Climate Change as a Global Issue (OCR GCSE Geography)

• Global sea level rise is one impact of climate change
• The sea level has risen between 20-23 cm since 1880
• Each year the sea rises another 3.2mm
• It is estimated that 410 million people will be at risk from sea level rise by 2100

Why is climate change making sea levels rise?

• There are three reasons that climate change is leading to sea level rise:
  • Thermal expansion - water expands when warm increasing the volume of water in the seas and oceans
  • Melting glaciers - glaciers melt adding water to the seas and oceans
  • Melting ice sheets - ice in the Arctic and Antarctic is melting adding water to the seas and oceans

Impacts of sea level rise?

• There are social, environmental, and economic impacts of sea level rise

Social	Environmental	Economic
Displacement of people from their homes and communities Food and water supplies threatened by salt intrusion Food shortages lead to malnutrition and famine	Destruction of ecosystems including coral reefs and mangroves Ocean acidification Increased coastal erosion Changing patterns of animal migration and behaviour	The cost of building flood defences Relocation of people and building of new homes is expensive Loss of jobs Reduction in tourism due to the impact on coastal resorts

• Some areas, such as the Maldives are more at risk
  • Over 80% of its islands are less than 1m above sea level
  • It has been forecast that if sea levels continue to rise the islands will be uninhabitable by 2050
  • The Maldives government has taken actions including:
    • The construction of an artificial island, Hulhumalé, northeast of the capital, Malé
    • Flood walls and defences constructed around islands

• Climate change can lead to extreme weather and erratic weather patterns
• Warmer sea/ocean temperatures increase the amount of evaporation leading to more frequent and severe storms
• Droughts and heatwaves are becoming more common due to increasing average global temperatures
• The Intergovernmental Panel on Climate Change (IPCC) predicts that a 1.5° increase in average global temperature will make:
  • One in 50 - year heatwaves 8.5x more likely
  • One in 10 - year droughts 2x more likely
  • One in 10 - year storms 1.5x more likely

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• Extreme weather events including flooding and drought are forcing people to move
• The UN states that an annual average of 21.5 million people were displaced by weather-related events between 2008-2016
• Estimates suggest this could rise to a total of 1.2 billion people displaced by 2050

Social, Environmental and Economic Impacts of Sea Level Rise

Social	Environmental	Economic
Displacement of people from their homes and communities Food and water supplies threatened by flooding and drought Crop yields in sub-Saharan Africa are estimated to reduce by over 20% Food shortages lead to malnutrition and famine Lack of freshwater due to reduced precipitation Spread of disease due to higher temperatures and flooding	Destruction of ecosystems  Coral reef bleaching Wildfires destroying forests Increased water temperatures in oceans and seas Changing patterns of animal migration, hibernation, and behaviour Increased wildfires due to drier conditions Reduced biodiversity due to loss of plant and animal species	Relocation of people and building of new homes is expensive Loss of jobs Repair of buildings and infrastructure expensive Loss of crops reduces farmer's income and exports Decline in tourism in some areas: Ski resorts due to lack of snowfall Extreme temperatures such as in Europe in 2023 deter people from warmer areas

• Climate change is impacting on UK weather patterns and events
• All the ten warmest years on record in the UK have occurred in the last 20 years
• Six of the ten wettest years on record have occurred in the last 25 years
• It is predicted that by 2050 the UK will have:
  • Higher average temperatures. In the south-east, this may be between 2-2.5° higher
    • Days reaching over 40° are predicted to be 10 times more likely
  • Wetter winters, particularly in the east of the country, over 20% wetter in some areas
  • Drier summers, with much of the UK experiencing a 20-30% decrease in precipitation
• There are a range of impacts resulting from the changes in climate as outlined in the table below

Social, Environmental and Economic Impacts of Changing Weather Patterns

Social	Environmental	Economic
Increased deaths due to extreme heat In 2022 the extremes in temperature in Europe led to 61,000 excess deaths People with respiratory and heart conditions will be particularly affected There will be fewer deaths from cold Hosepipe bans may increase due to water shortages	Ecosystems may be affected by drought, flooding, and wildfires Increase in wildfires due to drier conditions in summer Changes in species in the UK and the water around the UK due to higher temperatures	Tourism may increase due to warmer, drier climate in summer Growing seasons will be longer; this may increase income for farmers and exports New types of crops can be introduced - citrus fruits, olives Less water available for irrigation and power stations