EVS lec 5

Ocean Acidification

  • Ocean acidification occurs due to increased levels of atmospheric carbon dioxide (CO2).

  • CO2 dissolves in ocean water, forming carbonic acid (H2CO3), which dissociates to bicarbonate (HCO3-) and hydrogen ions (H+).

  • This chemical reaction affects marine life, particularly organisms that rely on calcium carbonate (CaCO3) for their shells and skeletons, such as shellfish and corals.

Impact of Ocean Acidification

  • The main impact is comparable to human osteoporosis, leading to weakened shells in marine organisms.

  • The rate of ocean acidification is currently ten times faster than at any point in the last 55 million years.

  • The ocean absorbs approximately 24 million tonnes of CO2 daily, leading to an expected 170% increase in acidity by 2100 based on high CO2 emission scenarios.

Greenhouse Effect

  • Greenhouse gases (GHGs) absorb and emit infrared radiation, warming the Earth's atmosphere.

  • Without GHGs, Earth's surface temperature would be about 33 °C (59 °F) colder.

  • The most abundant GHGs include:

    • Carbon dioxide (CO2)

    • Methane (CH4)

    • Nitrous oxide (N2O)

    • Ozone (O3)

    • Water vapor (H2O)

Greenhouse Gas Emissions by Sector

  • Industrial Processes: 16.8%

  • Power Stations: 21.3%

  • Transportation Fuels: 14.0%

  • Waste Disposal and Treatment: 3.4%

  • Agriculture: 12.5%

  • Land Use and Biomass Burning: 10.0%

  • Residential, Commercial, Processing, and Distribution: 11.3%

  • Fossil Fuel Retrieval: 10.3%

Example of the Greenhouse Effect

  • The phenomenon is likened to a car's windshield trapping heat, preventing it from escaping, thus warming the interior.

Maintaining Earth’s Temperature

  • Greenhouse gases are crucial for ecosystem health, protecting plant life and maintaining biodiversity.

Causes of the Greenhouse Effect

  • Includes greenhouse gas emissions, ozone layer depletion, and cloud formation.

Disadvantages of Greenhouse Gas Accumulation

  • Increase in Earth’s Average Temperature: Leading to climate change.

  • Rise in Sea Level: Threatening coastal ecosystems and communities.

  • Melting of Snow and Glaciers: Disrupting water supply and ecosystems.

  • Extinction of Plant and Animal Species: Reducing biodiversity.

  • Struggles for Existence: Impacting both wildlife and human populations.

Temperature Variation in the Past 1,100 Years

  • Analysis of historical data shows fluctuations in surface temperatures over the past millennium.

Role of Students in Environmental Conservation

  • Forming local student unions to enhance involvement in environmental issues.

  • Conducting afforestation programs in urban areas to restore greenery.

  • Creating effective protection campaigns by including students from diverse ecological regions.

Health Effects Due to Environmental Changes

  • Increase in temperature and pollution directly impacts human health by disrupting natural cycles.

  • Water scarcity and quality issues lead to health problems including diseases from contaminated water.

Future Consequences

  • Persistent environmental issues such as ozone layer depletion and greenhouse gas accumulation can adversely affect life on Earth.

Ozone Layer Depletion

  • Ozone layer absorbs most UV radiation, vital for protecting life on Earth.

  • Compounds like Chlorofluorocarbons (CFCs) contribute to ozone layer degradation.

Environmental and Health Effects of Ozone Depletion

  • Increased UV-B radiation leads to health issues like skin cancer and cataracts.

  • Damage to crops and forests, affecting food security.

  • Declines in biodiversity as ecosystems are disrupted.

Acid Rain: Definition and Impact

  • Acid rain is precipitation that is significantly more acidic than normal due to pollutants.

  • Has detrimental effects on aquatic environments, soil quality, and structures such as the Taj Mahal.

Water Scarcity in India

  • Water scarcity affects 2.8 billion people worldwide, with many lacking access to clean drinking water.

  • Contributing factors include population growth, climatic change, water pollution, and inefficient use of resources.

Cases of Water Scarcity

  • Waterborne diseases are significant contributors to child mortality; a vast number lose their lives annually due to unsafe water.

  • Strategies for water conservation include efficient usage and recycling of water in agriculture and domestic contexts.