Begin with a class discussion on climate and global warming. What information does the class already have? How reliable do they think that information is?
You might wish to show your class the Australian Climate Commission Report from 2012 called The Angry Summer (3.6 MB PDF). Page 3 of this report summarises extreme weather events of 2012 in a striking poster format.
How has the average global temperature changed since 1950?
The data for average global temperature from 1950 to 2012 is supplied and already graphed. A quick demonstration of the Climate and temperatures spreadsheet and how to use it should lead into students working either on their own or in pairs.
What is the average rate of change of the mean global temperature?
The program has calculated a line that best fits the variable data. It shows a steady temperature rise over the years.
By setting the starting value for the 1950s, students can work out the equation (or formula) for the line of best fit, and hence the rate at which the temperature is changing.
What is likely to be the global temperature in the future if this historical rate does not change?
Students can use this rate of change to make predictions about the average global temperature in future years, if this steady rate of change continues.
How can a few degrees increase in temperatures increase 'extreme weather events'?
Students should read the explanation about the Effects of global warming (spreadsheet) on the first tab before going to the 'explore' tab. Some may need a more guided explanation to make sure they know what to do. You might prefer to demonstrate using a projector.
The spread of temperatures in any locality is normally distributed. This distribution can be graphed for the 'present' climate using the mean and standard deviation. The program can determine the percentage of days that are over any given temperature using a formula for the area under the curve.
Moving any curve to the right (to show a rising global mean) enables students to compare the number of days greater than a given temperature, and find the ratio of hot days in the future compared to now. It is also possible to explore the effect of changing the spread of the temperature distribution. The point of this comparison is that ‘extreme weather events’, often generated by higher temperatures, will become much more common, if the model is correct.
You might like to ask the class to share their findings.
You can download the Climate and global warming: Teacher notes. <make a pdf of page for download>
Australian Curriculum links
Year 6
Interpret secondary data presented in digital media and elsewhere (ACMSP148)
Year 7
Identify and investigate issues involving continuous or large count data collected from primary and secondary sources (ACMSP169)
Year 8
Plot linear relationships on the Cartesian plane with and without the use of digital technologies (ACMNA193)
Investigate the effects of individual data values on the mean and median (ACMSP207)
Year 10A
Calculate and interpret the mean and standard deviation of data and use these to compare data sets about a population based on a sample (ACMSP278)
Use information technologies to investigate bivariate numerical data sets. Where appropriate use a straight line to describe the relationship allowing for variation (ACMSP279)
