Impacts of Climate Change (Cambridge (CIE) IGCSE Geography) : Revision Note

Impacts of climate change

Health

• Increased temperatures and lack of precipitation may lead to the spread of diseases:

  • Italy has experienced cases of malaria since 2017, when it was previously a malaria-free area

  • An additional 280 million people may be affected by malaria

  • Waterborne diseases are more likely to spread

• Heat waves may become more frequent

• Heat stroke, dehydration and sunburn increase during heat waves

• Stagnant air during heat waves increases air pollution levels:

  • Respiratory diseases increase and those suffering from respiratory illnesses such as asthma may be more affected 

• Increased temperatures negatively affect people with cardiopulmonary diseases

• Diets may be restricted by food shortages leading to malnutrition and famine

Homes and settlements

• Increased flooding due to sea level rise and increased frequency and severity of storms will lead to the displacement of large numbers of people

• Settlements in low-lying areas may have to be abandoned or need additional defences against sea level rise

  • Moving settlements or improving flood defences will be costly

Agriculture

• Farmers may need to change the crop they grow if climate conditions become unsuitable

• Coastal flooding may lead to salt intrusion

• Reduced availability of water will mean that irrigation is limited or impossible

• Food shortages will lead to malnutrition and famine

Employment

• Job opportunities may change or decrease because:

  • Tourism may decline in some areas; for example, ski resorts may close due to the lack of reliable snow

  • Coastal resorts may be at risk of flooding leading to the closure

  • Farmers may have to change the crop they grow or livestock they raise or leave farming

  • In some areas, agriculture may decline due to rising temperatures or changing rainfall patterns

Sea level rise

• Warmer temperatures cause the water in seas and oceans to expand, increasing the sea level

• Melting ice is adding to the increasing volume of water:

  • Average sea levels have risen 23 cm since 1880

  • Sea levels are forecast to increase a further 30 cm by 2050

• Low-lying coastal areas and islands are at higher risk of flooding:

  • The Maldives may be uninhabitable by 2050 

• Beach erosion will increase, leading to greater coastal erosion 

• Coastal ecosystems, including coral reefs and mangrove swamps, will be affected

• Saltwater is contaminating freshwater supplies and affecting coastal agriculture

Ecosystem change

• The location of biomes may shift to the north (Northern Hemisphere) and south (Southern Hemisphere) as they rely on specific climate conditions:

  • Polar and tundra biomes are at risk of becoming extinct as they cannot shift any further north/south

• Increasing sea temperatures and ocean acidification have resulted in coral bleaching

• Migration and behavioural patterns of animals affected by changing temperatures:

  • Fish species are moving north and south of their usual habitats to seek cooler water

  • Reduced hibernation due to warmer winters

• Melting of ice caps/glaciers leading to changing ocean currents

• Mangrove swamps and coral reefs are threatened by rising sea levels

• Loss of habitats through flooding, drought and wildfires

• Food webs breaking as species numbers are reduced and food sources are decreased

• Loss of plants and vegetation

Natural hazards

• Changes in climate patterns are likely to increase the frequency and severity of storms:

  • The 2020 Atlantic hurricane season was the first most active on record and 2021 was the third most active

• The frequency and length of droughts are increasing

• Dry conditions lead to the increased risk of wildfires:

  • In 2021, Australia, Greece, South Africa, Brazil and the USA were just some of the places to experience severe wildfires

  • In September 2021, the USA National Fire Centre reported 44,647 wildfires that had burnt 5.6 million acres

• Rising sea levels together with increased storms lead to increased flooding risk

Responses to climate change

• Global warming and climate change require an international response because they affect the entire globe

• Responses can involve either adaptation or mitigation

• In 1988 the Intergovernmental Panel on Climate Change (IPCC) was set up to assess the 'risks of human-induced climate change'

• This was followed by several international agreements

International agreements

Earth Summit, Rio 1992

• Set out aims to stabilise greenhouse gas levels 

Kyoto Protocol 1997

• Delegates from 150 countries agreed to reduce greenhouse gas emissions

• It stated that industrialised countries would reduce emissions to below the levels in 1990

• Developing countries, including China and India, were exempt from the agreement

• The USA did not sign up for the treaty

• Canada withdrew in 2011, stating that without China and the USA, the treaty would not work

Marrakech Agreement, 2007

• It was agreed that funding would be provided to less developed countries to support them in adapting to the effects of climate change

Paris Agreement 2015

• Global agreement to limit global warming to 2°C (preferably 1.5°C) above pre-industrial levels

• The agreement also includes reducing CO₂ emissions by at least 60% by 2050

• Signed by 196 countries, including the USA and China (the USA withdrew in 2020 and rejoined in 2021) 

Conference of the Parties (COP)

• The United Nations (UN) holds an annual (every year) meeting to discuss climate change.

• COP29 was held in Baku, Azerbaijan

• All nations agreed to:

  • continue to take action to further reduce greenhouse gas emissions

  • triple financial aid to developing countries

Reducing emissions 

• Emissions can be reduced in several ways, including:

  • reducing deforestation 

  • increasing afforestation

  • improving energy efficiency in industry and domestic appliances

  • reducing emissions from industry

  • improving public transport

  • electric vehicles

  • use of renewable energy and nuclear power

Effectiveness of mitigation and adaptation strategies