750): 280 ppm

  • Current Levels: 400 ppm

  • Predicted Levels by 2050: 600 ppm

• Documented through observations at the Mauna Loa Observatory in Hawaii.

CO₂ Concentration Trends

• Reference graph shows the increase in atmospheric CO2 from 1970 to 1995 with periodic evaluations.

The Greenhouse Effect

• Describes how certain gases trap heat in the atmosphere, contributing to global warming and climate change.

Other Important Greenhouse Gases

• Methane (CH4):

  • Characterized as a highly active greenhouse gas.

  • Atmospheric Concentrations:

  • Pre-Industrial (before 1750): 700 ppb

  • Current: 1900 ppb

  • Major contributors include livestock, landfills, inundated lands, and permafrost

The Kyoto Protocol

• Ratified by 186 countries aiming to reduce emissions by 5.2% under 1990 levels by 2010, with the UK's commitment set at 12.5%.

• The USA, China, and India have separate agreements.

• Implementation of the Emissions Trading Scheme is a market-based instrument where emissions are treated as currency.

• The government White Paper entitled "Our Energy Future: Creating a low carbon economy" denotes strategic directions toward emission reductions.

Chlorofluorocarbons (CFCs)

• CFCs rise into the stratosphere and engage in chemical reactions that adversely affect ozone levels.

• Atmospheric Concentrations:

  • Pre-Industrial: 0 ppb

  • Current: 4 ppb

• They act as effective greenhouse gases, having a prolonged atmospheric lifespan.

• Commonly used as refrigerants and propellants.

Ozone Depletion

• The ozone layer in the stratosphere protects against harmful UV-B radiation.

• Breakdown of this layer leads to notable impacts on:

  • Human health (e.g., increased risk of skin cancer)

  • Plant growth (e.g., effects of UV-B on DNA and proteins)

  • Wildlife, such as birds and insects that are sensitive to UV radiation

  • Climate change overall

Montreal Protocol

• Established in 1987 to eliminate ozone-depleting substances highlighting significant international cooperation.

• Achievements include global elimination of harmful substances and cooperation among developed and developing nations.

• Procedures enforce the phasing out of production and consumption of CFCs alongside strict disposal procedures (e.g., for refrigerators).

• Alternatives to CFCs include HFCs, PFCs, and SF6.

Examples of Other Air Pollutants for Further Research

• Sulphur and Nitrous Oxides

• Particulate Matter

• Volatile Organic Compounds

• Carbon Monoxide

• Ground-Level Ozone

• Lead