StudyDeck

Impacts of climate change

Exam code: 2217
Written by: Ashika|Reviewed by: Caroline Carroll|Updated 2 July 2026

Specification link

This page covers section 5.2.1, 5.3.1 and 5.3.2 of the CIE O Level specification.

  • 5.2.1 - The present day and predicted future impacts of climate change. For example, rising sea levels, and changes to global temperature, weather patterns, and food production.

  • 5.3.1 - The strategies (including national and international agreements) and techniques used to manage the impacts of climate change.

  • 5.3.2 - An evaluation of mitigation (including international agreements) and adaptation strategies and techniques used to manage the impacts of climate change.

Impacts of climate change

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

  • Food prices may rise

Employment

  • Job opportunities may change or decrease for the following reasons:

    • 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

Map of Bangladesh and India showing areas submerged by 1m to 5m sea level rise, affecting 15-18 million people. Major cities and Bay of Bengal labelled.
Bangladesh sea level rise predictions
  • Low-lying coastal areas such as southern Bangladesh 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

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

    • Mitigation includes ways that people try to reduce or eliminate greenhouse emissions

    • The aim is to halt global warming and therefore climate change

    • Mitigations can include international agreements as well as national and individual actions

International agreements

  • 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

Earth Summit, Rio 1992

  • In May 1992 the United Nations Framework Convention on Climate Change (UNFCCC) was established

  • It was then signed by 166 countries at the Earth Summit in Rio or at the UN headquarters

  • The Earth Summit also set out:

    • Twenty seven principles aimed at guiding countries towards more environmentally sustainable development

    • Aims to stabilise greenhouse gas levels 

    • Principles for the management, conservation and sustainable development of all forests

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

  • The Kyoto Protocol was the first legally binding international treaty to set emissions targets

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) 

  • Introduced Nationally Determined Contributions (NDCs)

    • These are climate action plans submitted by each country outlining their commitments

    • Currently these are not sufficient to meet the 2oC target (projections show 2.6-2.7oC warming by 2100)

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

    • Carbon capture and storage

    • Reducing meat consumption

    • Alternative feed for cattle to reduce methane emissions

Adaptations

  • Climate change is already impacting many countries

  • Mitigation strategies will take time to have an impact

  • Adaptations are needed to help populations cope with the impacts which are already being felt

  • Examples of adaptations include:

    • Improved building design to withstand flooding and increased storm intensity

    • More efficient use of freshwater resources and desalination

    • Coastal and river defences to reduce the impact of flooding

    • Changing the types of crop grown

    • Relocation of vulnerable communities

    • Extreme weather plans

Effectiveness of mitigation and adaption strategies

Effectiveness of mitigation and adaptation strategies

  • Climate change is a global issue

  • It requires international cooperation and collaboration

  • The effectiveness of both strategies depends on various factors, including:

    • Political willingness to implement the strategies

    • Availability of finance and economic resources

    • Technological advancements

Mitigation strategies

  • Mitigation strategies are important in the long term to reduce the rate or even halt global warming

  • Their effects can be gradual and may take time to have an impact

Challenges of mitigation strategies

  • Implementing mitigation strategies changes can be expensive

  • They rely on international cooperation and may be politically challenging to implement

    • Even if countries sign up to agreements, they may not be able to achieve the changes outlined

  • There may be resistance from industries reliant on fossil fuels

  • Not all mitigation strategies are equally effective

Adaptation strategies

  • Adaptation strategies can help reduce the short-term negative impacts of climate change

Challenges of adaptation strategies

  • Adaptation measures can be expensive and require significant infrastructure changes

  • Some adaptation strategies may not be effective when there are extreme climate events

  • Adaptation efforts may be more effective if combined with mitigation efforts