Introduction to 'the chemistry of climate change'

Scarcely a week goes by without at least one item somewhere in the media about climate change or global warming.  Images of polar bears with open water between ice floes, melting icebergs and storms are all used to help capture our attention.  Many people, including sixth form students, are concerned about the consequences for our planet - although few would be able to explain why it is that burning fossil fuels are causing the changes that are reported.

The chemical sciences have much to contribute to our understanding of climate change.  From explaining why it is that carbon dioxide and other gases cause the warming of our planet to analysing ancient ice cores to find out how the concentrations of these gases have changed over time and in helping to construct models to predict what might happen in the future, chemical scientists are involved in current research in many areas.

This resource aims to:

• describe some of the research which has been and is currently being undertaken
• show how the chemical sciences can contribute to our understanding of the problems and challenges of climate change
• enable students to use their chemical knowledge in this familiar, yet perhaps not particularly well-understood, context
• equip students better to understand the news and media reports which they see
• inspire students to study the chemical sciences further themselves.

There are several activities within the resource.  The first two are:

• The greenhouse effect and global warming
  This covers the greenhouse effect from a chemical perspective, looking at how molecules interact with IR radiation.  
• Climate change and carbon dioxide
  This activity looks at the evidence for the increase in temperature and carbon dioxide concentration in the atmosphere.

These two activities are the keys to understanding the rest and should be completed before the others are attempted.  The following activities expand the picture:

• Carbon dioxide is not the only greenhouse gas
  A study of some of the other gases which contribute to the greenhouse effect, including another look at how molecules interact with IR radiation.
• Climate feedbacks
  This activity aims to help students think about factors which affect the energy flow and therefore the temperature of the earth, the weather and the climate.  This links to a look at how climate modelling is undertaken.
• Paleoclimatology and ice core chemistry
  This is a fascinating activity which tells the story of how ice cores are extracted and analysed, including a discussion of the importance of knowing and understanding the errors in data.
• Earth surface temperature data
  Students use up-to-date online information and data from various weather stations around the globe to look at the evidence for climate change.

A practical activity to show the greenhouse effect are described in p167-170 Lister, T, Classic Chemistry Demonstrations, Royal Society of Chemistry, 1995.  This resource is available online on ChemistryTeachers.org (search for 'greenhouse effect' and the resource is shown as 'Greenhouse Effect - 1').