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2 Climate Change - Coggle Diagram
2 Climate Change
2.1 Evidence of climate change
2.1.1 Evidence for Climate Change
Past Patterns of Climate Change
Last Ice Age ended ~25,000 years ago
Quaternary Period (last 2.6 million years): glacial & interglacial periods
Climate changes through warm & cold periods
Sea ice positions
Less Arctic sea ice due to warming
Shows recent climate change
Ice cores
Trap air bubbles & ash
CO₂ levels reveal past climates
Record up to 2.6 million years
Global temperature data
Shows long-term rise in global temperatures
Preserved pollen
Identifies past vegetation
Indicates past climate conditions
Tree rings
Wider rings = warmer, wetter years
Fossils reveal past climates
Art and diaries
Historical records of climate
e.g. River Thames Frost Fairs
2.1.2 Causes of climate change
Natural greenhouse effect
Short-wave in, long-wave trapped
Greenhouse gases keep Earth ~15°C (not -18°C)
Examples of Natural greenhouse gases
H₂O: evaporation
CO₂: volcanoes, respiration
CH₄: decomposition
N₂O: soils & oceans
Causes of Natural Climate Change
Milankovitch Cycles
Changes in orbit, tilt & wobble
Alter incoming solar radiation
Volcanic eruptions
Ash blocks sunlight → cooling
Sunspots
More sunspots → slightly warmer
Atmospheric dust
Dust blocks sunlight → cooling
Human Sources of Greenhouse Gases
CO₂
Fossil fuels
Deforestation
CH₄
Cattle
Rice farming
Landfill
N₂O
Fertilisisers
Fossil fuels
Chlorofluorocarbons
Aerosols
Refrigeration
Main human activities
Fossil fuels → CO₂
Agriculture → CH₄, N₂O, deforestation
Construction → cement (CO₂)
Transport → fossil fuels (CO₂)
2.1.3 Climate change as a global Issues
Impacts of Sea Level Rise
Social
Displacement
Food & water shortages
Malnutrition
Environmental
Coastal erosion
Coral reefs & mangroves lost
Changing ecosystems & migration
Economic
Flood defences & relocation costly
Loss of jobs & tourism
Sea level rising due to thermal expansion, melting glaciers & ice sheets, this threatens 410 million people by 2100
Maldives
80% of islands <1 m above sea level
Risk of becoming uninhabitable by 2050
Responses: artificial island (Hulhumalé) & sea defences
Extreme Weather Events
Warmer oceans → stronger storms
More heatwaves & droughts
Climate change increasing weather-related migration
Climate Change Impacts
Social
Displacement
Disease
Food & water shortages
Environmental
Coral bleaching
Wildfires
Biodiversity loss
Species migration
Economic
Damage to infrastructure
Crop losses
Reduced tourism
Weather Patterns in the UK
Warmer, wetter winters & drier summers
More 40°C+ days
More extreme weather
UK Climate Change Impacts
Social
More heat-related deaths
Fewer cold-related deaths
More hosepipe bans
Environmental
Wildfires
Ecosystem & species changes
Economic
Longer growing season
New crops possible
Less water for farming & power stations