Key environmental challenges in the contemporary world.pptx

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.