Alice Deignan – Metaphors and ‘translations’ of science for school students

Metaphors and ‘translations’ of science for school students

Alice Deignanuniversity of leeds
University of Leeds

This post is about a recently finished research project on climate change and education that applies metaphor analysis in order to gain more insight about the ways in which school students in England understand climate change. It focuses on the greenhouse metaphor.

Climate change and young people

Two events sparked our interest in the topic. Firstly, in May 2013, concentrations of carbon dioxide went over 400 parts per million (now, at the time of writing, they are 404ppm (http://climate.nasa.gov). Before the Industrial Revolution, that figure was around 280ppm. This negative milestone coincided with a point when the English secondary school curriculum was being redesigned (Department for Education 2013, 2014). There was concern in Britain that climate change was not being given sufficient coverage in the new curriculum. For example, the Guardian newspaper covered the story under the headline “Climate debate cut from national curriculum for children up to 14” (https://www.theguardian.com/environment/2013/mar/17/climate-change-cut-national-curriculum). The lives of young people and their descendants may be marred by the results of climate change and we have a responsibility to communicate with them effectively. Research in the international Science Education community has consistently found that school children’s understandings of climate change are not strong (for example, 24 studies reviewed by Shepardson et al., 2014). Two of our team had already analysed metaphors of climate change in academic and popular texts (Deignan et al 2013, chapter 4), and so we decided to apply metaphor analysis to find out more about the understandings of climate change held by school students in England.

Metaphor and school science: data

Our project aims are to identify and compare the metaphors used to write and talk about climate change in three different kinds of text. The first of these is a corpus of academic and policy texts in the field of climate science, consisting of two parts: academic articles from the journals ‘Climate Change’, ‘Global Environmental Change’ and ‘Nature’, and policy documents, published by the Inter-governmental Panel on Climate Change and the UK’s Centre for Climate Change Economics and Policy, and Department for Environment, Food and Rural Affairs. This expert corpus consists of about 500,000 words. Secondly, we compiled a corpus of educational materials dealing with climate change, including website text, sections from school course books and other teaching materials. This corpus consists of about 250,000 words. Our third corpus consists of 90,000 words of transcribed interviews with school students aged between 11 and 16 years, at four secondary schools in Yorkshire, northern England.

The greenhouse metaphor

We found that many of the same metaphors are used by experts, in the educational materials, and by the young people in our interview data. In this post, I discuss just one of these. One of the most frequent metaphors used in all three corpora was, not surprisingly, greenhouse. On closer examination though, the metaphor is used in different ways. In the expert texts, it is used in a highly technical way, always before another noun, in phrases like greenhouse gases or greenhouse gas emissions. Greenhouse gases is abbreviated to GHG, again suggesting a highly technical meaning. Susanne Knudsen studied scientists’ uses of metaphors and concluded that they do not see them as metaphorical but as technical terms like any other (2003). In contrast, in the educational texts, writers actively encouraged students to think about the literal meaning of the word, for example:








In the interviews, the students refer to the literal meaning of greenhouse frequently. For example, one Year 8 student (aged 12-13 years) said:

my mum has a greenhouse so I kind of like refer back to that. It’s where like, because at certain heights the sun is able to get into like the glass.. it’s like, the earth is covered in like lots of glass panels but we just can’t see them, because the sun’s projecting into them. It doesn’t, it won’t come out, it’ll just keep coming in and when it tries to get out, it’ll just bounce off the roof and down in a continuous loop.

While it seems at first to be valuable pedagogically to encourage students to reflect in this way, we found that they over-generalise from the greenhouse metaphor, and draw some inferences that are not scientifically correct. In particular, many students hold the idea that carbon dioxide forms a thin, hard layer round the Earth like a pane of glass. How common this is is shown in the frequency of glass: it is nearly twice as frequent in this corpus as in a general language corpus, the British National Corpus, (relative to the size of the corpora), where it is usually used to refer to a container for a drink. This is the concordance for glass from the student interviews. Only citations 2, 4, 5, 6, and 8 do not show this use; the file numbers indicate that 4 of these are from the same interview.

KnipselThe first citation is from an interview with Year 7 students, who were aged between 11.5 and 12.5 years. Fuller context is as follows:

Interviewer What is the greenhouse effect?
Student 1 Er like in greenhouses, they trap err heat in for plants to erm stay warmer and all that, and that’s happening to the earth. The earth is like the plant, and the CO2 is making like a glass shelter around it, and it’s trapping heat in.
Student 2 We have greenhouse things because then, the plants, when you put plants in there, it helps it cos they don’t, they get like everything so they don’t get too much rain and too much sunshine, they have like a variety of different things
Student 3 It’s a mixture of different gases, it isn’t just one.
Interviewer What happens to the gases?
Student 1 They make a layer around the earth, like we’ve got atmosphere yeah they make a layer like the atmosphere, trapping all the heat in.

Here, students discuss several properties of greenhouses, that they keep plants warm, that they are made of glass, that they help to nourish plants because they help them to get the correct balance of ‘everything’, such as rain and sunshine. Only the first of these properties, that they trap heat, is the grounds for the greenhouse metaphor. This seems to represent a tendency among the students to extend metaphors creatively, using their knowledge of the literal meanings of the word, in a way that can lead to some misunderstandings. We found this in the use of a number of metaphors, throughout the student interviews.

In this case, it is also possible that the students are reinterpreting the diagrams of the greenhouse effect that they will have seen on websites and in their textbooks, such as this.


(licenced under Creative Commons)

Unfortunately, rather than developing and scaffolding understanding, the metaphors seem to limit it, and to lead to over-simplifications and misconceptions.


Our findings suggest that young people are very ready to engage with scientific texts and metaphors, and they enthusiastically bring their immediate, real world knowledge to interpreting what they read and hear. They readily extend metaphors creatively; in some of our interviews, they developed chains of metaphorical reasoning collaboratively with each other, unfortunately leading to scientific inaccuracy. We would suggest that materials writers and educators should be aware of this tendency to run with a metaphor, and could discuss the limitations of metaphors explicitly with young people.

Project information

This project was funded by a grant from the UK’s Arts and Humanities Research Council, grant reference AH/M003809/1, project title ‘Translating Science for Young People’. The project team consisted of myself, my colleagues at Leeds Dr Indira Banner, who is a science education researcher and Dr Shirley-Anne Paul, whose background is in reading and psycholinguistics, and from Lancaster University, Professor Elena Semino, who has used metaphor analysis to research communication in healthcare and other social issues. The project website is http://translatingscience.leeds.ac.uk. A more detailed description of the project and findings about other metaphors in the three corpora is in Deignan, Paul and Semino (submitted).


Deignan, A., Littlemore, J. and Semino, E. 2013. Figurative Language, Genre and Register. Cambridge University Press.

Deignan, A., Paul, S., and Semino, E. (submitted) ‘Metaphors of climate science in three genres: research articles, educational texts, and secondary school student talk’.

Department for Education. 2013. Reform of the National Curriculum in England. Report of the consultation conducted February- April 2013.

Department for Education. 2014. The National Curriculum in England: Key Stages 3 and 4 framework document. https://www.gov.uk/government/publications/national-curriculum-in-england-secondary-curriculum

Knudsen, S. 2003. Scientific metaphors going public. Journal of Pragmatics 35: 1247-1263.

Shepardson, D. P., A. Roychoudhury, A. Hirsch, D. Niyogi, and S. M. Top. 2014. ‘When the atmosphere warms it rains and ice melts: Seventh grade students’ conceptions of a climate system,’ Environmental Education Research 20: 333-353.