Impacts of Climate Change (Cambridge (CIE) AS Environmental Management)

Revision Note

Alistair Marjot

Written by: Alistair Marjot

Reviewed by: Bridgette Barrett

Environmental Impacts of Climate Change

Diagram showing how climate change affects the environment
How climate change affects the environment

Impacts of Climate Change on the Environment

Change

Impacts

Examples

Temperature and precipitation

Alteration of ecosystems and habitats due to shifting temperature regimes

Coral bleaching events leading to widespread loss of coral reefs

Changes in precipitation patterns leading to droughts or increased flooding

Increased frequency and intensity of wildfires in forested regions due to severe droughts combined with heatwaves

Disruption of agricultural cycles affecting crop yields and food security

Decline in crop productivity due to heat stress and water shortages

Sea level

Coastal erosion and loss of land due to rising sea levels

Submergence of low-lying island nations such as Tuvalu and the Maldives

Increased risk of flooding in low-lying coastal areas and estuaries

Inundation of coastal cities like Miami and New York during storm surges

Ocean and wind circulation

Disruption of ocean currents affecting marine ecosystems and weather patterns

Slowing of the Gulf Stream leading to altered weather patterns in Europe

Changes in wind patterns impacting agriculture, transportation and weather

Shifts in monsoon patterns affecting agricultural productivity in Asia

Melting of sea ice, ice sheets, glaciers

and permafrost

Accelerated melting contributing to sea level rise and coastal inundation

Melting of Greenland's ice sheet

Release of stored greenhouse gases (e.g. methane) from thawing permafrost

Thawing permafrost in the Arctic releasing methane, accelerating global warming

Loss of habitat for polar species dependent on ice-covered environments

Decline in polar-bear populations due to loss of sea ice hunting grounds

Species distribution and biodiversity

Range shifts and habitat loss for plants and animals due to changing climates

Poleward migration of species such as butterflies and birds

Increased extinction risk for species unable to adapt or migrate

Decline in populations of coral-dependent fish species due to bleaching events

Disruption of ecological interactions and food webs affecting biodiversity

Disruption of pollinator populations, such as bees and butterflies, affecting plant reproduction and ecosystem stability

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 ingress is contaminating freshwater supplies and affecting coastal agriculture

Map showing the effects of a 1 m sea level rise in the UK and other parts of Europe
Effects of a 1 m sea level rise in the UK and other parts of Europe

Polar Habitat Change

  • Many species rely on the ice that forms at the poles for their habitat:

    • Sea ice forms when the ocean freezes

    • Sea ice that is attached to land is known as landfast ice

  • Global warming means that there is less sea ice, and the ice that does form breaks apart and detaches from the land earlier in the year than previously, causing problems for breeding animals:

    • Emperor penguins, Aptenodytes forsteri

      • These birds breed on Antarctic sea ice, laying and incubating their eggs and raising their young

      • The early melting of sea ice is not giving them enough time to raise their young

    • Walruses, Odobenus rosmerus

      • These mammals rely on Arctic sea ice, where mothers can alternate periods of feeding their young and hunting for food in the ocean nearby

      • The early loss of ice means that nursing mothers need to care for their young further from the water's edge, leaving young without protection for longer periods when the mothers hunt for food

Photo of Emperor penguin adult with chicks
Emperor penguins rely on sea ice to breed successfully (CC BY-SA 4, via Wikimedia Commons)

Range Shifts of Temperate Species

  • Species exist within tolerance limits, meaning that they can only survive in habitats where the environmental conditions fall within their range of tolerance:

    • E.g. a marine species may only be able to survive in seawater that falls within certain temperature limits

  • Climate change is causing changes to many local environmental factors; when this causes the conditions of a habitat to change beyond what a species can tolerate, the species must either migrate to a new habitat or face extinction

  • This migration may involve a shift in range distribution towards the poles, or to a higher altitude, to an area where temperatures are cooler:

    • A range shift towards the poles is described as a poleward shift

    • A range shift to a higher altitude is an upslope shift

Upslope Range Shifts in Montane Bird Species

  • Montane, i.e. mountain-dwelling, species will live at an altitude that suits their needs:

    • Altitude affects temperature and oxygen availability, so will influence plant growth and rates of aerobic respiration

  • Evidence gathered in the mountains of Papua New Guinea over a 50 year period shows that many bird species have migrated to higher altitudes over this time period:

    • This is not the case for all species; a few have stayed in the same place or moved downslope

  • E.g. data gathered from Mt Karimui show that bird species have moved upslope in this region by an average of more than 100 m

Graph demonstrating upslope range shifts in birds
Changes in upper elevation limits of species on Mt Karimui between 1965 and 2014 show that most species have increased their upper elevation limit

Examiner Tips and Tricks

Note that you will not be expected to know the Latin names of species in an exam, but it is useful to know some examples of species that are being negatively impacted by climate change

Human Impacts of Climate Change

Impacts of Climate Change on Human Populations

Impact

Description

Examples

Increased frequency and severity of extreme weather events

More frequent and intense hurricanes, cyclones and typhoons leading to widespread flooding and destruction of infrastructure

Hurricane Katrina (2005) devastated New Orleans, causing extensive flooding and displacement of residents

Severe droughts resulting in water shortages, crop failures and wildfires, particularly in arid and semi-arid regions

The California drought (2011-2017) led to water rationing, crop losses and increased wildfire activity across the state

Damage to property and loss of life during extreme weather events

Destruction of homes, buildings and critical infrastructure during storms, floods and heatwaves, resulting in economic losses

Superstorm Sandy (2012) caused widespread damage along the U.S. East Coast, resulting in billions of dollars in property damage

Loss of life due to heat-related illnesses, drowning and injuries caused by extreme weather events

Heatwaves in Europe (2003) resulted in thousands of deaths, particularly among vulnerable populations such as the elderly

Forced migration

Displacement of communities due to rising sea levels, flooding, drought and conflicts over dwindling resources

Climate refugees from Bangladesh are relocating to urban areas due to coastal erosion and flooding caused by sea level rise

Migration from rural to urban areas as agricultural livelihoods become unsustainable due to changes in climate and water availability

Farmers in regions of Sub-Saharan Africa are migrating to cities in search of alternative livelihoods due to drought and crop failures

Impacts on crop yields and increased pest outbreaks

Decreased crop productivity and yield losses due to changes in temperature, precipitation patterns and water availability

Decline in wheat yields in Australia due to heat stress and reduced rainfall

Expansion of pest populations and diseases affecting crops, leading to reduced agricultural output and food security

Outbreak of coffee leaf rust in Central America resulting in significant losses for coffee farmers

Impacts on food, energy and water security

Disruption of food production and distribution systems, leading to food shortages, price volatility and insecurity

Food shortages and price spikes following extreme weather events, such as hurricanes or droughts

Reduced availability and quality of freshwater resources due to changes in precipitation patterns and increased evaporation

Water rationing in Cape Town, South Africa, during a prolonged drought leading to severe water shortages (2017-2018)

Increased demand for energy resources for cooling during heatwaves and for water pumping during droughts, straining energy systems

Power outages in California during heatwaves due to high demand for air conditioning

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Alistair Marjot

Author: Alistair Marjot

Expertise: Biology & Environmental Systems and Societies

Alistair graduated from Oxford University with a degree in Biological Sciences. He has taught GCSE/IGCSE Biology, as well as Biology and Environmental Systems & Societies for the International Baccalaureate Diploma Programme. While teaching in Oxford, Alistair completed his MA Education as Head of Department for Environmental Systems & Societies. Alistair has continued to pursue his interests in ecology and environmental science, recently gaining an MSc in Wildlife Biology & Conservation with Edinburgh Napier University.

Bridgette Barrett

Author: Bridgette Barrett

Expertise: Geography Lead

After graduating with a degree in Geography, Bridgette completed a PGCE over 25 years ago. She later gained an MA Learning, Technology and Education from the University of Nottingham focussing on online learning. At a time when the study of geography has never been more important, Bridgette is passionate about creating content which supports students in achieving their potential in geography and builds their confidence.