Environment

1. Key environmental challenges in
the contemporary world
Instructor: Beenish Fatima

2. Environmental Problems: Introduction
• Global Issue: Environmental problems affect
water, air, land, and animals worldwide.
• Human Impact: Water pollution and
deforestation for timber or agriculture.
• Loss of topsoil replaced by harmful chemicals.
• Air contamination with pollutants.

3. Nature of Environmental Problems
• Human-Environment Interconnection:
 Dynamic relationship between living beings and their physical
environment.
 Balance in natural cycles is essential for life’s continuity.
• Impact of Human Activities:
 Habitat destruction and resource exploitation disrupt natural
cycles**.
 Unsustainable practices threaten long-term survival.
• The Warning:
 Unchecked environmental damage could reach irreversible levels.
 Examples: Global warming, biodiversity loss, and resource
depletion.

4. • natural cycle**:
The natural cycles of the environment are the processes
that continuously move elements between the air, water,
soil, and living things. E.g. Water cycle, Carbon cycle etc.
• How human activities impact natural cycles:
Human activities like burning fossil fuels and
deforestation have changed the carbon cycle
This has led to increased levels of carbon dioxide in the
atmosphere, which has caused global temperatures to
rise

5. Major Global and National Environmental
Problems
• Types of Environmental Problems:
 Local: Pollution and resource degradation at the community
level.
 National: Widespread deforestation, water scarcity, and
industrial pollution.
 Global: Climate change, ozone depletion, and ocean pollution.
• Emerging Threat: Environmental Warfare
 Deliberate actions like bombardments that destroy ecosystems.
 Impact: Irreparable damage to land, water, and air, threatening
entire populations.

6. 1-Pollution
• Pollution is the accumulation and adverse effects of
pollutants on human health, welfare, and the
environment.
• Sources of Pollution:
 Natural processes e.g. Smoke from natural fires.
 Human Activities:
– Waste from mining, agriculture, and industrial activities.
– Fossil fuel burning → Increased carbon dioxide → Global
warming.
– Poor waste management → Pathogenic microorganisms in
water.

7. 2- Global Warming
• The observed and projected increase in the Earth's average
temperature in its atmosphere and oceans.
• The global average surface temperature rose 0.6 to 0.9 degrees
Celsius (1.1 to 1.6°F) between 1906 and 2005, and the rate of
temperature increase has nearly doubled in the last 50 years
(NASA Earth Observatory)
• Causes of Global Warming:
 Greenhouse Gases:
– Carbon dioxide and water vapor trap heat from the Earth's surface.
– These gases prevent infrared radiation from escaping into space.
 Human Activities:
– Fossil fuel burning.
– Deforestation reducing carbon absorption.
• Impacts of Global Warming: Melting ice sheets and glaciers,
rising sea levels

8. 3-Ozone Depletion
• The gradual thinning of the Earth's ozone layer in the stratosphere caused by
chemical pollutants. (ozone layer acts as a shield, protecting life on Earth from
harmful ultraviolet (UV) radiation)
• Causes of Ozone Depletion:
 Chlorofluorocarbons (CFCs):
– Found in refrigerants, aerosol sprays, and solvents.
– Break down ozone molecules in the atmosphere.
 Halons:
– Used in fire extinguishers, contributing to ozone layer damage.
 Nitrous Oxide:
– Released by agricultural and industrial activities.
• Impacts of Ozone Depletion:
 Health Effects:
– Increased UV radiation causes skin cancer, cataracts, and immune system suppression.
 Environmental Effects:
– Affects plant growth and marine ecosystems.

9. 4-Land Degradation
• A global issue where the biophysical environment deteriorates due to
human-induced processes.
• Temporary or permanent decline in the productive capacity of land.
• Affects resources like soil, water, vegetation etc.
• Impacts of Land Degradation:
 Decline in agricultural productivity.
 Loss of valuable ecosystems and biodiversity.
 Increased vulnerability to natural disasters (e.g., floods, droughts).
 Negative economic and social effects on communities reliant on land.
• Causes of Land Degradation:
 Overgrazing, deforestation, and poor farming practices.
 Urbanization and industrial activities.
 Climate change and extreme weather events.

10. 5-Climate Change
• Climate change refers to the long-term shifts in temperature,
precipitation, wind patterns, and other elements of the Earth's climate
system.
• Rising emissions of carbon dioxide (CO₂) and other greenhouse gases are
causing the Earth's temperature to increase, leading to global warming.
• Difference Between Climate and Weather:
 Weather: Short-term atmospheric conditions (e.g., rain, temperature,
wind).
 Climate: Long-term average weather patterns in a region over 30+ years.
• Impacts of Climate Change:
 Rising Global Temperatures
 Melting glaciers and rising sea levels.
 Increased frequency of extreme weather events (hurricanes, droughts).
 Disruption of ecosystems and biodiversity loss.
 Threats to food security and water resources.