Class Notes: Climate Change Impact

Table of Contents
1. Introduction to Climate Change
2. Scientific Basis of Climate Change
3. Major Causes of Climate Change
4. Impacts on the Environment
5. Impacts on Human Health
6. Economic Consequences of Climate Change
7. Impact on Agriculture and Food Security
8. Technological and Policy Solutions
9. Future Projections and Challenges
10. Conclusion: The Way Forward

1. Introduction to Climate Change

Climate change refers to long-term shifts in global temperatures and weather patterns,
primarily driven by human activities. While climate variation has occurred naturally over
millions of years, scientific evidence strongly suggests that human actions have
accelerated these changes at an unprecedented rate.

Key Facts About Climate Change:

• The Earth’s average temperature has increased by approximately 1.2°C since the
pre-industrial era (1850-1900).
• The last eight years have been the warmest on record (as of 2024).
• Greenhouse gas (GHG) emissions have reached their highest levels in recorded
history.

Why is Climate Change Important?

Climate change affects weather patterns, sea levels, ecosystems, human health, and
economies, making it a critical global issue that requires urgent attention.
2. Scientific Basis of Climate Change
2.1 The Greenhouse Effect

The greenhouse effect is a natural process that warms the Earth’s surface. However, human
activities have intensified this effect, leading to global warming.

• Major Greenhouse Gases (GHGs):

o Carbon dioxide (CO₂) – from burning fossil fuels.
o Methane (CH₄) – from agriculture and landfills.
o Nitrous oxide (N₂O) – from fertilizers and industry.
o Fluorinated gases – from industrial applications.

Scientific Evidence:

• Ice core data shows that CO₂ levels are at their highest in 800,000 years.
• Satellite observations confirm that the Earth’s heat balance is shifting,
causing more energy to be trapped.

3. Major Causes of Climate Change

3.1 Human-Induced Causes

1. Burning Fossil Fuels (coal, oil, gas) – releases large amounts of CO₂.
2. Deforestation – reduces carbon absorption and increases atmospheric CO₂.
3. Industrialization – leads to emissions from manufacturing and transportation.
4. Agriculture – generates methane from livestock and nitrous oxide from fertilizers.

3.2 Natural Factors (Less Significant Today)

• Volcanic Eruptions – Can cool or warm the planet temporarily.

• Solar Variations – Small changes in solar energy output affect climate but do not
explain current warming trends.

Key Study:
The Intergovernmental Panel on Climate Change (IPCC) reports that human activities are
responsible for over 90% of global warming since the 1950s.

4. Impacts on the Environment

4.1 Rising Global Temperatures

• The Earth’s surface temperature has increased by 1.2°C since 1880.

• Heatwaves are becoming more frequent and intense.
4.2 Melting Ice Caps and Rising Sea Levels

• Arctic sea ice is declining by 13% per decade.

• Greenland and Antarctica are losing ice rapidly, causing sea level rise.
• Rising sea levels threaten coastal cities and low-lying nations.

4.3 Extreme Weather Events

• Increased hurricanes, cyclones, and typhoons.

• More frequent and severe droughts, floods, and wildfires.

Example:
In 2023, extreme heatwaves in Europe and North America broke temperature records and
caused significant economic and health impacts.

5. Impacts on Human Health

5.1 Heat-Related Illnesses

• Increased cases of heat strokes, dehydration, and cardiovascular diseases.

5.2 Air Pollution and Respiratory Issues

• Wildfires and industrial pollution increase asthma, lung infections, and other
respiratory diseases.

5.3 Water and Food-Borne Diseases

• Warmer temperatures lead to the spread of infectious diseases like malaria, dengue,
and cholera.

Scientific Prediction:
The World Health Organization (WHO) estimates that climate change could cause 250,000
additional deaths per year by 2050.
6. Economic Consequences of Climate Change
6.1 Damage to Infrastructure

• Floods and hurricanes damage roads, bridges, homes, and power grids.
• Coastal cities face billions in adaptation costs due to rising sea levels.

6.2 Impact on Global GDP

• Studies suggest that climate change could shrink the global economy by 18% by
2050.

6.3 Increased Costs of Natural Disasters

• The cost of climate-related disasters has risen from $50 billion annually in the
1980s to over $200 billion today.

Case Study:
The 2023 floods in Pakistan displaced 33 million people and caused $30 billion in
damages.

7. Impact on Agriculture and Food Security

7.1 Reduced Crop Yields

• Higher temperatures reduce wheat, rice, and maize production.

7.2 Water Scarcity

• Changing rainfall patterns lead to droughts and irrigation problems.

7.3 Impact on Fisheries

• Ocean warming is reducing fish populations, affecting coastal economies.

Prediction:
By 2050, climate change could reduce global food production by 20%, leading to higher
food prices and famine risks.
8. Technological and Policy Solutions
8.1 Renewable Energy

• Transitioning to solar, wind, and hydroelectric power can reduce emissions.

8.2 Carbon Capture and Storage (CCS)

• Technologies that capture CO₂ from power plants and industries and store it
underground.

8.3 Global Climate Agreements

• The Paris Agreement aims to limit global warming to below 2°C.

• Many countries are committing to net-zero emissions by 2050.

Example:
The EU’s Green Deal plans to cut 55% of emissions by 2030.

9. Future Projections and Challenges

9.1 Climate Models and Predictions

• If emissions continue, global temperatures could rise by 4°C by 2100, causing severe
disruptions.

9.2 Challenges in Climate Action

1. Political resistance – Some nations delay climate policies.

2. Economic concerns – Transitioning to clean energy requires investments.
3. Technological limitations – Renewable energy storage needs improvement.
10. Conclusion: The Way Forward
Climate change is one of the most pressing global challenges. Its impacts are already
visible, and without urgent action, future generations will face severe consequences.

Key Steps for a Sustainable Future:

• Reduce fossil fuel dependence by investing in renewables.

• Strengthen climate policies through international cooperation.
• Promote climate education to raise awareness.

The future of our planet depends on scientific innovation, political will, and global
cooperation.

Final Thought

"We do not inherit the Earth from our ancestors; we borrow it from our children."