Unit 1: Understanding Our Natural World
Theme C: Our Changing Weather and Climate – The Impacts of Extreme Weather
Welcome to your study notes on The Impacts of Extreme Weather! Weather affects our day-to-day lives, but when weather conditions become severe and unusual, they turn into extreme weather hazards. In this topic, you will learn how extreme weather events across the globe cause widespread disruption, damage, and hardship.
Don't worry if case studies and figures seem tricky at first! We will break everything down into clear, easy-to-remember chunks so you can tackle any question in your Unit 1 exam with confidence.
1. What is Extreme Weather?
Extreme weather refers to weather events that are significantly different from the normal, expected weather patterns of an area. These events are often severe, unexpected, and capable of causing serious harm.
The Three Official Hazard Types (Outside the British Isles)
For your CCEA GCSE examination, your case study must be an event that occurred outside the British Isles. The specification allows one of three types of extreme weather hazards:
1. Tropical Storms / Hurricanes (e.g., Hurricane Katrina 2005, Hurricane Sandy 2012, or Typhoon Haiyan 2013)
2. Tornadoes (e.g., Joplin, Missouri Tornado 2011, or Moore, Oklahoma Tornado 2013)
3. Droughts (e.g., California Drought or Sahel Drought)
Did you know? Tropical storms are known by different names depending on where they form: they are called hurricanes in the Atlantic, typhoons in the northwest Pacific, and cyclones in the Indian Ocean and South Pacific. They are all atmospheric weather hazards!
Key Takeaway: Always ensure your chosen case study is an atmospheric weather event located outside the British Isles, not a tectonic event like an earthquake or tsunami.
2. Classifying the Impacts: People vs. Property
In the CCEA exam, questions frequently ask you to distinguish between impacts on people and impacts on property. Dividing your answers into these two categories is essential for earning top marks.
A. Impacts on People (Social / Human Impacts)
These are the direct and indirect effects of the weather event on human life, health, and daily living:
• Loss of life and injury: Fatalities, trauma, and physical injuries caused by flying debris, collapsed buildings, or floodwaters.
• Displacement and homelessness: People forced to evacuate their homes and live in temporary emergency shelters or sports arenas.
• Health crises and disease: Outbreaks of waterborne diseases (such as cholera or dysentery) caused by contaminated drinking water.
• Food and water shortages: Lack of access to clean bottled water and fresh food supplies, which can lead to famine during prolonged droughts.
• Disruption to daily life: Closures of schools, disruption of healthcare in hospitals, and failure of emergency services.
B. Impacts on Property (Structural, Infrastructure & Economic Impacts)
These are the physical damages to the built environment, transport networks, and economic systems:
• Structural damage: Roofs torn off, windows blown in, and the total collapse of homes, offices, and schools caused by high winds or storm surges.
• Infrastructure destruction: Flooded roads, destroyed bridges, severed communication cables, and downed power lines leaving areas without electricity or running water.
• Economic losses and repairs: Huge financial costs to rebuild, insurance claims, loss of business revenue, and the destruction of agricultural crops and farmlands.
Memory Trick: Think of People = Pulse & Pain (lives, injuries, displacement, illnesses) and Property = Pavement & Pockets (buildings, roads, financial costs, repairs).
3. Named Case Study: Hurricane Katrina (August 2005)
Below is a complete, specification-focused case study of an extreme weather event outside the British Isles.
Event Overview and Location
• Date: Late August 2005.
• Location: Gulf Coast of the USA, severely impacting the city of New Orleans, Louisiana, as well as coastal Mississippi.
• Hazard Details: Reached Category 5 over the Gulf of Mexico and made landfall as a powerful Category 3 hurricane on the Saffir-Simpson scale.
• Strength: Sustained wind speeds exceeding 120 mph (195 km/h) and a massive storm surge reaching up to 8.5 metres along parts of the coastline.
Impacts on People (Hurricane Katrina)
• Fatalities: Over 1,800 people lost their lives, mainly due to drowning in floodwaters.
• Emergency Displacement: Tens of thousands of displaced residents who were unable to evacuate were forced to shelter in unbearable conditions inside the Louisiana Superdome and New Orleans Convention Center.
• Homelessness: Hundreds of thousands of people were displaced from their homes across the Gulf Coast.
• Health and Sanitation: Severe shortages of clean drinking water, contaminated floodwaters containing sewage and chemicals, and loss of electricity in extreme summer heat created major public health risks.
• Services Disrupted: Emergency services, hospitals, and schools were shut down or overwhelmed for months.
Impacts on Property (Hurricane Katrina)
• Levee Failure: Storm surges and high water overwhelmed and broke the protective floodwalls and levees around New Orleans, leaving approximately 80% of the city flooded.
• Housing Destruction: More than 200,000 homes were damaged or completely destroyed by high winds and deep standing floodwaters.
• Infrastructure Damage: Major highway bridges (such as the I-10 Twin Span Bridge) were collapsed or washed away, power grids were wiped out, and municipal water supplies were ruined.
• Economic Cost: Total property damage and economic costs reached between \$100 billion and \$160+ billion, making it one of the costliest natural disasters in US history.
Key Takeaway: When describing Hurricane Katrina, always mention the failure of the levee systems, the flooding of 80% of New Orleans, and support your points with exact facts (e.g., 1,800+ deaths, Category 3 landfall, over 200,000 homes destroyed).
4. Common Exam Pitfalls to Avoid
CCEA examiners frequently report the following mistakes. Make sure you avoid them:
• Pitfall 1: Choosing a British Isles Event: Never write about UK heatwaves, storms, or floods (such as the Somerset Levels floods) for this question. The specification strictly requires an event outside the British Isles.
• Pitfall 2: Using a Tectonic Hazard: Do not write about the 2010 Haiti Earthquake or the 2011 Japan Tsunami. These are geological hazards, not weather hazards.
• Pitfall 3: Blurring People and Property: If a question asks for impacts on people, writing only about broken bridges and levee walls will cost you marks. Keep your answers clearly grouped into human/social impacts versus physical/structural impacts.
• Pitfall 4: Being Too Vague: Avoid writing vague sentences like "many people died and houses broke". Instead, write: "Over 1,800 people died, and floodwaters damaged over 200,000 homes when 80% of New Orleans was submerged due to levee failures."
5. Quick Revision Summary Checklist
Before moving on, check that you can answer these key questions:
✔ Can you name an extreme weather event outside the British Isles (e.g., Hurricane Katrina, August 2005)?
✔ Can you give two specific impacts on people with facts/figures (e.g., over 1,800 deaths, tens of thousands sheltered in the Superdome)?
✔ Can you give two specific impacts on property with facts/figures (e.g., 80% of New Orleans flooded due to levee failure, over \$100 billion to \$160+ billion in damages, 200,000 homes destroyed)?
✔ Can you clearly explain the difference between human (social) impacts and structural (property/economic) impacts?