Climate Change: Key Terms (Cambridge (CIE) IGCSE Geography): Revision Note

Climate change: Key terms

Causes of climate change

Atmospheric dust – Tiny particles from asteroids or volcanic eruptions that block sunlight and cool the Earth's surface.

Carbon dioxide (CO₂) – A greenhouse gas released through activities like burning fossil fuels, which traps heat in the atmosphere.

Chlorofluorocarbons (CFCs) – Man-made chemicals once used in fridges and aerosols that trap heat and damage the ozone layer.

Enhanced greenhouse effect – The increased trapping of heat due to higher levels of greenhouse gases from human activity.

Greenhouse effect – A natural process where certain gases trap heat in the Earth's atmosphere, keeping the planet warm enough for life.

Greenhouse gases – Gases such as CO₂, methane, and nitrous oxide that trap heat in the atmosphere.

Historical sources – Old diaries, art, and records used as indirect evidence of past climate changes.

Ice cores – Cylinders of ice from glaciers that contain air bubbles, helping scientists study past climates.

Methane (CH₄) – A powerful greenhouse gas released from livestock, rice paddies, landfill sites, and decaying organic material.

Milankovitch cycles – Long-term changes in the Earth's orbit, tilt, and wobble that affect how much sunlight the Earth receives.

Natural sources of greenhouse gases – Includes water vapour (from evaporation), carbon dioxide (from wildfires), and methane (from decaying matter).

Nitrous oxide (N₂O) – A greenhouse gas released from soil, oceans, and fertilisers.

Pollen – Preserved plant material in sediments used to identify ancient climates.

Quaternary period – The last 2.6 million years during which the Earth has gone through many glacial and interglacial periods.

Sea ice position – The extent of ice coverage in the ocean, which scientists track to understand climate trends.

Short- and long-wave radiation – Sunlight reaches Earth as short waves; Earth radiates heat back as long waves, some of which are trapped by greenhouse gases.

Sunspot activity – Dark patches on the sun’s surface that can cause slight increases in solar energy received by Earth.

Tree rings – The rings in tree trunks show how trees grew each year, which indicates past climate conditions.

Volcanic eruption – A natural event that releases ash into the atmosphere, blocking sunlight and causing temporary cooling.

Water vapour – A natural greenhouse gas formed by evaporation from oceans and transpiration from plants.

Impacts of climate change

Agriculture – Farming is affected by changing temperatures, water shortages, and extreme weather, leading to food shortages.

Air pollution – Warmer temperatures can trap dirty air, worsening health conditions like asthma.

Biodiversity loss – Climate change causes species to go extinct as their habitats change or disappear.

Coral bleaching – Coral reefs lose their colour and die due to warming ocean temperatures.

Drought – Prolonged periods of little rainfall, causing crop failures and water shortages.

Ecosystem shift – Entire biomes, like tundra or rainforests, may move or vanish due to climate change.

Employment – Jobs in farming, tourism, and fishing may be lost or need to adapt to new conditions.

Flooding – Sea level rise and heavy rainfall increase the risk of flood events, especially in low-lying areas.

Food insecurity – Not having enough reliable access to affordable, nutritious food.

Health impacts – Heatwaves, poor air quality, and the spread of disease lead to more illness and death.

Heatwave – A period of excessively hot weather that can cause heatstroke and dehydration.

Malaria – A disease that can spread more easily with warmer, wetter conditions.

Migration – People forced to leave their homes due to sea level rise, floods, or food shortages.

Natural hazards – Includes stronger storms, droughts, and wildfires becoming more frequent due to climate change.

Respiratory disease – Illnesses like asthma that get worse during periods of heat and poor air quality.

Sea level rise – As oceans warm and ice melts, sea levels rise, threatening coastlines worldwide.

Tourism decline – Destinations such as ski resorts or beaches may become less attractive or disappear entirely.

Waterborne diseases – Illnesses like cholera that spread when drinking water is contaminated, especially after floods.

Climate Change Case Study: Bangladesh

Adaptation strategies – Ways Bangladesh is adjusting to climate impacts, like building flood shelters and planting mangroves.

Bangladesh climate change strategy and action plan (2009) – A national policy for adapting to and reducing climate change impacts.

Bay of Bengal – The sea east of Bangladesh where sea level rise and tropical storms cause severe flooding.

Coastal embankments – Man-made barriers that protect Bangladesh’s coastal areas from storm surges and rising seas.

Dhaka – The capital of Bangladesh, which faces high flood risks due to urbanisation and rising water levels.

Early warning systems – Community-based alarms and alerts to warn people before cyclones and floods strike.

Electric vehicles target – Bangladesh aims to have 15% of its vehicles electric by 2030.

Floodplain – Low-lying land next to rivers that floods regularly; more than 80% of Bangladesh is floodplain.

Mangrove planting – Trees grown along coasts to reduce erosion and provide natural protection from storms.

Monsoon – The seasonal rains in Bangladesh are becoming more intense due to climate change.

Renewable energy policy (2008) – A plan to increase clean energy use in Bangladesh, especially solar power.

Salinity intrusion – Saltwater seeping into freshwater systems due to sea level rise, making farming harder.

Sea level rise in Bangladesh – A 1-metre rise would submerge 20% of the land and displace 15 million people.

Shelters on stilts – Raised buildings where people and animals can stay safe during floods.

Submersible roads – Roads that can cope with being underwater during floods without being damaged.

Sundarbans – A large mangrove forest in Bangladesh under threat from rising seas and biodiversity loss.