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Students should be able to illustrate how earth processes and human factors influence Earth’s climate, evaluate effects of
climate change and initiatives that attempt to address those effects

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Earth and Science - 6
Chemical World - 10
Physical World - 6, 8
Biological World - 10
Nature of Science - 2, 5, 6

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Why I selected these links to other LO's

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Why I selected these links to other LO's

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This LO links to all of the key skills required for successful learning by the student.

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Developments in your thinking in relation to the Specification

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Sciene Collaborative Planning Document - non-interactive

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This lesson plan is associated with this LO.

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This shows how companies are using science based targets to reduce their contribution to global warming.

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We spoke to some of the companies who have set science-based targets about why they have chosen to do so. They explain how they got buy-in to the targets, the benefits and some of the innovations that are helping them achieve their goals.

Landsec is the largest commercial property company in the UK and a member of the FTSE 100. Founded in 1944, Landsec owns and manages more than 23.6 million square feet of property, worth £14.6bn. Its focus is London oﬃces, and UK retail and leisure. Its portfolio includes the iconic 20 Fenchurch Street, also known as the 'walkie-talkie'. Read more about Land Securities science-based target.
Read more about Landsec's science-based target here.

Sony Corporation is a leading manufacturer of audio, video, imaging, game, communications, key device and information technology products. With its music, pictures, computer entertainment and online businesses, Sony is uniquely positioned to be the leading electronics and entertainment company in the world. Read about Sony's science-based target.

Thalys is an international train operator, running trains on the high-speed line between Paris, Brussels, Amsterdam and Cologne, also serving Lille, Rotterdam, Dusseldorf, Essen and Dortmund. Thalys trains carry over 6.5m passengers. Read more about Thalys's science-based target.

Edge Environmentis a sustainability consultancy based in Australia and Chile. "We're committed to taking an evidence-based, life-cycle approach to tackling sustainability problems. It is this approach that underpins our own science-based targets and the work we do with clients looking to improve their triple bottom line sustainability."Read more about Edge's science-based target.

Origin Energy is an integrated Australian energy company, operating across power generation, energy retailing and natural gas exploration and production. As Australia's largest energy retailer, Origin has approximately 4.2 million customers across its electricity, natural gas and LPG businesses. "Our target will help us deliver our primary goal of getting energy right for our customers, our communities and the planet." Read more about Origin Energy's science-based target.

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We spoke to some of the companies who have set science-based targets about why they have chosen to do so. They explain how they got buy-in to the targets, the benefits and some of the innovations that are helping them achieve their goals.

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Peer reviewed article/science pedagogy:                         Teacher interventions in small group work in secondary mathematics and science lessons.

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Peer reviewed article/science pedagogy:                         Teacher interventions in small group work in secondary mathematics and science lessons.

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This study helped me to understand the benefits of using group work to help students come up with their own ideas first and contribute their ideas through presentation to the whole class.

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ABSTRACT
Collaborative problem solving, when students work in pairs or small groups on a curriculum-related task, has become an increasingly common feature of classroom education. This paper reports a study of a topic which has received relatively little attention: how teachers can most usefully intervene when students are working in a group, but have encountered some sort of problem. The data used comes from a large-scale interventional study of mathematics and science teaching in secondary schools in south-east England, in which interactions between teachers and students were recorded in their usual classrooms. We identify the typical problem situations which lead to teachers' interventions, and describe the different ways teachers were observed to intervene. We examine the different types of intervention, and consider how effective they are in helping group work proceed in a productive manner. Finally, we offer some conclusions about the practical implications of these findings.

Introduction

Research suggests that collaborative activity can be effective in promoting students' learning, and group work has become increasingly common in classrooms throughout the world (Galton and Hargreaves ; Howe ; Mercer and Littleton ; Slavin ). However, while group work is potentially very productive, it commonly is not: and students often find engaging in collaborative work difficult (Baines, Blatchford, and Kutnick ; Galton et al. ; Howe and Abedin ). Three aspects of group work have been considered central for success. The skill to work collaboratively is well recognized as an important condition for productive group work (Gillies ; Mercer et al. ; Scott, Mortimer, and Aguiar ). Productive group work also requires tasks that are suitable for being tackled collaboratively (Cohen ; Hofmann 2008 . 2008. "Ownership in Learning: A Sociocultural Perspective on Pupil Engagement, Collaboration and Agency in the Classroom." Unpublished PhD diss., University of Cambridge. ; Howe and Abedin ). This paper focuses on a third important condition for supporting group discussions, how teachers manage group work in their classrooms, which remains under-researched (cf. Bennett et al. ; Osborne et al. ; Webb et al. ). Despite a reasonable body of evidence about how students should behave for group work to be effective, there is considerable vagueness and uncertainty about how teachers can best support and sustain subject-based discussions in groups. And while some research suggests that groups are most likely to be productive if teachers avoid intervening (Howe ), there is little doubt that if teachers simply leave groups to struggle a lot of educational time will simply be wasted.

The study reported addresses these issues with regard to group-based activity in secondary science and mathematics lessons, focusing on the role of the teacher as a monitor and guide for students' collaborative activity once it is underway. This study is part of the Ruthven, K., N. Mercer, K. Taber, P. Guardia, R. Hofmann, S. Ilie, S. Luthman & F. Riga (forthcoming). "A research-informed dialogic-teaching approach to early secondary-school mathematics and science: the pedagogical design and field trial of the epiSTEMe intervention." epiSTEMe (Effecting Principled Improvement in STEM Education) project (Ruthven et al. forthcoming Research Papers in Education. ), in which a research-informed pedagogical intervention programme was created to encourage mathematics and science teachers to use more 'dialogic' strategies (Alexander ; Mortimer and Scott ). The teachers involved taught students in Year 7 (11-12 years), the first year of secondary education in the English system. At the start of the project, each class took a module involving practicing discussion skills and developing class 'ground rules' for talk (Mercer et al. ; Mercer and Littleton ). Based on a synthesis of international research on effective pedagogy in science and mathematics, the intervention also drew on the notion of using carefully crafted authentic problems to encourage students to engage more deeply with the conceptual issues in both whole-class discussions and group activity (Ruthven et al. ; Ruthven and Hofmann ; Taber et al. ; Howe et al. ).

The collaborative group work in the epiSTEMe pedagogic approach entails that students work together on the task as a group to reach, through discussion, a group outcome on which all members agree. Group work serves as an exploratory phase for subsequent whole-class discussion; its purpose is the emergence of multiple student-initiated ideas which can be discussed in subsequent whole-class dialogue (Ruthven, Hofmann, and Mercer ), hence enabling students to come up with their own ideas about the task is central.

Teachers' pedagogical interventions to support small-group work: realities and challenges

A body of evidence suggests that, for group discussion to be productive, students should share their ideas and support them with reasons, discuss different views and resolve these to achieve group consensus (Howe ; Mercer and Howe ; Littleton and Howe ; Mercer and Littleton ; see also Bennett et al. ; Kyriacou and Issitt ). However, this research also suggests that such characteristics of group discussions are not commonly found in classrooms, and that teachers find managing group discussions difficult. The question arises as to whether teachers' habitual ways of intervening in small-group work enable students to make better sense of a set task and/or encourage the kinds of productive dialogue which will help them gain the most from their collective thinking.

Research findings on what teachers should do to support these processes during group work are divergent. Several studies suggest that teachers should withhold queries regarding the content of the task and instead ask general questions, such as inviting contributions (Baines, Blatchford, and Chowne ; Blatchford et al. ; Myhill ). It is thought that teacher engagement with problem content increases dependence on the teacher and removes students' autonomy and initiative with the task (Cohen b cited in Chiu ; cf. also Howe, Tolmie, Duchak-Tanner & Rattray ). Chiu (, 367) concludes that 'teachers who use questions to provide minimal problem content information can improve students' CL [cooperative learning] by bolstering their autonomy, initiative and interdependence'.

Other research, particularly on mathematics lessons, has found that non-content specific questions do not lead to students providing explanations (Franke et al. ; Henningsen and Stein ; Kyriacou and Issitt ; Meloth and Deering ). Henningsen and Stein () and Meloth and Deering () found that when teachers did not provide students with enough information, students were not able to discuss the task meaningfully. Henningsen and Stein argue that to maintain a high cognitive level in students' discussions and explaining, teachers need to model high-level performance and avoid removing the challenging aspects of the task. Webb et al. () also found that one of the strongest influences on how students talk together in groups is how their teacher talks with them.

Similarly, some authors have proposed avoiding immediate evaluation of students' contributions, arguing that to maintain high-quality discussions in groups, teachers need to focus on promoting the development of understanding rather than just the identification of correct answers (Henningsen and Stein ; Kyriacou and Issitt ; Myhill ; Rojas-Drummond and Mercer ). On the other hand, Chiu () found that when teachers evaluated students' ideas during group work, students were more likely to engage with the task than in the absence of evaluation. Chiu suggests that non-evaluative teacher interventions to a group were ineffective because they were not contingent on the group's current needs.

We suggest that these different views on what makes teacher interventions effective reflect the current limited state of understanding about these matters. Content-specific support may link with students' current needs and may help them reach a correct solution, but may come at a cost of reducing their own independent thinking and reasoning about the task. On the other hand, non-content specific feedback allows for student autonomy but may not be sufficient for helping students make progress. We suggest that teachers' interventions in small-group work need to be contingent on any difficulties that the students are encountering, but without inducing dependence on the teacher, (i.e. without removing the need for students' own collective thinking to achieve a proposed resolution). However, it is clear that we do not yet know what such interventions could look like in real mathematics and science classrooms. This is the focus and contribution of our current study.

Studies of existing classroom practice indicate that teachers' interventions during group work are usually prescriptive, focused on procedures and performance, and generate high student dependence on the teacher. Students' contributions are typically evaluated immediately; correct ideas proposed by students are accepted at face value (without seeking further justification), whereas incorrect student contributions are ignored and the thinking behind them rarely probed (Chiu ; Henningsen and Stein ; Mercer, Dawes, and Staarman ; Webb et al. ; Webb, Nemer, and Ing ). Webb and colleagues (, 109) speak of an 'entrenched culture of low-level questions and explanations' in (mathematics) classrooms. Researchers have found that getting teachers to change such established practices is difficult (Osborne et al. ; Webb et al. , ). Gillies and Khan () found that professional development training needed not only offer new strategies for intervention, but also to raise teachers' awareness of the purposes of group work. We suggest that it may be useful to take one step back from trying to change teachers' behaviour, and consider why they may intervene in group work in such ways.

Understanding the sociocultural norms and goals of classroom discussions

The ultimate aim of our analysis is to identify ways in which teachers can most usefully intervene in group work in mathematics and science classrooms, so that this can inform teachers' actions and teacher education. To present such different ways as simply alternatives which teachers could choose on any occasion would be naïve, and would ignore the practical reasons why teachers develop and maintain some of the interactional strategies that they do. We therefore need to examine the kinds of difficulties teachers may have in abandoning habitual strategies, and the culture within which those are embedded, which may make the take-up of new strategies difficult, or even stressful. We will argue that any proposals for change must take account of the temporal, conversational and activity structure of classroom life. To illustrate these aspects of the use of spoken language in classrooms, we will draw on theoretical approaches to education which recognize the role of language and sociocultural practice in learning.

Research on classroom interaction has established how classrooms are particular sociocultural settings, with their own norms and rules which are common knowledge to all participants (Edwards and Mercer /2013). These norms inform and shape teachers' existing practice in ways that can make the take up of new pedagogic strategies difficult. For example, research has illustrated how in classroom interactions, both teachers and students expect that teachers offer evaluative feedback on students' contributions. Such normative expectations are not simply 'bad habitual responses' of the teachers, but criteria for actions perceived as 'appropriate' by all participants in those cultural situations (Edwards and Mercer /2013; McHoul ; Sinclair and Coulthard ). Such expectations cannot be simply ignored if participants are to remain able and motivated to take part. Such implicit contextual frameworks are often quite well established, and so they can make it difficult to change the ways teachers and students interact, even if there are good educational reasons for seeking such changes (Hofmann 2008 . 2008. "Ownership in Learning: A Sociocultural Perspective on Pupil Engagement, Collaboration and Agency in the Classroom." Unpublished PhD diss., University of Cambridge. ; Rainio and Hofmann ).

It is for these reasons we argue that researchers need to pay attention to what the participants in a social practice are trying to . 2010. do through their interactions (Daniels ; Mercer ; Hofmann 2008 . 2008. "Ownership in Learning: A Sociocultural Perspective on Pupil Engagement, Collaboration and Agency in the Classroom." Unpublished PhD diss., University of Cambridge. ). Research suggests that teachers actively monitor groups and decide when to intervene (Chiu ), and we argue that understanding these decisions better would be helpful for considering the possibility of change. Culturally and historically formed practices, including classroom teaching, are motivated by the 'problem spaces' at which we oriented our actions within those practices (Edwards 2010 Being an Expert Professional Practitioner: The Relational Turn in Expertise. Vol. 3. Springer Science & Business Media. ). What we are suggesting is that any intervention which is to have a possibility of changing such established practices must take into account what the participants are trying to get done, what problems they are trying to work on and improve.

Research questions

Our analysis of teacher interventions in small-group work on the epiSTEMe mathematics and science problems addresses the following research questions:

1. In what kinds of situations do teachers intervene in groups, and why do they do so?

2. What strategies did the teachers we observed in the epiSTEMe project use when intervening in group work?

3. In what ways and to what extent are teachers' intervention strategies contingent on students' current understandings/discussion and what scope do they offer for enabling students' own thinking and ideas?

4. What evidence might be available to a teacher, during or after an intervention, about the effects of any strategies on students' behaviour?

Data and methods

The epiSTEMe intervention programme was designed to enable teachers of mathematics and science in English secondary schools make more effective use of dialogue in teaching their subjects in the context of rich tasks, and discussed and piloted with a group of participating teacher collaborators. The content of the intervention programme has been described in detail elsewhere (Ruthven et al. ), and such detail is not directly relevant to our concerns here. In summary, the materials consisted of four topic modules each containing a series of fully-developed lessons, inclusive of projection slides, teaching notes and student booklets, with carefully crafted activities for small-group and whole-class discussion. The group activities were designed to draw out differences of perspective relevant to the topic-related problem among members of a group, which could then be debated in the pursuit of an agreed solution. The aim was to get students thinking about the topic, bring out their thinking and enable the emergence of multiple common ideas and misunderstanding about the topic to be discussed in a subsequent whole-class dialogic plenary (see Ruthven and Hofmann ). The intervention teachers all received the materials and two days of professional development by the epiSTEMe team. The professional development provided to the participating teachers as well as the teaching materials for the project included specific suggestions for ways to guide and prompt students' discussions (drawing on research such as that described in Mercer and Littleton ; Galton and Hargreaves ; Howe ). It was made clear to participating teachers that an important aspect of their role in relation to such group work was to encourage students to use talk effectively for collaborative problem-solving (Ruthven, Hofmann, and Mercer ).

We observed 10 mathematics and 2 science teachers from the pilot and main intervention phases of the project, distributed across 8 schools. This yielded audio and video data of lessons (approximately 60 min each, 18 hours in total), as well as observation notes made in-situ by the first author. Descriptive summaries were first constructed of each lesson based on the field-notes and recordings. The analysis focused just on those 'episodes' in lessons when a teacher joined a group, and we define an episode as the total time the teacher spent with a group on any one occasion.

The analysis identified a total of a 104 episodes of teacher visits to small groups totalling over three hours of recorded data, with the average duration of a teacher intervention in a group around 2 min. Sixty-nine episodes found to contain interactive data were transcribed and analysed for their turn-by-turn interactions with the aim of identifying the specific interactive strategies used by teachers and their apparent communicative consequences during the teacher's visit. Each interactive move was compared to preceding and subsequent interactive moves, and each episode was repeatedly compared to other episodes in the same overall category and to other categories, including deviant cases, until there was sufficient evidence that a category was both robust and distinctive enough. The episodes were also analysed for the different 'problem situations' that they may have posed for the teacher. While the bulk of the analysis was conducted by the first author, for reliability and validity of the coding, both authors separately coded parts of the data set and compared results. Disagreements were resolved by discussion, and the refined categories re-applied across the data-set. Only strategies used at least by two teachers were included to ensure the reported strategies are not simply part of an individual teacher's personal style and repertoire. In fact, each discussed strategy was used by at least 5 different teachers, in at least 13 episodes.

Results

We will discuss and illustrate our findings through presenting two whole episodes (one from mathematics, one from science) as well as some further brief examples.

What kinds of situations arising during group work provoke teachers to intervene?

One of our aims was to identify the kinds of problematic group situations arising in the observed classrooms that provoked teachers to make a significant intervention. We observed that, on several occasions, the teachers joined a group just to check that the group was working, or to find out whether they had finished. No further interaction then ensued, and so such interactions are not included in our analysis. In 69 episodes, more prolonged interaction between the teacher and student took place. We closely examined and compared the starting situations in these episodes which the teacher faced upon entering the group. Our analysis suggests that these episodes fell into three types of situations in which a group was proposing

no ideas (illustrated by Example 4 below),

an incorrect idea (Example 3) and

a correct idea or solution (Example 2).

We suggest that it is worth noting how these different starting situations, as identified by our analysis of the discourse, relate to those identified by our participating teachers in their informal comments about implementing group work in the classroom.

We compared this analysis with comments from our participating teachers, who also identified broadly the three same categories. However, the teachers' conceptions of what was 'problematic' about these situations differed from ours. . 2004. "Adapting Teacher Interventions to Student Needs During Cooperative Learning: How to Improve Student Problem Solving and Time On-Task." , , V. Duchak-Tanner, and . 2000. "Hypothesis Testing in Science: Group Consensus and the Acquisition of Conceptual and Procedural Knowledge." Students not proposing ideas was related by the teachers to the need to get the students working, while for us it was primarily a challenge of getting them thinking. Students proposing a correct idea or solution was typically perceived as problematic by teachers if it happened early during group work, because this would mean the group had nothing left to do while other groups worked on. Teachers did not raise our concern, which was whether this might mean that not everyone in the group understood why an idea was correct. Whereas students proposing incorrect ideas or answers was typically perceived by teachers as a problem requiring the teacher's active and immediate help (one of the teachers said: ' It is not my job to make students discuss incorrect ideas, it is my job to help them get it right'). In our view, on the other hand, the discussion of all relevant (even if incorrect) student ideas might be beneficial for the development of their understanding. The teachers' comments are in accord with prior research findings about mathematics and science teaching (Chiu 2004 2000 Learning and Instruction 10 (4): 361-391. ), and illustrate the kinds of problems teachers think their intervention strategies are expected to address. We will return to these matters in discussing our results. American Educational Research Journal 41 (2): 365-399. ; Howe et al.

All observed interactions were initiated by the teachers in two broad ways - a 'closed' way and a relatively more 'open' way. In 13 episodes (involving three different teachers), the teacher immediately began leading the students through the correct procedure for solving the problem. However, in 54 episodes, the teacher, at least initially, began a more open discussion about the task/solution process and invited students to contribute to it. Given our discussion about typical teacher responses to small-group work revealed by previous studies, this makes our data-set worthy of closer examination. (In the two remaining episodes, the teachers commented on an issue not related to the task, such as homework.)

What strategies did the intervention teachers in our project use when intervening in group work?

Authoritative strategies

In some episodes, the teacher initiated the interaction by taking the lead in the solution process. In some episodes, the teacher simply accepted a correct answer from a student at face value with no further probing, or led them through every step of the solution procedure, without exploring students' understanding.

Example 1

A4. S(1): Three

A5. S(2): Out of four?

A7. S(1): Four

A8. S(2): No, three.

[Probability_HS]

The sequence in Example 1 describes a group work situation in which two students each suggest a different answer, which represent the correct (A7) and an incorrect (A4, A8) answer respectively. The teacher ignores the incorrect answer (A6) and accepts the correct answer at face value (A9) without exploring students' thinking behind their different suggestions, thereby also closing down an opportunity for discussion. The teacher's intervention strategy maintains high teacher dependence during the search for a solution. The teacher also ignores two students' apparent misunderstanding (A4, A8). The teacher regulates both the form and content of the talk and does not invite students to actively think about the task: rather, the task is constructed as one of simply speaking the correct answers.

However, some of the interactions the teachers initiate with students who seem to be 'stuck' involve more engagement with the task content and students' thinking, even if the teacher maintains a regulative role over both form and content of talk. In Example 2, students express uncertainty but nonetheless present a correct answer ('statement R is incorrect') on Line B2.

Example 2

B1. T: Yes, lads.

B6. S1: Yeah.

B8. S1: One in six.

B9. S2: Unlikely.

[Probability_ FN]

In this interaction, the teacher repeats the answer offered by a student and asks the students to provide an explanation (B3). One student provides a partial correct answer (B4) which the teacher confirms as correct and asks for the missing information (B5, B7). Student 1 provides an answer (B8) which the teacher confirms as correct (B10). Another student provides an incorrect answer ('unlikely', B9) which the teacher ignores (B10), and moves on. In this episode, as in Example 1, the teacher still controls the structure and content of the talk. He does, however, probe the students' responses in a way that can be described as contingent (that is, it takes account of the disparity of views offered by the group members). Nevertheless, the regulation of the problem-solving process remains firmly in the hands of the teacher.

Initiating strategies

However, in the majority of the episodes the teachers did not take an immediate, authoritative lead in the solution process; and it is those episodes that we will discuss in the remainder of this section. We will first deal with how teachers initiate interactions with groups and then look at how they subsequently interact with students. We suggest those are core moments, pedagogically, wherein teachers have to make decisions about what to do, and in which the scope of the potential subsequent interaction is defined. We will present two longer episodes (Examples 3 and 4) and then discuss the strategies used by teachers in these episodes and across the data-set. In these episodes, the teachers do not immediately take over the problem-solving. Instead, they initiate the interaction with the group by using one or more of the following opening strategies:

1. inviting students to speak (Example 3);

2. listening silently to the discussion (Example 3);

3. making reference to the 'ground rules' of the activity (Example 4); and

4. focusing students on the task (Example 4).

In Example 3, it can be seen that the teacher invites the students to speak and listens silently and intently over several student turns while the students share their ideas and thinking at quite some length, reporting on a discussion they have had. In Example 4 (below), the students are stuck and initially not making any contributions. The teacher begins by making a general reference to one of the 'ground rules' that have been established in a previous lesson, that 'students are expected to decide on a shared answer'. After the teacher focuses the students on, and clarifies, their task, it can be seen that they go on to contribute relevant (if initially mathematically incorrect) ideas to the discussion.

Example 4

D2. S: Nothing.

D3. S: That I'm stuck.

D6. S: Everything.

D10. S: 1 in...

D12. S: 1 in...

D13. S: 4.

D14. S: ... 4.

D16. S: Yeah.

D18. [Overtalking]

D20. S: It's 1 in...

D22. S: It's not equal.

D24. S: It's not equal.

D27. S: That it's not...

D30. S: Probably.

D31. S: If it's bigger.

D33. S: No.

[Probability_IB]

There are many examples of use of such strategies across different lessons and teachers in our data. The teacher's reference to established ground rules in Example 4 is particularly interesting because it shows how a teacher can encourage a group to think about they might most productively interact to solve the problem. Prior research has shown that by establishing such rules, a teacher can encourage students to adopt ways of regulating their activity to make group discussion most productive (Mercer et al. ; Mercer and Littleton ). Other examples of references to ground rules in our data are:

[ 'Read a bubble out and then have a chat about it and see whether or not altogether you all agree or disagree.'] [ 'Okay, you all agree B, do you?'; 'What have you decided on this table?'] [ 'Who's got any ideas at all?'; 'You don't understand, who understands?'; 'Anyone want to help your team member?'] [ 'Go on, what were you going to say?']

Listening intently to what students say without immediately responding is also a way teachers can encourage students' discussions, illustrated on Lines C2-C5 in Example 3. Sometimes, teachers emphasize that their silence is not meant to imply criticism: 'I'm just listening'. Or teachers may focus students on the task at hand by reading the task out loud or asking students to read it out. But they also use more active strategies of focusing students on the task, such as asking students to explain the task, as in D4 and D7 in Example 4. If students say they do not understand, the teachers sometimes ask what students do not understand ( 'Tell me what it is you don't understand?').

Continuing interactive strategies

In the episodes in which teachers continue to encourage student discussion of ideas, we have observed four core strategies which teachers employed once they have begun interacting with a group in ways which do not involve closing down the discussion:

1. repeating relevant ideas expressed by students;

2. probing and exploring students' understandings;

3. encouraging students to compare and test ideas; and

4. identifying resources for thinking.

An example of a teacher repeating relevant ideas expressed by students is illustrated in Line C8 in Example 3, thus highlighting their relevance to the discussion (not necessarily indicating their correctness). Teachers also sometimes asked students to repeat what another group member had said - as illustrated on Line D21 in Example 4. They also sometimes reformulated what a student had said, so as to clarify it:

Example 5

[Probability_IE]

Such strategies have long been recognized as common in whole-class interactions (Edwards and Mercer /2013). Moreover, teachers sometimes probed and explored students' understandings behind the ideas and answers they offered. For example:

Why do you think that?

Convince me!

In Example 4, this is illustrated in Line D23 when the teacher asks the student to explain her thinking.

The teachers in the data also encouraged the students to compare and test ideas themselves, for example, by asking for others' perspectives and by asking others to comment on the idea of a group member, or by asking a student to explain an idea proposed by a group member, as in Lines D21-D26 in Example 4. This can help students notice that they have different ideas that could usefully be discussed and compared. This strategy is specifically illustrated in Example 6.

Example 6

[Probability_EB]

Finally, another strategy identified is to make available to students additional relevant resources for thinking about the problem. This can mean providing students with additional mathematical or scientific information relevant to the task, without taking them through the solution strategy (such as 'the probability of 1 means certain'). They may direct students to consider a specific resource e.g. 'Do have any information that might help you?' or 'So what does the table mean? Why is the table there? Is that helping us at all?'. For example, in Example 7 in lines G1 and G3, a teacher refers to a mathematical tool that the students have encountered earlier in another task which could help them solve the current problem.

Example 7

G2. S(M): -Table.

[Probability_IB]

How may the strategies support students' thinking and how may this become visible for the teacher?

The teachers in our study used a variety of strategies to encourage students to express and discuss their ideas. Table 1 lists the types of problem situations which teachers were observed to encounter when joining a group of students, and also shows which interactive strategies teachers were observed to use in dealing with them.

Inviting students to speak (Examples 3 and 4) is a general, non-content specific strategy which prior research suggests is insufficient in encouraging a focus on understanding and explaining (Franke et al. ; Henningsen and Stein Henningsen, M. , and . 1997. "Mathematical Tasks and Student Cognition: Classroom-Based Factors that Support and Inhibit High-Level Mathematical Thinking and Reasoning." , and . 2008. 1997 2008 What Characterises Effective Teacher-Initiated Teacher-Pupil Dialogue to Promote Conceptual Understanding in Mathematics Lessons in England in Key Stages 2 and 3: A Systematic Review. London: EPPI-Centre, Social Science Research Unit, Institute of Education, University of London. ). However, it is an easy way of initiating interactions with the group that avoids the teacher immediately taking over the task. Furthermore, the ways it was done by some of the teachers we observed enabled them to highlight the importance of student-initiated ideas. It also gave the teacher the opportunity to find out what difficulties the students were facing, and enabled subsequent contingent responses (Examples 3 and 4). If students are not proposing any ideas, the strategy of asking them if they understand what they have been asked to do (Example 4) focuses their attention on the content of the task and allows the teacher to be helpful, without being prescriptive. Journal for Research in Mathematics Education 28: 524-549. ; Kyriacou and Issitt

The strategy of active listening (Example 3) can be considered contingent in that it does not disrupt students' current interactions and models the 'ground rule' of giving proper consideration to other people's ideas (Mercer and Littleton ; cf. Kyriacou and Issitt , and . 2008. . 2006. "Talk, Talk, Talk: Teaching and Learning in Whole Class Discourse." 2008 2006 Research Papers in Education 21 (1): 19-41. ). We have also observed teachers encouraging a group to strive for agreement in Example 3 (C14-C20). In response to such non-authoritative initiating strategies, students may subsequently elaborate their ideas at some length (Example 3), even if they were initially not discussing the task (Example 4). This may help a teacher recognize that such strategies are a good alternative to simply taking over the problem-solving process. What Characterises Effective Teacher-Initiated Teacher-Pupil Dialogue to Promote Conceptual Understanding in Mathematics Lessons in England in Key Stages 2 and 3: A Systematic Review. London: EPPI-Centre, Social Science Research Unit, Institute of Education, University of London. ; Myhill

Repeating ideas expressed by students (Example 3 C8; Example 4 D11; Example 5), probing students' understandings by asking them to explain further (Example 4 D23) and asking students themselves to compare and test ideas (Example 6) can function as contingent strategies that do not take over the authority from the students: they link with what students are currently discussing and suggesting while focusing students on understanding. Proposing resources for thinking (Example 7) can offer help that is targeted at students' current needs without evaluating their ideas or providing answers. It also guides students towards the useful heuristic strategy of looking for suitable resources to help their mathematical thinking in any situation.

Discussion and conclusions

Our study illustrates the range of ways teachers can intervene in students' group discussions in mathematics and science classrooms. Research on group work suggests that it is most productive for learning and the development of understanding if teachers 'model' effective ways of using talk to solve problems collectively, agree on suitable 'ground rules' for discussion with students, regularly remind students of those rules and (having set suitable tasks) allow students enough time to engage in thoughtful discussion (Howe ; Mercer and Littleton ; Slavin ). We have shown that some of the strategies used by the teachers we observed are compatible with those principles, while others are not. We also showed that teachers can intervene in group work in ways which are contingent on the difficulties students are facing at that point (which prior research has suggested is useful for promoting learning: Chiu ), without simply authoritatively providing or confirming a solution. One concern expressed to us by teachers is that a group which is 'stuck' on a problem may simply waste time if they are left to their own devices. Our analysis shows that some non-authoritative and non-evaluative strategies often are sufficient to help such groups to start proposing ideas and (re-)engage with the task. While we have no evidence from this study that some strategies promoted better learning outcomes than others, it seems reasonable to infer that those which encourage students to co-regulate their group work and bolster their 'autonomy, initiative, and interdependence' (Chiu , 347) are of pedagogical value.

In the early part of this paper, we also discussed the finding from prior research that teachers' habitual responses to classroom situations are difficult to change. Our perspective on this issue is that any proposal for changing teachers' current classroom practice needs to be embedded in an understanding of what motivates that practice, what purposes it serves. We drew on sociocultural and linguistic research to justify this view. We see practitioners' actions as oriented towards concrete and specific problems of practice (cf. Ruthven ). Teachers, like people in many demanding occupations, have to develop ways of dealing with problems as they arise. We have illustrated and applied this idea by framing our analysis of strategies by paying attention to what teachers themselves view as problems in group work, which any suggested new strategies must be capable of addressing. We have shown that some non-authoritative strategies can deal effectively with those situations that teachers see as problematic: supporting groups being 'stuck' or pursuing a wrong idea, or meaningfully occupying students who think they have 'got' the right answer straightaway. Earlier, we also reported that the reasons why teachers saw such situations as problematic were not the same as the reasons we had as researchers. Nevertheless, most teachers, we believe, would also welcome effective ways of getting students to re-engage with a task, to think more critically about ideas, to develop their own problem-solving abilities and not merely get the correct answer quickly but also be able to justify it. If we can show teachers that some of the non-authoritative interventional strategies identified in our study - as used by practising teachers like themselves, not merely being advocated by researchers - can serve to alleviate those kinds of problems and achieve other worthwhile educational aims, then they are likely to be seen as welcome additions to their repertoire of strategies. While different educational cultures prioritize talk in different ways (), reflecting upon the possibilities and local impact of changing established patterns of talk can be beneficial in any setting.

Acknowledgements

The authors wish to thank the Institute of Physics and the Economic and Social Research Council for funding the epiSTEMe project (RES-179-25-0003), fellow members of the research team (Ken Ruthven, Christine Howe, Keith Taber, Stephanie Luthman, Paula Guardia and Fran Riga) for their support; and the participating students and teachers for their enthusiastic engagement.

Disclosure statement

No potential conflict of interest was reported by the authors.

'Problem' situation

Interactive strategy

Students are not proposing ideas

Students are proposing incorrect ideas

Students are proposing correct ideas

References

Alexander, R.J . 2001. Culture and Pedagogy: International Comparisons in Primary Education. : Blackwell.

, , , , and . 2010. "Talking Science: The Research Evidence on the Use of Small Group Discussions in Science Teaching." International Journal of Science Education 32 (1): 69-95.

. 2010. Being an Expert Professional Practitioner: The Relational Turn in Expertise. Vol. 3. Springer Science & Business Media.

Henningsen, M. , and . 1997. "Mathematical Tasks and Student Cognition: Classroom-Based Factors that Support and Inhibit High-Level Mathematical Thinking and Reasoning." Journal for Research in Mathematics Education 28: 524-549.

. 2008. "Ownership in Learning: A Sociocultural Perspective on Pupil Engagement, Collaboration and Agency in the Classroom." Unpublished PhD diss., University of Cambridge.

, and . 2013. "Classroom Dialogue: A Systematic Review Across Four Decades of Research." Cambridge Journal of Education 43 (3): 325-356.

, and . 2008. What Characterises Effective Teacher-Initiated Teacher-Pupil Dialogue to Promote Conceptual Understanding in Mathematics Lessons in England in Key Stages 2 and 3: A Systematic Review. London: EPPI-Centre, Social Science Research Unit, Institute of Education, University of London.

, and . 1999. "The Role of the Teacher in Promoting Cognitive Processing During Collaborative Learning." In Cognitive Perspectives on Peer Learning, edited by and , 235-255. : Lawrence Erlbaum.

. 1995. The Guided Construction of Knowledge: Talk Amongst Teachers and Learners. : Multilingual Matters.

, and . 2012. "Explaining the Dialogic Processes of Teaching and Learning: The Value and Potential of Sociocultural Theory." Learning, Culture and Social Interaction 1 (1): 12-21.

, and K. Littleton. 2007. Dialogue and the Development of Children's Thinking: A Sociocultural Approach. : Routledge.

, , A. Christodoulou, C. Howell-Richardson, and K. Richardson. 2013. "Learning to Argue: A Study of Four Schools and Their Attempt to Develop the Use of Argumentation as a Common Instructional Practice and its Impact on Students." Journal of Research in Science Teaching 50 (3): 315-347.

. 2005. "Improving the Development and Warranting of Good Practice in Teaching." Cambridge Journal of Education 35 (3): 407-426.

, , and . 2011. "A Dialogic Approach to Plenary Problem Synthesis." In Proceedings of the 35th Conference of the International Group for the Psychology of Mathematics Education, edited by , Vol. 4, 81-88. : PME.

Ruthven, K., N. Mercer, K. Taber, P. Guardia, R. Hofmann, S. Ilie, S. Luthman & F. Riga (forthcoming). "A research-informed dialogic-teaching approach to early secondary-school mathematics and science: the pedagogical design and field trial of the epiSTEMe intervention." Research Papers in Education.

Additional information

Funding

Institute of Physics and the Economic and Social Research Council [grant number RES-179-25-0003].

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Teacher interventions in small group work in secondary mathematics and science lessons

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ABSTRACT Collaborative problem solving, when students work in pairs or small groups on a curriculum-related task, has become an increasingly common feature of classroom education. This paper reports a study of a topic which has received relatively little attention: how teachers can most usefully intervene when students are working in a group, but have encountered some sort of problem.

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This is a snippet of the presentation I used during micro-teaching. I used some facts from this.

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I used this during micro-teaching and thought it was an informative clip.

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I found some hard hitting facts in this article that I could share with my students.

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Climate change and challenges of water and food security

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Water and food security are the key challenges under climate change as both are highly vulnerable to continuously changing climatic patterns. Studies ...

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A good website to get some information on Irelands status with regard climate change

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This story is part of Planet or Plastic?-our multiyear effort to raise awareness about the global plastic waste crisis. Learn what you can do to reduce your own single-use plastics, and take your pledge.

Read this story and more in the June 2018 issue of National Geographic magazine.

If plastic had been invented when the Pilgrims sailed from Plymouth, England, to North America-and the Mayflower had been stocked with bottled water and plastic-wrapped snacks-their plastic trash would likely still be around, four centuries later.

If the Pilgrims had been like many people today and simply tossed their empty bottles and wrappers over the side, Atlantic waves and sunlight would have worn all that plastic into tiny bits. And those bits might still be floating around the world's oceans today, sponging up toxins to add to the ones already in them, waiting to be eaten by some hapless fish or oyster, and ultimately perhaps by one of us.

We should give thanks that the Pilgrims didn't have plastic, I thought recently as I rode a train to Plymouth along England's south coast. I was on my way to see a man who would help me make sense of the whole mess we've made with plastic, especially in the ocean.

Because plastic wasn't invented until the late 19th century, and production really only took off around 1950, we have a mere 9.2 billion tons of the stuff to deal with. Of that, more than 6.9 billion tons have become waste. And of that waste, a staggering 6.3 billion tons never made it to a recycling bin-a figure that stunned the scientists who crunched the numbers in 2017.

No one knows how much unrecycled plastic waste ends up in the ocean, Earth's last sink. In 2015, Jenna Jambeck, a University of Georgia engineering professor, caught everyone's attention with a rough estimate: between 5.3 million and 14 million tons each year just from coastal regions. Most of it isn't thrown off ships, she and her colleagues say, but is dumped carelessly on land or in rivers, mostly in Asia. It's then blown or washed into the sea. Imagine five plastic grocery bags stuffed with plastic trash, Jambeck says, sitting on every foot of coastline around the world-that would correspond to about 8.8 million tons, her middle-of-the-road estimate of what the ocean gets from us annually. It's unclear how long it will take for that plastic to completely biodegrade into its constituent molecules. Estimates range from 450 years to never.

Meanwhile, ocean plastic is estimated to kill millions of marine animals every year. Nearly 700 species, including endangered ones, are known to have been affected by it. Some are harmed visibly-strangled by abandoned fishing nets or discarded six-pack rings. Many more are probably harmed invisibly. Marine species of all sizes, from zooplankton to whales, now eat microplastics, the bits smaller than one-fifth of an inch across. On Hawaii's Big Island, on a beach that seemingly should have been pristine-no paved road leads to it-I walked ankle-deep through microplastics. They crunched like Rice Krispies under my feet. After that, I could understand why some people see ocean plastic as a looming catastrophe, worth mentioning in the same breath as climate change. At a global summit in Nairobi last December, the head of the United Nations Environment Programme spoke of an "ocean Armageddon."

And yet there's a key difference: Ocean plastic is not as complicated as climate change. There are no ocean trash deniers, at least so far. To do something about it, we don't have to remake our planet's entire energy system.

"This isn't a problem where we don't know what the solution is," says Ted Siegler, a Vermont resource economist who has spent more than 25 years working with developing nations on garbage. "We know how to pick up garbage. Anyone can do it. We know how to dispose of it. We know how to recycle." It's a matter of building the necessary institutions and systems, he says-ideally before the ocean turns, irretrievably and for centuries to come, into a thin soup of plastic.

In Plymouth, under the gray gloom of an English autumn, Richard Thompson waited in a yellow slicker outside Plymouth University's Coxside Marine Station, at the edge of the harbor. A lean man of 54, with a smooth pate rimmed with gray hair, Thompson was headed for an ordinary career as a marine ecologist in 1993-he was working on a Ph.D. on limpets and microalgae that grow on coastal rocks-when he participated in his first beach cleanup, on the Isle of Man. While other volunteers zoomed in on the plastic bottles and bags and nets, Thompson focused on the small stuff, the tiny particles that lay underfoot, ignored, at the high tide line. At first he wasn't even sure they were plastic. He had to consult forensic chemists to confirm it.

There was a real mystery to be solved back then, at least in academic circles: Scientists wondered why they weren't finding even more plastic in the sea. World production has increased exponentially-from 2.3 million tons in 1950, it grew to 162 million in 1993 and to 448 million by 2015-but the amount of plastic drifting on the ocean and washing up on beaches, alarming as it was, didn't seem to be rising as fast. "That begs the question: Where is it?" Thompson said. "We can't establish harm to the environment unless we know where it is."

In the years since his first beach cleanup, Thompson has helped provide the beginnings of an answer: The missing plastic is getting broken into pieces so small they're hard to see. In a 2004 paper, Thompson coined the term "microplastics" for these small bits, predicting-accurately, as it turned out-that they had "potential for large-scale accumulation" in the ocean.

When we met in Plymouth last fall, Thompson and two of his students had just completed a study that indicated it's not just waves and sunlight that break down plastic. In lab tests, they'd watched amphipods of the species Orchestia gammarellus -tiny shrimplike crustaceans that are common in European coastal waters-devour pieces of plastic bags and determined they could shred a single bag into 1.75 million microscopic fragments. The little creatures chewed through plastic especially fast, Thompson's team found, when it was coated with the microbial slime that is their normal food. They spat out or eventually excreted the plastic bits.

Microplastics have been found everywhere in the ocean that people have looked, from sediments on the deepest seafloor to ice floating in the Arctic-which, as it melts over the next decade, could release more than a trillion bits of plastic into the water, according to one estimate. On some beaches on the Big Island of Hawaii, as much as 15 percent of the sand is actually grains of microplastic. Kamilo Point Beach, the one I walked on, catches plastic from the North Pacific gyre, the trashiest of five swirling current systems that transport garbage around the ocean basins and concentrate it in great patches. At Kamilo Point the beach is piled with laundry baskets, bottles, and containers with labels in Chinese, Japanese, Korean, English, and occasionally, Russian. On Henderson Island, an uninhabited coral island in the South Pacific, researchers have found an astonishing volume of plastic from South America, Asia, New Zealand, Russia, and as far away as Scotland.

As Thompson and I talked about all this, a day boat called the Dolphin was carrying us through a light chop in the Sound, off Plymouth. Thompson reeled out a fine-mesh net called a manta trawl, usually used for studying plankton. We were close to the spot where, a few years earlier, other researchers had collected 504 fish of 10 species and given them to Thompson. Dissecting the fish, he was surprised to find microplastics in the guts of more than one-third of them. The finding made international headlines.

After we'd steamed along for a while, Thompson reeled the manta trawl back in. There was a smattering of colored plastic confetti at the bottom. Thompson himself doesn't worry much about microplastics in his fish and chips-there's little evidence yet that they pass from the gut of a fish into the flesh we actually eat. (See We Know Plastic Is Harming Marine Life. What About Us?) He worries more about the things that none of us can see-the chemicals added to plastics to give them desirable properties, such as malleability, and the even tinier nanoplastics that microplastics presumably degrade into. Those might pass into the tissues of fish and humans.

"We do know the concentrations of chemicals at the time of manufacture in some cases are very high," Thompson said. "We don't know how much additive is left in the plastic by the time it becomes bite-size to a fish.

"Nobody has found nanoparticles in the environment-they're below the level of detection for analytical equipment. People think they are out there. They have the potential to be sequestered in tissue, and that could be a game changer."

Thompson is careful not to get ahead of the science on his subject. He's far from an alarmist-but he's also convinced that plastic trash in the ocean is far more than an aesthetic problem. "I don't think we should be waiting for a key finding of whether or not fish are hazardous to eat," he said. "We have enough evidence to act."

How did we get here? When did the dark side of the miracle of plastic first show itself? It's a question that can be asked about many of the marvels of our technological world. Since helping the Allies win World War II-think of nylon parachutes or lightweight airplane parts-plastics have transformed all our lives as few other inventions have, mostly for the better. They've eased travel into space and revolutionized medicine. They lighten every car and jumbo jet today, saving fuel-and pollution. In the form of clingy, light-as-air wraps, they extend the life of fresh food. In airbags, incubators, helmets, or simply by delivering clean drinking water to poor people in those now demonized disposable bottles, plastics save lives daily.

In one of their early applications, they saved wildlife. In the mid-1800s, piano keys, billiard balls, combs, and all manner of trinkets were made of a scarce natural material: elephant ivory. With the elephant population at risk and ivory expensive and scarce, a billiards company in New York City offered a $10,000 reward to anyone who could come up with an alternative.

As Susan Freinkel tells the tale in her book, Plastic: A Toxic Love Story, an amateur inventor named John Wesley Hyatt took up the challenge. His new material, celluloid, was made of cellulose, the polymer found in all plants. Hyatt's company boasted that it would eliminate the need "to ransack the Earth in pursuit of substances which are constantly growing scarcer." Besides sparing at least some elephants, celluloid also helped change billiards from solely an aristocratic pastime to one that working people play in bars.

That's a trivial example of a profound revolution ushered in by plastic-an era of material abundance. The revolution accelerated in the early 20th century, once plastics began to be made from the same stuff that was giving us abundant, cheap energy: petroleum. Oil companies had waste gases like ethylene coming out the stacks of their refineries. Chemists discovered they could use those gases as building blocks, or monomers, to create all sorts of novel polymers-polyethylene terephthalate, for example, or PET-instead of working only with polymers that already existed in nature. A world of possibilities opened up. Anything and everything could be made of plastic, and so it was, because plastics were cheap.

They were so cheap, we began to make things we never intended to keep. In 1955 Life magazine celebrated the liberation of the American housewife from drudgery. Under the headline "Throwaway Living," a photograph showed a family flinging plates, cups, and cutlery into the air. The items would take 40 hours to clean, the text noted-"except that no housewife need bother." When did plastics start to show their dark side? You might say it was when the junk in that photo hit the ground.

Six decades later, roughly 40 percent of the now more than 448 million tons of plastic produced every year is disposable, much of it used as packaging intended to be discarded within minutes after purchase. Production has grown at such a breakneck pace that virtually half the plastic ever manufactured has been made in the past 15 years. Last year the Coca-Cola Company, perhaps the world's largest producer of plastic bottles, acknowledged for the first time just how many it makes: 128 billion a year. Nestlé, PepsiCo, and others also churn out torrents of bottles.

The growth of plastic production has far outstripped the ability of waste management to keep up: That's why the oceans are under assault. "It's not surprising that we broke the system," Jambeck says. "That kind of increase would break any system not prepared for it." In 2013 a group of scientists issued a new assessment of throwaway living. Writing in Nature magazine, they declared that disposable plastic should be classified, not as a housewife's friend, but as a hazardous material.

In recent years the surge in production has been driven largely by the expanded use of disposable plastic packaging in the growing economies of Asia-where garbage collection systems may be underdeveloped or nonexistent. In 2010, according to an estimate by Jambeck, half the world's mismanaged plastic waste was generated by just five Asian countries: China, Indonesia, the Philippines, Vietnam, and Sri Lanka.

"Let's say you recycle 100 percent in all of North America and Europe," says Ramani Narayan, a chemical engineering professor at Michigan State University who also works in his native India. "You still would not make a dent on the plastics released into the oceans. If you want to do something about this, you have to go there, to these countries, and deal with the mismanaged waste."

The Pasig River once flowed majestically through downtown Manila, capital of the Philippines, and emptied into pristine Manila Bay. It was a treasured waterway and civic point of pride. It's now listed among the top 10 rivers in the world that convey plastic waste to the sea. As many as 72,000 tons flow downstream each year, mostly during the monsoon. In 1990 the Pasig was declared biologically dead.

The Pasig River Rehabilitation Commission, established in 1999, is working to clean up the river, with some signs of success. Jose Antonio Goitia, the commission's executive director, says he is optimistic that the Pasig could be restored someday, although he acknowledges he has no easy way of doing that. "Maybe the best thing to do is ban plastic bags," he says.

The remaining challenges are clearly visible every day. The river is fed by 51 tributaries, some of them overflowing with plastic waste from squatter settlements that cantilever precariously over creek banks. A tributary near Chinatown, where rickety shanties are wedged between modern buildings, is so choked with plastic debris you can walk across it, forgoing the footbridge. Manila Bay's beaches, once recreational respites for greater Manila's 13 million residents, are littered with garbage, much of it plastic. Last fall Break Free From Plastic, a coalition including Greenpeace and other groups, cleaned a beach on Freedom Island, which is advertised as an ecotourism district; volunteers picked up 54,260 pieces of plastic, from shoes to food containers. By the time I visited a few weeks later, the beach was littered again with bottles, wrappers, and shopping bags.

The scene in Manila is typical of large, overcrowded urban centers across Asia. The Philippines is a densely populated nation of 105 million people that is still struggling with the most basic public health issues, including waterborne diseases such as typhoid and bacterial diarrhea. It's no surprise that it has trouble managing the explosion of plastic garbage. Manila has a metropolitan garbage collection system that stretches across 17 separate local governments-a source of chaos and inefficiency. In 2004 the region was already running out of land to safely dump garbage. The shortage of landfill space, and thus the crisis, continues today.

A small part of the slack is taken up by Manila's informal recycling industry, which consists of thousands of waste pickers. Armando Siena, 34, is one of them. He and his wife, Angie, 31, have lived their entire lives surrounded by trash. They were born on Smokey Mountain, an internationally notorious dump that was officially closed in the 1990s. They now live with their three children near Manila's waterfront in a one-room flat lit by a single bulb, furnished with a pair of plastic chairs, and lacking plumbing, bedding, or refrigeration. The flat is in a garbage-filled slum named Aroma, next to another slum named Happyland.

Every day Siena rides a rickety bicycle beyond Aroma's boundaries, scanning the streets for recyclable rubbish that he can stuff into his sidecar. Plastic soup containers are high-value finds, paying 20 pesos (38 cents) a kilogram. Siena sorts and sells his load to a junk shop owned by his uncle, who trucks the waste to recycling plants on the outskirts of Manila.

Waste pickers like Siena are part of the solution, some activists argue; they just need a living wage. In the Baseco waterfront slum in Manila, a tiny recycling shop operated by the Plastic Bank of Vancouver, British Columbia, pays a premium for bottles and hard plastic collected by waste pickers. It then sells that plastic at a higher price to multinationals, which market their recycled products as socially responsible.

Siegler, the Vermont economist, has worked in enough countries and run enough numbers to be skeptical of such schemes. "There is not enough value in plastics to make that work," he says. "It's cheaper to fund a solid waste management system than to subsidize collecting plastic."

The waste that clogs Manila's beaches and waterways reinforces Siegler's point. Much of it consists of sachets-tear-off packets that once held a single serving of shampoo, toothpaste, coffee, condiments, or other products. They are sold by the millions to poor people like Siena and his family, who can't afford to buy more than one serving at a time. Sachets blow around Manila like leaves falling from trees. They're not recyclable, so no waste picker will retrieve them. Crispian Lao, a member of the National Solid Waste Management Commission, says, "This segment of packaging is growing, and it has become a real challenge for solid waste management."

When Greenpeace cleaned the Freedom Island beach, it posted a tally of the brand names of the sachets its volunteers had collected. Nestlé ranked first, Unilever second. Litterbugs aren't the only ones at fault, says Greenpeace's Abigail Aguilar: "We believe that the ones producing and promoting the use of single-use plastics have a major role in the whole problem." A Unilever spokeswoman in Manila told me the company is developing a recyclable sachet.

After Malaysia Airlines Flight 370 disappeared from radar screens in March 2014 while on its way from Kuala Lumpur to Beijing, the search for it extended from Indonesia to the southern Indian Ocean. It captivated a global audience for weeks. No sign of the wreckage appeared. On several occasions, when satellite images revealed collections of objects floating on the sea surface, hopes soared that they would turn out to be aircraft parts. They weren't. It was all trash-pieces of broken shipping containers, abandoned fishing gear, and of course, plastic shopping bags.

Kathleen Dohan, a scientist and the president of Earth and Space Research in Seattle, saw opportunity in the horror: The images from space were pushing a problem into view that had long been neglected. "This is the first time the whole world is watching," she told me at the time. "It's a good time for people to understand that our oceans are garbage dumps." Dohan sensed a tipping point in public awareness-and the events since suggest she may have been right.

The most heartening thing about the plastic waste problem is the recent explosion of attention to it, and even of serious, if scattered, efforts to address it. A partial list of the good news since 2014 would include, in no particular order: Kenya joined a growing list of nations that have banned plastic bags, imposing steep fines and jail time on violators. France said it would ban plastic plates and cups by 2020. Bans on plastic microbeads in cosmetics (they're exfoliants) take effect this year in the U.S., Canada, the U.K., and four other countries. The industry is phasing them out.

Corporations are responding to public opinion. Coca-Cola, which also produces Dasani water, announced a goal to "collect and recycle the equivalent of" 100 percent of its packaging by 2030. It and other multinationals, including PepsiCo, Amcor, and Unilever, have pledged to convert to 100 percent reusable, recyclable, or compostable packaging by 2025. And Johnson & Johnson is switching from plastic back to paper stems on its cotton swabs.

Individuals are making a difference too. Ellen MacArthur, a British yachtswoman, has created a foundation to promote the vision of a "circular economy," in which all materials, including plastics, are designed to be reused or recycled, not dumped. Actor Adrian Grenier has lent his celebrity to the campaign against the plastic drinking straw. And Boyan Slat, 23, from the Netherlands, is charging ahead with his teenage vow to clean up the largest garbage patch in the North Pacific. His organization has raised more than $30 million to construct an ocean-sweeping machine that is still under development.

All of these measures help at some level-even beach cleanups, futile as they sometimes seem. A beach cleanup hooked Richard Thompson on the plastic problem a quarter century ago. But the real solution, he now thinks, is to stop plastic from entering the ocean in the first place-and then to rethink our whole approach to the amazing stuff. "We've done a lot of work making sure plastic does its job, but very little amount of work on what happens to that product at the end of its lifetime," he says. "I'm not saying plastics are the enemy, but there is a lot the industry can do to help solve the problem."

There are two fundamental ways industry can help, if it wants or is forced to. First, along with academic scientists such as Jambeck, it can design new plastics and new plastic products that are either biodegradable or more recyclable (see You Can Help Turn the Tide on Plastic. Here's How.). New materials and more recycling, along with simply avoiding unnecessary uses of the stuff, are the long-term solutions to the plastic waste problem. But the fastest way to make a big difference, Siegler says, is low tech. It's more garbage trucks and landfills.

"Everyone wants a sexy answer," he says. "The reality is, we need to just collect the trash. Most countries that I work in, you can't even get it off the street. We need garbage trucks and help institutionalizing the fact that this waste needs to be collected on a regular basis and landfilled, recycled, or burned so that it doesn't end up going all over the place."

That's the second way industry could help: It could pony up. Siegler has proposed a worldwide tax of a penny on every pound of plastic resin manufactured. The tax would raise roughly six billion dollars a year that could be used to finance garbage collection systems in developing nations. The idea never caught on. In the fall of 2017, though, a group of scientists revived the concept of a global fund. The group called for an international agreement patterned after the Paris climate accord.

At the Nairobi meeting in December, 193 nations, including the U.S., actually passed one. The United Nations Clean Seas agreement doesn't impose a tax on plastic. It's nonbinding and toothless. It's really just a declaration of a good intention-the intention to end ocean plastic pollution. In that way it's less like the Paris Agreement and more like the Rio de Janeiro treaty, in which the world pledged to combat dangerous climate change-back in 1992. Norway's environment minister, Vidar Helgesen, called this new agreement a strong first step.

Staff writer Laura Parker and photographer Randy Olson last worked together on a feature on the vanishing Ogallala aquifer, which was published in the August 2016 issue.

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We Depend on Plastic. Now We're Drowning in It.

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The miracle material has made modern life possible. But more than 40 percent of it is used just once, and it's choking our waterways.

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Found this online and thought it was an interesting way to visually show fuel burning.

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I showed students a snippet of this clip to prove that greenhouse gases are contributing to global warming.

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A nice website that I showed the students when they were beginning to research for their group presentation. Some nice activity ideas on this too organised categorically.

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Junior Cycle students

Energy in Action is a collection of online activities and ideas. We designed it to support the teaching and learning of energy and sustainability in the Junior Cycle. It is suitable for students of Science, CSPE, Geography and Home Economics.

An inquiry approach to energy and sustainability

These resources have been developed for use with an inquiry approach to education. They aim to enhance students' scientific knowledge, skills and competencies. The focus is on providing students with opportunities to consider and tackle problems that the future holds, e.g. sustainable practices in schools, homes and beyond.

A range of topics linked to our daily lives

It will develop young peoples' knowledge across a range of topics such as, energy sources, efficiency, conservation, climate change and global warming. These concepts will then be linked to students' daily lives.

Programme development

The programme was developed by the SEAI in collaboration with Junior Cycle teachers and CASTeL at Dublin City University.

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Energy in Action is a collection of online activities and ideas. We designed it to support the teaching and learning of energy and sustainability in the Junior Cycle. It is suitable for students of Science, CSPE, Geography and Home Economics. These resources have been developed for use with an inquiry approach to education.

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I did not use this directly but thought it was interesting and drew a few ideas from it

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Understanding Air: Climate Change and Modeling Combustion with LEGO® Bricks | PBS LearningMedia

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In this lesson, students learn about the components of air and the chemical reactions that release carbon dioxide into the atmosphere. They model combustion using LEGO bricks, and explore the connection between carbon dioxide, climate change, and environmental health.