To Teachers: Global Warming Controversy -- Use Graphs to Stimulate Student Thinking

The week started with Evan’s* announcement that he had seen “An Inconvenient Truth” the night before and that he still wanted a car. I ran a quick poll. “How many of you want a car?”

Every thirteen and fourteen year old hand went up. Of course they all want a car! They live in a community with few sidewalks, very limited bus service and a town center that could best be described as “dispersed”. Global warming was on Luke’s mind because of his teacher’s upcoming trip to study climate change at the edge of the Arctic. In this same classroom two years earlier I’d brought reluctant eighth graders to take action to reduce their school’s contribution of greemhouse gases by organizing an effective recycling program. Now, with the support of the National Geographic Foundation, I was about to learn about climate change first hand by joining a research team on the shore of Hudson Bay.

This year my students are less resistant to learning about global warming. For one thing they know more. The media is finally reporting the concensus of the scientific community that our globe is warming and anthropogenic (human-caused) greenhouse gasses are a significant contributor to the trend. Another boost came from the thoughtful and sensitive reporting of the local media. Announcement of my trip coincided with a nearby school district temporarily banning “An Inconvenient Truth”. Suddenly it appeared as though I was putting my neck out to pursue a topic I thought was important. And my classroom was getting attention for it.

One of the first questions my students asked was “Why is An Inconvenient Truth controversial?” Reporters had asked me the same thing. Reporters and students alike got the same answer: pondering silence. I didn’t want to shut down their hope for change by simply telling them that it was just too inconvenient and that made people resistant: we'll look at barriers to change later. Neither did I want to frame the issue in terms of party politics, because it’s one that has to transcend all boundaries if we are to get anywhere with it. Neither of the two dominant parties has taken it seriously. It’s not about the difference between liberal and conservative, for liberal economic policies are what have increasingly opened up international transport of goods and thereby increased the production of CO2. What we need is some serious and very conservative conservation, and avenues that support youth to take action.

It wasn’t until I began thinking about how I would use the topic of global warming to teach math that I began to have an answer that was simultaneously open-ended, accurate, and focused enough to keep my students engaged. It would also, I hoped, help them recognize the power of their own thinking.

I proposed, “Al Gore does a great job interpreting a lot of graphs and telling you what to think about global warming. Maybe some people don’t like to be told what to think, and that’s why they don’t like the film.”

(Dr. Pete Kershaw explains climate change in Churchill. Come back in a few days and I'll have this graph and more to share.)


Then I showed them an episode of the film in which Gore interprets a graph of temperature and atmospheric CO2. Students can easily see that the lines fit together. (This is chapter 9 in the film; from about minute 20 - 25) Then Gore gets on a lift to illustrate that CO2 and temperature are going through the roof. After that, I played the TV news story in which I announce to the world that my students have the analytical skills to read and interpret graphs. I tied the two stories together by saying “Al Gore feels passionate about global warming, but you don’t need him to tell you what you think. You’ll be reading graphs and coming to your own conclusions tomorrow.”

That night I spent a half hour printing graphs from the International Panel of Climate Change’s just-released materials. (Available at http://www.ipcc.ch/present/graphics.htm. I’d love to tell you which ones too use, but a walk through them is fascinating and at least half of them would have worked for this activity. Large versions downoad fairly quickly even through a phone line. I printed eight in color for my classes of 30 - 34. I also used a few from the links on the Feb 4 post called "Graphs to Interpret")) Among them were average global temperatures, global distribution of CO2 generation, atmospheric CO2 levels, sea level, the global distribution of greenhouse gas emissions and shares of greenhouse gas emissions by industrial and economic sector. Taken altogether, the graphs represented a complex array of material. Scales of time differed vastly, as did units of measurement.

(This is a graph from the IPCC website linked to the left.)

In spite of the complexity, I felt my students could accurately interpret the graphs for two reasons: their algebra skills are strong, especially when it comes to visual representations; and their level of engagement with the topic was high.

Just to be on the safe side, I modeled a presentation for them. I chose a graph that showed the per capita CO2 emissions of twenty different nations. I held up the graph and interpreted it, “This graph seems to be saying that the US produces more CO2 per person than any other country in the world, except Luxumberg, and that it produces almost ten times the amount per person as China.” I was careful to use only the data on the graph, without adding any background knowledge.

They assembled in groups of four. One person selected the graph (first-come, first-serve -- always a motivator in a middle school classroom). Another person read all the words and numbers on the graph, while each group’s facilitator saw to it that everyone in the group could see the graph at all times and that the person elected to present the graph be ready in just five minutes. I gave students the phrase “This graph seems to be saying that . . . .” as a starting point.

Most of the conclusions they drew were not news to them. Two graphs however generated first silence, and then a flurry of questions. The first was a pie chart that showed that 23% of greenhouse gas emissions come from power generation. Alan jumped up and ran for the light and switched it off to a chorus of “One classroom at a time!” Then I walked over to turn off my computer monitor which was malfunctioning anyway. In our afternoon sun-brightened classroom, we next looked at a bar graph comparing total CO2 emissions from about 30 northern hemisphere nations. A group working on this graph had decided to add up the emissions starting with the least polluting and working up to the United States. They discovered that the total emissions of the bottom 25 countries combined still did not quite equal that of the United States.

This surprised many of them. Yes, they knew we are a fossil fuel dependent society, but we need reminders of how different our way of life is from so much of the world. Furthermore, by and large, my students are proud of their country. We say the pledge every day, and the adults in our community take pride in being American citizens. Seeing that the US produces more carbon by far than any other nation wasn’t something to take pride in.

“Why?”
“What can we do?”
“What about biodiesel?”

I answered with a brief explanation of the carbon cycle, in which I explained the difference between releasing long-stored carbon from fossil fuels and burning fuels whose production had involved the trapping of atmospheric carbon through the growth of plants.

Sara sits in the back row and had been quietly fighting a sneeze and listening to all the discussion and questions. As we were getting ready to leave she caught my eye, smiled wide and said “I’m going to plant a garden.”

When I return from the Arctic, I will ask my students whether THEY think An Inconvenient Truth is controversial and if so, why. I'm interested in what they think.

*Students' names have been changed.