Extreme Weather Events in the UK
The AQA GCSE specification requires you to study a recent example of an extreme weather event in the UK. This lesson examines Storm Desmond (December 2015) as a detailed case study, along with other significant events to provide context. Understanding the causes, impacts, and responses to extreme weather is crucial for exam success.
What Is an Extreme Weather Event?
An extreme weather event is a weather event that is significantly different from the average or usual weather pattern. These events are rare, severe, and can cause substantial damage.
Examples of extreme weather in the UK:
- Record-breaking rainfall and flooding
- Severe heatwaves
- Heavy snowfall and prolonged cold
- Powerful storms with destructive winds
- Prolonged drought
Case Study: Storm Desmond (December 2015)
Background
| Detail | Information |
|---|
| Date | 5–6 December 2015 |
| Location | Northern England (Cumbria, Lancashire) and southern Scotland |
| Type | Extra-tropical cyclone (deep low-pressure system) |
| Rainfall record | 341.4 mm in 24 hours at Honister Pass, Cumbria — a UK record |
| Named by | Met Office (part of the storm naming system introduced in 2015) |
Causes
- A strong jet stream funnelled a series of deep low-pressure systems across the Atlantic towards the UK.
- Atmospheric rivers — narrow corridors of moisture-laden air from the tropics — directed vast quantities of water vapour towards the UK.
- Previous weeks of heavy rainfall had already saturated the ground, meaning any further rain would immediately run off into rivers.
- Steep terrain in the Lake District and Pennines channelled rainfall rapidly into river valleys.
- Some scientists linked the unusually intense jet stream to climate change and warmer-than-average Atlantic sea temperatures.
Exam Tip: When explaining the causes of an extreme weather event, link to global atmospheric circulation concepts (jet stream, air masses, low pressure). This demonstrates your ability to make connections across the specification.
Effects of Storm Desmond
Social Effects (impacts on people)
- Homes flooded — over 5,200 homes flooded in Cumbria alone, with thousands more across Lancashire and Scotland.
- Evacuations — thousands of people evacuated from their homes, some for months.
- Three people died during the flooding.
- Loss of essential services — 61,000 homes lost electricity when the Electricity North West substation at Lancaster was flooded. Some areas were without power for four days.
- Mental health impacts — residents reported anxiety, depression, and PTSD in the months and years following the floods.
- Disruption to daily life — schools closed, workplaces inaccessible, community events cancelled.
Economic Effects (impacts on business and money)
- Estimated cost: $500 million (£400 million+) in damage and economic losses.
- Businesses flooded and forced to close — some for weeks or months. Many small businesses never reopened.
- Transport infrastructure destroyed — roads, bridges, and railway lines damaged or washed away.
- The Pooley Bridge in Cumbria (a Grade II listed 18th-century bridge) was completely destroyed by floodwaters.
- Agricultural losses — farmland flooded, livestock lost, fences and field boundaries destroyed.
- Insurance claims — tens of thousands of claims made, leading to increased premiums in flood-prone areas.
Environmental Effects
- River channel changes — rivers carved new channels and deposited large amounts of sediment across floodplains.
- Soil erosion — topsoil washed from agricultural fields.
- Pollution — floodwaters carried sewage, agricultural chemicals, and oil into rivers and lakes.
- Habitat disruption — wildlife habitats along river corridors were damaged.
Responses to Storm Desmond
Immediate Responses
- The Environment Agency issued severe flood warnings ("danger to life") for rivers across Cumbria and Lancashire.
- Mountain rescue teams, fire and rescue services, and the military (600 soldiers deployed) assisted with evacuations and rescue operations.
- The RNLI deployed lifeboats in flooded streets in Carlisle and Cockermouth.
- Emergency shelters were set up in schools, community centres, and leisure centres.
- The government activated the COBRA emergency committee to coordinate the national response.
- Volunteers and community groups played a crucial role — local people rescued neighbours, provided food, and opened their homes to the displaced.
Long-term Responses
- The government announced a $150 million (£100 million+) flood defence improvement programme for Cumbria.
- New flood defences were built in Carlisle, Cockermouth, and Kendal, including higher flood walls and improved drainage.
- Pooley Bridge was rebuilt as a modern bridge designed to withstand future floods (completed 2020).
- The Environment Agency reviewed its flood risk maps and updated flood warning systems.
- Natural flood management schemes were implemented upstream:
- Tree planting in upland areas to slow water runoff.
- Leaky dams (natural barriers) in streams to slow water flow.
- Peat bog restoration to increase water absorption.
- Flood Re insurance scheme (launched 2016) made affordable flood insurance available to homeowners in high-risk areas.
- Debate intensified about whether climate change was making such events more likely, and whether current flood defences are adequate.
Exam Tip: For full marks on a case study question, you need specific place names, dates, and statistics. Learn at least 3–4 key facts for each category (social, economic, environmental effects).
Other Significant UK Extreme Weather Events
Beast from the East (February–March 2018)
| Detail | Information |
|---|
| Cause | Polar continental air mass from Siberia brought bitterly cold air westward |
| Temperatures | As low as -12 °C in parts of England and Scotland |
| Snowfall | Up to 50 cm in parts of Scotland, eastern England, and south Wales |
| Impacts | Schools closed, flights cancelled, motorways gridlocked, rural communities cut off, several deaths from hypothermia |
| Named | Met Office issued red weather warnings (rare "danger to life" level) |
UK Heatwave (July 2022)
| Detail | Information |
|---|
| Record temperature | 40.3 °C at Coningsby, Lincolnshire — first time UK exceeded 40 °C |
| Cause | Tropical continental air from North Africa combined with a strong high-pressure system |
| Impacts | Wildfires across London and eastern England, rail services suspended (tracks buckled), record demand for ambulances, increased mortality among elderly |
| Significance | Widely attributed to climate change — scientists estimated such temperatures would have been "virtually impossible" without human-caused warming |
Winter Floods 2013–2014
- The wettest winter on record for many parts of England.
- The Somerset Levels were flooded for months — entire villages were cut off.
- The Thames flooded, affecting communities in Surrey and Berkshire.
- Estimated cost: over $500 million (£400 million+).
- Led to a major review of UK flood management policy.
Is Extreme Weather Becoming More Common?
Evidence suggests that extreme weather events in the UK are becoming more frequent and more intense: