We also noticed that cattail plants were everywhere. They didn't used to be here. Maybe the cattails took over the pond and sucked up all the water. Scientists try to come up with as many explanations as possible. Could we think of any other explanation? When it didn't snow the whole month of December, we started to wonder if the pond had simply dried up. It had been unusually warm for Utah. Maybe we were experiencing a drought. Maybe all the pond water had simply evaporated.
The following week, I invited students to do some research on Earth's past. Students worked in small groups to review a brief text, each text describing a different period of geologic time. Individuals were to select a sentence, phrase, and word that they felt captured a big idea or an important feature of this time period. Then, they were to discuss their choices with the group and try to come up with a consensus.
I really like this thinking routine because it helps students capture the essence of a text, gives a structure to the students' discussion, and asks students to explain and justify their choices. And, it's amazing how well a single word can represent a whole text. Words are powerful!
Students were surprised to discover that humans were such a recent addition to the planet, appearing only 200,000 years ago (placed at the very tip of our 45 ft. long string). Note that each foot of string represented 100 million years. We followed up this activity by watching a documentary on Earth's history (Cosmos: A SpaceTime Odyssey, Episode 9, "The Lost Worlds of Planet Earth"). The students LOVED this documentary.
The following week I asked students: Do you think that the earth is still changing today? Will Earth continue to change in the future? In what ways? It was now January. President Obama had just given his state of the union address. I decided to show students a clip. I asked students to listen for what the President called "the greatest threat" to their generation. President Obama said, "No challenge poses a greater threat to future generations than climate change."
"The climate scientists said that this warming trend — temperatures going up over a long period of time — could only be explained if you looked at human activity. They blamed burning fossil fuels. Burning fossil fuels, such as coal, release greenhouse gases into the Earth’s atmosphere. These greenhouse gases help to trap in heat."
I enlisted the help of our grade 4 students who were studying weather. They helped us analyze Utah weather data for winter 2015 and compare it to weather data from last year at this time. They also compared this data to the average Utah temperature in winter. What we found was a pattern. It did, in fact, seem to be getting warmer.
We looked for more evidence of climate change on NASA's website (see graph below). We learned that both current and past levels of atmospheric carbon are measurable. Climate scientists have drilled deep into Antarctic ice to analyze the trapped ancient air. What they discovered was that current levels of atmospheric carbon are off the charts. Earth has a fever.
To better understand how carbon emissions could cause global warming, we watched a documentary on climate change (Cosmos: A Spacetime Odyssey, Episode 12, "The World Set Free"). This documentary got a pretty big reaction from students. They had some strong feelings and concerns.
I invited students to discuss in small groups the evidence for climate change, and then write a headline for their own news article. I explained that the headline should summarize or capture a key idea that they felt was important for the public to understand. Because while expert climate scientists agree that climate change is happening, not everyone in the general public is aware of this.
When we looked collectively at the headlines, it was clear that students were hopeful. They believed they had the power to make a difference, and they wanted to take action. But where should we start?
Our school is an environmental science magnet school and is one of the few green schools in Utah. So students were pretty confident that our energy came from our solar panels on the roof, and the wind turbine in the back of our school yard. But I was skeptical. I suggested we invite the district energy specialist, Mr. Smith, to visit our classroom. It's his job to help the schools in our district reduce energy use (and thereby save money). I was certain he would have answers for us.
It turns out our school gets its power from the Rocky Mountain Power Company. And, they mostly get the energy from burning coal (i.e., fossil fuels). Our school alone put 278 metric tons of carbon (CO2) into the atmosphere in the year 2014. Mr. Smith gave us some good information about how we could conserve energy at school and at home. His presentation was very informative. We were grateful for all that he taught us.
I challenged students to engineer turbine blades using found materials. Their goal was to harness the power of the wind and generate at least 100 volts of electricity (about the amount needed to power a light bulb). We discussed the different variables students would need to consider: number, size, and angle of the blades, materials used to construct the blades, and how they would attach the blades to the hub (a cork). Students worked in small groups to make a plan and sketch a design, including a materials list. Then students collected items from the "store" and started building.
I loved listening to students' conversations. Some groups built big blades then switched to smaller blades and got better results. Others built turbines with four blades then switched to three blades. Angles were adjusted, different materials were investigated. Some blades fell off and the challenge became how to keep the securely attached to the cork, also reducing wobble. In the end, the winning design was built by a team of three girls. Their turbine generated over 300 volts of electricity!
Now, onward to making solar panels! And students have been working hard on campaign posters for Earth Week in April. They are hoping to raise awareness about climate change, and what we can all do to help. I'm very proud of my grade 5 students. They are problem-solvers. We have calculated our own carbon footprint (pdf version), and set goals to reduce our carbon emissions at home and at school.
Just after my students completed this climate change project, I attended an NSTA conference in Chicago and got to meet a climate scientist and engineer. I was so excited.
It was a great success story that demonstrated how scientists and engineers collaborate to find answers and solve problems. I even got to touch the ice core sample you see here, and look closely at the tiny air bubbles trapped inside. It was so cool! (No pun intended.) Even better than getting to meet Bill Nye...almost. Science rules!
Now if I can just find an environmental engineer who can help us solve the mystery of our disappearing pond water. Is erosion, the cattails, or global warming to blame? Stay tuned.