Freak weather, or not?I can’t believe this freak weather! We’ve had so much snow, and spring is really late this year…

I don’t know, I can remember having lots of snow in the sixties, and didn’t the River Thames once freeze over?

Freak weather, or not?

Mind you, the summers seem hotter, and we’re always having hosepipe bans and drought warnings…

… but I remember the summer of 1976 and that was a real scorcher! I remember queuing at the standpipe for water…

Freak weather, or not?• Many people believe that our climate is changing

and that it is due to global warming.• There are three separate questions:

– Is the climate changing?– If so, is it due to ‘global warming’?– …and if it is, what’s causing the ‘global

warming’?• We’re going to explore the first of these

questions.

Freak weather, or not?Is the climate in Britain changing?• What data would you need to have to be able to

give an informed response?• How much of a change would there need to be

to convince you that there has or has not been a change in the weather in recent years?

Freak weather, or not?The following maps from the Met Office show the average annual temperature for:• 1961 to 1990• 1971 to 2000• 1981 to 2010

What can you tell from these maps?

Freak weather, or not?What can you tell from these maps?

What can’t you tell?• Some people think that summers are getting

hotter and winters are getting colder, others that both summers and winters are getting warmer – can you determine this from these maps?

Why do the Met Office show the average temperature for 30 years rather than year by year?

Freak weather, or not?Mean annual maximum temperature since 1900

Is it getting warmer?

1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 201011

11.5

12

12.5

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13.5

14

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15

Year

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Freak weather, or not?Choose one of these questions to work on:• Are summers getting warmer?• Are winters getting warmer or colder?• Does it rain more or less than it used to? • Is the weather in Southern England changing

more quickly than the weather in Northern England?

…or pose your own question.

Freak weather, or not?Exploring the question• Decide what data you need and how you will

process and represent it.• Think about what statistical methods or

representations are most appropriate.

Teacher notes: Freak Weather, or Not?In this activity students consider common claims made in real life and use data to determine the truth behind the claim. The emphasis is on using appropriate calculations and representations rather than using every technique they know!

Since this is genuine real data, there are some avenues of exploration which will lead to a conclusion that there is a trend and others that are less fruitful in this respect.

Content covered can be tailored to the class and can include producing and interpreting:• Averages• Range• Bar charts• Line graphs• Box plots• Moving averages and trend lines (Extension)

Teacher notes: Freak Weather, or Not?

Slide 5: Discussions in pairs or threes.

Certain points are helpful to pick up on, or pose as questions if they don’t arise from student discussions.

What data do you need?• What variables would you look at? (temperature, rainfall/precipitation, humidity)• More precisely… Would you need annual temperature? Might you look at maximums and/or

minimums? Would you choose a certain month? Should you look at the whole of the UK or choose certain areas?

How much of a difference is a ‘real’ difference?• This is a question with no ‘right’ answer, at this level, but just to convey a sense of a couple of

degrees warmer one year compared to the previous year is not as persuasive as a degree warmer for a prolonged period.

.

Teacher notes: Freak Weather, or Not?Slides 6 to 10: Met Office maps

These slides show the annual temperature for the UK for 30 year periods.• Because it’s the annual temperature, we have no idea whether it is:

– A small increase in temperature every month– Winters the same but summers quite a bit warmer– Winters are colder but summers are much hotter

Why look at blocks of 30 years?• Using a ‘time series’ approach is less affected by the variation in individual years• It is easier to spot emerging trends• It is more persuasive than looking at individual year variation

Understanding this will be helpful for students when they explore the data.

Slide 11

Small group discussion.

Question: How might we represent the data differently to gain a clearer insight? • Look at averages for decades instead of each year• Compare summer temperatures and compare winter temperatures• Compare box plots for each decade• Consider moving averages and trend lines (extension work)

Teacher notes: Freak Weather, or Not?Slides 12 and 13: working on a question• You might ask different groups to work on different questions to build a bigger general picture

about climate change.• The emphasis is on using appropriate statistical techniques, relevant to the question they are

exploring – regardless of whether they use pencil and paper or ICT to construct or calculate.• The data for the questions can be explored using data from the accompanying Excel file. • Using ICT does allow a more thorough exploration of the data in a timely manner. • If students don’t have access to ICT facilities, then it is helpful to select and print a reduced range

of data for students to use.• If students pose their own questions, more data are available on the Met office website (links on

last slide) • A sheet for planning and summarising is attached.• A sample selection of summary data and charts is also attached for Teacher reference.

Teacher notes: Freak Weather, or Not?Acknowledgements and links:

Met office maps: http://www.metoffice.gov.uk/climate/uk/averages/ukmapavge.html

Frozen Thames 1963 photo: http://www.thamesweb.co.uk/windsor/windsorhistory/freeze63.html

Women at standpipe 1976 photo: http://news.bbc.co.uk/1/hi/magazine/6729465.stm

Parker, D.E., T.P. Legg, and C.K. Folland. 1992. A new daily Central England Temperature Series, 1772-1991. Int. J. Clim., Vol 12, pp 317-342 http://www.metoffice.gov.uk/hadobs/hadcet/data/download.html

Alexander, L.V. and Jones, P.D. (2001) Updated precipitation series for the U.K. and discussion of recent extremes, Atmospheric Science Letters doi:10.1006/asle.2001.0025.

http://www.metoffice.gov.uk/hadobs/hadukp/data/download.html