Chemistry Solutions

"The good thing about science is that it’s true whether or not you believe in it."

- Neil deGrasse Tyson

For the third year in a row, a new record was set for globally-averaged temperatures.¹ Figure 1 puts this in a broader context, showing the warming trend that has become more prominent over the last 30 years. And yet, despite these facts, according to a 2016 survey, only 70% of Americans think global warming is happening. ² What’s even less accepted are the causes of global warming; only 53% of Americans think that human activity is responsible, while 34% attribute warming to natural changes in the environment. Even more concerning is that only 11% of Americans know that there is a broad scientific consensus that human activity is the main cause of global warming and climate change.

Figure 1. Global Land and Ocean Temperature Anomalies, January - December. Temperature anomaly is relative to the average for the 20th century.

Source: NOAA National Centers for Environmental information, Climate at a Glance: Global Time Series, published March 2017, retrieved on April 12, 2017 from http://www.ncdc.noaa.gov/cag/

What further confounds the issue is how acceptance or non-acceptance of global warming has become closely correlated with political affinity, and this partisan divide is not just an American phenomenon. ³ However, framing global warming as a fundamentally scientific issue allows us to examine the science involved aside from the politics, and helps us ensure that global warming is more widely understood. Studying the science of global warming and climate change provides a context in which students can successfully learn and apply chemistry concepts while coming to understand what is arguably the most pressing global scientific issue of the 21st Century.

At a minimum, a basic understanding of the scientific principles of global warming and climate change includes a fundamental grasp of the main causes and measurable effects. Figure 2 gives a visual overview of the mechanisms leading to the effects that continue to be observed. These core concepts of global warming and climate change can be summarized as follows:

Figure 2. Cause and effects of global warming & climate change.

• Humans have been burning fossil fuels at an increasing rate since the 1850s.⁴
• Burning fossil fuels releases CO₂ into the atmosphere; levels of atmospheric CO₂ are higher than they have been in modern history and continue to increase.^5,6
• CO₂ and other greenhouse gases in the atmosphere trap the sun’s energy, similar to the insulating properties of a blanket. ⁵
• Global temperatures have been rising over the last 30 years, surpassing previously documented record temperatures.⁶
• Rising temperatures can be attributed to the increased presence of greenhouse gases in the atmosphere, specifically the unprecedented increase in CO₂. ^5,6
• Rising temperatures are leading to changes in many climates around the world, causing shifts in many natural systems including (but not limited to) extreme weather patterns, increased acidity in the ocean, and melting arctic sea ice.⁶
• Identifying human activity as the main cause of climate change is supported by 97% of scientists — what many refer to as the “scientific consensus” about human-caused global warming.⁷

Global Warming and Climate Change (GWCC) in Chemistry

At first glance, the basic climate topics listed above may seem daunting — and I’m not suggesting that it is only chemistry teachers who should bear the burden of teaching all of these concepts. What I am trying to convince chemistry teachers of is that we can do more: climate change is something that can and should be integrated into your chemistry curriculum — but you shouldn’t need major restructuring to incorporate it. We are in a prime position to demonstrate many of the concepts behind climate change by connecting them to core concepts already present in our chemistry curricula. Table 1 summarizes some of the GWCC topics and their possible related concepts from chemistry.

Table 1. Comparing GWCC and Chemistry Concepts

The National Center for Science Education (NCSE) outlines four fundamental best practices ⁸ for teaching about climate change (Figure 3). The attached lesson, Calculating Your Carbon Footprint, demonstrates how I attempt to teach one of the GWCC topics (burning fossil fuels) alongside related chemistry concepts, using some of these best practices. In the lesson, students apply their knowledge of writing and balancing chemical equations and stoichiometry calculations to estimate their own individual carbon footprint caused by the daily use of energy from fossil fuels.

Figure 3. NCSE recommendations for teaching climate change

Make it local

I find the most important practice is the first: make it local. One of the comments I hear most often from my students when we talk about GWCC is that it they aren’t noticing any effects in their own lives. Surveys also indicate one of the more common arguments supporting non-acceptance of GWCC science is that respondents are not personally experiencing or noticing impacts from GWCC. ^1,3 Having students analyze and evaluate local data gives some perspective of what and where changes are occurring, whether they have noticed them or not, and also provides a relatable context for students to make the chemistry concepts more relevant.

The challenge in this approach is that it requires some behind-the-scenes work to find and prepare data or information in a way that is accessible and efficient for students to use in their learning. There is a mountain of data that is freely accessible, but not all of it is relevant or easily analyzed by students. In the attached Carbon Footprint lesson, I found data freely available from the U.S. Department of Energy about how much of each energy source is consumed each year, but the data was given in BTUs — not exactly a common unit of measurement for chemistry! In preparing my lesson for students, I did some fairly basic calculations to convert the BTUs into kg of fuel, which is what students use to do their stoichiometry calculations.

Having a chemistry or GWCC concept in mind before you begin looking for data or information will make the search easier, as you will be able to narrow down your search and filter through what you find. Ideally, the more local the information is, the better. However, local information is not always as easily accessible. If you can’t find information about your city specifically, most states have resources that can provide state-level data and information. Even if only national data is available, helping students examine local impacts, however subtle and unnoticed, helps to place them in the center of climate change — and not see it as something only happening in Antarctica (and therefore perhaps less relevant).

As much as possible, I try to give information to the students with minimal interpretation. This allows them to draw their own conclusions, with some guidance to ensure they are understanding it (this is also great practice for ACT/SAT prep on analyzing and interpreting scientific data and information). For more ideas on where to find local and regional information, see the Teacher Notes section of the attached lesson, and the Other Resources section below.

Make it human

Climate science, like all other sciences, is a human endeavor. It is important for students to realize that there is historical context to the development of the field, driven by the work of countless individual scientists and organizations. One example is Charles Keeling’s case study, which follows one scientist’s story as he decided where to take his science career. Eventually, his path led him to develop tools and techniques for measuring atmospheric CO₂ levels, restart and run the Mauna Loa weather station where CO₂ levels are measured, and fight to keep the station alive to continue collecting data for more than 50 years. His life’s work is summarized in the infamous “hockey stick” graph of CO₂ levels (also known as the Keeling Curve), which is an essential piece of evidence for GWCC. Although I have not used the case study in its entirety, I have used parts of it to show students about the development of CO₂ data collection.

© Mizerek/Bigstock.com

Giving students a chance to look at the data collection as Keeling did is much more powerful and instructive than simply showing them the end result. It also gives them the opportunity to draw their own conclusions, and see how the science has unfolded over decades. It is a great way to help them better understand the processes and politics of science (especially government-run and -funded science) while also learning about essential climate data and how it is collected.

NCSE also recommends connecting with climate scientists in order to show the people behind the science. I recognize that this is an area of growth for me in general, not just on the topic of GWCC. The International Panel on Climate Change (IPCC), drawing its conclusions from the work of thousands of climate experts from across the globe, should not go unmentioned. Recognizing the scope of scientific consensus around the causes of GWCC is something that I hope to figure out how to include in the future. I know there are chemistry teachers out there who have developed these types of connections within their own classrooms, and I hope to build on their ideas to make this a bigger part of mine.

Make it pervasive

Another practice I use is to make GWCC a recurring theme that we revisit throughout the entire chemistry course, making it as pervasive as possible. As stated earlier, there are many connections that can be made between GWCC and chemistry. Exploring as many of these connections as we can not only gives a broader understanding, but also allows students to get more exposure to the wide variety of impacts that are occurring around the world. For example, as part of learning about materials and their life cycles, students explore the structure of modern materials and the environmental impact of creating, transporting, and disposing of materials. In the weather unit, students learn about pressure, temperature, and convection alongside learning about the impacts of extreme weather patterns. In the fuels unit, students learn about combustion reactions, balancing equations, and stoichiometry — while also talking about fossil fuels, alternative fuels, and the pros and cons of each. While chemistry is still the main focus, GWCC and its effects are interwoven as much as possible.

Make it hopeful

The practice of making GWCC science “hopeful” is one that I find is less about the pedagogy or content, and more about personal attitude. Call me an optimist, but it is hard to approach such an overwhelming and potentially catastrophic topic without at least a hint of hope that things will work out eventually. I can imagine that as students learn more about the daunting challenges of combating climate change, they might develop feelings of anxiety about the future, even more than they already have from planning their future after high school.

I don’t mean to suggest that having an artificially cheery disposition is the right approach, either. Discussing solutions to at least some of the GWCC effects, along with the benefits and limitations of those solutions, might help to mitigate some of our students’ anxiety. There is hope in the fact that many brilliant scientists are working to mitigate the changes that are already happening, and hope that the future scientists we are teaching will decide to carry that work forward.

Other Resources

In order to begin to integrate GWCC in your own chemistry class, you might feel like you need to know more about or review the science behind it. Perhaps you know and understand the evidence, but are looking for ideas about how to incorporate GWCC into your classroom. Here are a handful of resources to help you start to build climate topics into your chemistry curriculum:

• The American Chemical Society has a wonderful toolkit that dives deeply into the evidence and summarizes the main conclusions around anthropogenic climate change. Broken down into four main topics, each section of the toolkit gives an overview of the science and plenty of links to the scholarly research behind it. It also includes a “Narratives” section that answers some of the common climate questions and arguments.
• The Climate Literacy and Energy Awareness Network (CLEAN) has evidence and explanations for climate change basics, and includes suggestions for helping students understand the basics by bringing climate change into your classroom, with example activities, interactives, and lessons for middle school through college.
• The National Climate Assessment “offers a wealth of actionable science about the causes, effects, risks, and possible responses to human-caused climate change.” The resources that are provided are broken down by region, which is especially useful when looking for local or regional data and impacts of climate change.
• The National Oceanic and Atmospheric Administration’s Climate at a Glance web-based resource allows access to national temperature and precipitation data that can be customized for periods of time and locations within the U.S. It is one of the sites that I have found easiest to use to access to the data, both in graphical format and in tables.

Conclusion

The scientific evidence that underlies GWCC has many connections with common chemistry topics, offering opportunities for students to make connections and better understand the fundamental mechanisms. We have a responsibility as chemistry educators to do our part in teaching these fundamentals, and doing so does not have to detract from the chemistry that we are already teaching. Rather, including GWCC concepts is a way to give context to the importance of understanding chemistry, and can help students develop a better understanding of why chemistry truly is the central science.

The ideas presented here are by no means an exhaustive study of how GWCC can be integrated into chemistry curricula. Have you ever taught a chemistry lesson around climate change? How are you already integrating GWCC into your chemistry class? Have you thought about bringing in GWCC, but just aren’t sure where to start? I would love to see more thoughts or ideas in the comments, or start a conversation on the AACT discussion board.

References

1. https://www.nasa.gov/press-release/nasa-noaa-data-show-2016-warmest-year-on-record-globally 2/2/2017
2. http://climatechangecommunication.org/wp-content/uploads/2016/06/Climate-Change-American-Mind-March-2016-FINAL.compressed.pdf 1/4/2017
3. http://www.pewglobal.org/2015/11/05/global-concern-about-climate-change-broad-support-for-limiting-emissions/ 1/7/2017
4. https://www.eia.gov/todayinenergy/detail.php?id=10 3/16/2017
5. https://climate.nasa.gov/causes/ 3/15/2017
6. https://climate.nasa.gov/evidence/ 3/15/2017
7. http://iopscience.iop.org/1748-9326/8/2/024024 1/8/2017
   • Note that this statistic measures actively publishing scientists’ work, and the authors did not personally interview each one. A 2014 Pew Research poll surveyed AAAS scientists, and found 87% of those surveyed attributed global warming to human activity.
8. https://ncse.com/library-resource/teaching-climate-change-best-practices 12/22/2016