Extreme Weather in the UK and Climate Change
UK Weather Hazards
The UK experiences a range of weather hazards including heavy rainfall and flooding, storms and strong winds, heatwaves, drought, cold spells and snow, and thunderstorms. The UK's weather is influenced by its position between the cold polar air mass to the north and warm tropical air mass to the south, and by the jet stream — a band of fast-moving air at high altitude.
The UK's Weather is Becoming More Extreme
Evidence suggests that weather events in the UK are becoming more frequent and intense due to climate change:
- Warmer temperatures — the 10 warmest years on record in the UK have all occurred since 2002
- Heavier rainfall — winter rainfall has increased by approximately 12% since the 1960s
- More frequent flooding — major flood events have occurred in 2007, 2009, 2012, 2013/14, 2015/16, 2019/20, and 2023/24
Case Study: UK Flooding — Winter Storms 2015/16
Location: Cumbria, Lancashire, and Yorkshire (northern England)
Cause: Storm Desmond (December 2015) brought record-breaking rainfall — 341 mm in 24 hours recorded at Honister Pass, Cumbria (a new UK record)
Effects
- 16,000 homes flooded across northern England
- Cockermouth, Keswick, Carlisle, Lancaster, York, and Leeds all experienced significant flooding
- Lancaster lost all electrical power for 3 days when the electricity substation flooded — 61,000 homes affected
- Bridges destroyed, including a historic bridge in Pooley Bridge, Cumbria
- Estimated cost: $1.6 billion
- Schools and businesses closed; transport networks disrupted
Responses
- Emergency services evacuated residents by boat; military deployed
- Environment Agency issued severe flood warnings
- £2.3 billion invested in flood defences over the following 6 years
- York received £45 million for improved flood barriers
- Natural flood management — tree planting, restoring peatlands, creating upstream storage areas
- Debate over whether to allow floodplain development
Climate Change
Evidence for Climate Change
- Global temperature records — average global temperature has risen by approximately 1.1°C since pre-industrial times
- Ice core data — trapped air bubbles show CO₂ levels and temperature over 800,000 years
- Retreating glaciers — Arctic sea ice has declined by ~13% per decade since 1979
- Rising sea levels — global mean sea level has risen approximately 20 cm since 1900
- Changing wildlife patterns — species migrating poleward; earlier spring events (flowering, bird nesting)
Natural Causes of Climate Change
- Orbital changes (Milankovitch cycles) — variations in Earth's orbit, tilt, and wobble over tens of thousands of years
- Solar output — the Sun's energy output varies in ~11-year cycles
- Volcanic eruptions — large eruptions inject ash and SO₂ into the stratosphere, reflecting sunlight and causing temporary cooling (e.g. Mount Pinatubo 1991 cooled Earth by ~0.5°C for 2 years)
Human Causes of Climate Change (Enhanced Greenhouse Effect)
- Burning fossil fuels (coal, oil, gas) — releases CO₂; accounts for ~75% of human greenhouse gas emissions
- Deforestation — removes trees that absorb CO₂; burning releases stored carbon
- Agriculture — livestock produce methane (CH₄); rice paddies release methane; fertilisers release nitrous oxide (N₂O)
- Industry and cement production — chemical processes release CO₂
Effects of Climate Change
| Area | Effects |
|---|---|
| Environment | Melting ice caps and glaciers; rising sea levels; coral bleaching; more extreme weather events; shifting biomes; ocean acidification |
| People | Increased flood risk for coastal communities; water shortages in some regions; heat-related deaths; climate refugees; spread of tropical diseases (e.g. malaria) to new areas |
| Economy | Damage to infrastructure from flooding/storms; changing agricultural yields; increased insurance costs; new shipping routes in Arctic |
Managing Climate Change
Mitigation (reducing causes):
- Renewable energy (solar, wind, tidal, geothermal)
- Carbon capture and storage (CCS)
- International agreements (Paris Agreement 2015 — limit warming to 1.5°C)
- Carbon taxes and emissions trading schemes
- Planting trees (afforestation)
Adaptation (adjusting to effects):
- Flood defences (Thames Barrier, Netherlands sea walls)
- Drought-resistant crop varieties
- Water conservation and desalination
- Changing building designs for heat
- Managed retreat from vulnerable coastal areas