University of Bristol
Wellcome Trust
Recommended by:
Society of Biology
PEEP for Physics & Ethics at GCSE


Global warming

  • Global warming is due to an enhanced ‘greenhouse effect
  • This enhanced effect is caused by an increase in ‘greenhouse’ gases in the atmosphere.
  • Predicting the exact effects of an increase in global temperature is very difficult.
  • There are many possible biological and ecological consequences of increasing temperature or Global Warming.
  • It is expected that greater warming will occur at the poles more than the equator and this will effect atmospheric circulation patterns which are dependent on the temperature differences between these two areas.
  • Regional rainfall patterns may also be drastically altered, which will change the patterns of world food production.
  • Sea levels will rise due to -
    • Melting of ice (glaciers and polar ice)
    • The thermal expansion of water
  • This rise will cause –
    • Flooding
    • Salinisation of soils
    • Coastal erosion
  • No one is certain how quickly it will rise but for the UK, an estimate of 0.3m to 0.6m by the year 2050.

The following table summarise these and other possible effects, some are even beneficial.

Key:-    Change in: change    increase increase    Leads to: leading to    Decrease in: decrease

Increasing temperature

increase sea level (melting of ice and thermal expansion of water)

Leads to: 

increase coastal erosion

Leads to:

increase habitat loss e.g. marshes, dunes, mangroves and coral reefs.

Leads to:

increase salinisation (more salty) of estuaries, coastal rivers and soils

increase temperature freshwaters

Leads to:

Change in: species distribution including local extinction

Change in: pattern of succession due to temperatureincrease and this will favour some species more than others.

Change in: rainfall pattern e.g.increaseintensity and frequency (climate change)increasestorms

Leads to:

Change in: distribution of grasslands and savannahs and drying out of wetlands

Northern migration of boreal (evergreen/coniferous) forest

increaseForest productivity

temp was a limiting factor to growth

Decrease in: Forest productivity

Leads to:

Desiccation (drying out), causing wilting, defoliation and — fires.

increaseAgricultural production

Leads to:

increaseyields from crops although the overall quality may be lower.

increasewater or temperature stress to animals

Leads to:

Decrease in: resistance to opportunistic pests/disease e.g. coral reef organisms

increasein pests and disease

Leads to:

Pests and disease will move to new geographical areas e.g. spread of malaria

increaseglacial melting at poles

Leads to:

DramaticChange in: in food webs

Leads to:

Decrease in: productivity and biodiversity e.g. penguin populations



These are dealt with in detail in the Climate Change section.


  1. The BBC have created a  Series of pictures to show how global warming may have changed the environment.
    Do you think they are all a direct result of global warming?
  2. There is a  website devoted to the Effects of Global Warming.
    The author clearly has the view that Global Warming is a very serious problem.
    1. Find out on what they base their evidence and who exactly is the author?
    2. Do you think it is an accurate account or is it over-exaggerated?
  3. Evidence against global warming – is it a myth?
     This following Australian website gives a comprehensive list of resources. Those discussing evidence against Global Warming can be found near the middle of the long scrolling page.
    Draw up a table for evidence ‘for’ and ‘against’. Is it a myth?


 Pollution through human activities.


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NOT RATED amy 21-04-08 14:46
this site is kind of boring