ES 10 Students Take on Climate Change Skeptics

Natural forcings do not account for observed 20th century warming after 1970. (Source: Meehl et al., 2004: J. Climate)

Four years ago, as a freshman at Stanford, I took a class that forever changed my life. While biking across campus, I was struck by one poster that stood out amidst the advertisements for tutoring opportunities and theatrical auditions—it was the class poster for Earth Systems 10: Introduction to Earth Systems. Underneath a Venn diagram depicting the intersection of natural system and humans systems, Earth Systems 10 proclaimed it was “not yet a requirement for Stanford, [but] already a requirement for life.”

In the first lecture given annually in ES10, Associate Director of Earth Systems, Julie Kennedy, asks students, “Why Study Earth Systems?” Kennedy insists that students should feel a compulsion to know something about the world around them and a desire to gain the knowledge necessary today to be a part of tomorrow’s solution for a healthier planet. Earth Systems 10, Kennedy argues, is the first step down such a path to environmental activism.

Inspired by Kennedy’s words, I enrolled in Earth Systems 10 and four years later, I find myself an Earth Systems major and a member of the teaching assistant team responsible for organizing this interdisciplinary course, which spans subjects as wide-ranging as geology, ecology, oceanography, economics, policy, and education. This year, 22 Stanford faculty members delivered 30 lectures for the course, which were dissected and connected in weekly discussion sections taught by the TAs.

The students in ES10—this year, 185 enrolled—are as wide-ranging as the course material. Though primarily an introductory course aimed at underclassmen pursuing future environmental studies, ES10 attracts a broad student base of juniors, seniors, and coterms seeking a disciplinary breadth graduation requirement in natural sciences or simply a unique class.

ES10 teaches students to critique scientific articles about environmental issues and articulate their knowledge of the earth system to the less-informed. In keeping with this aim, ES10 students engage in a case study town hall debate concerning an environmental issue—this year, the future of the Sacramento Delta—and, in discussion section, practice answering difficult questions from potential global warming skeptics. While much of the layman world still debates the reality of human-induced global warming, the scientific community treats it as unquestionable fact. And, like scientists, says Head TA Jess McNally, in ES10 “We don’t debate climate change; it is just something we teach.”

In November, The Stanford Review published Matt Cook and Dakin Sloss’s op-ed, “The Man-Made Myth,” which attacked the veracity of anthropogenic climate change. Seeking to test my students’ abilities to educate their own peers about climate change, I wrote a final exam question asking them to refute the article. On the ES10 final, students were presented with four quotations from “The Man Made Myth” and asked to rebut three of the four statements. The results were inspiring. The time-pressured writings of introductory-level Earth Systems students rivaled Brett Dietz’s full-length rebuttal in the Review, “The Myth of Controversy.”

Students were first asked to rebut Cook and Sloss’s claim that paleoclimatic trends showing global temperature increases preceding CO₂ rises “invalidate anthropogenic climate change theory.” One ES10 sophomore correctly explained that, “CO₂ does not cause changes in temperature but amplifies warming trends.” Illustrating the concept of radiative forcing, she explained that carbon dioxide exacerbates solar radiation and intensifies warming of the planet beyond natural levels. Another ES10 student further explicated this idea, writing that, “CO₂ is a source of positive feedback…as the system warms, CO₂ levels rise, trapping more solar radiation, which, in turn, increases the system’s warming.”

Next, students commented on the accuracy of computer models of future climate trends. A junior in the class asserted that, contrary to the claims of Cook and Sloss, “today’s models are ever improving, and the predictions are matching temperatures very well.” She further described how “the only models that match well for the second half of the 20^th century are those which take into account both natural and anthropogenic greenhouse gases.” Illustrating the same point, another ES10 student drew a graph depicting temperature models based on natural and natural + anthropogenic CO₂ sources (see figure); current warming trends can only be explained by anthropogenic greenhouse gases.

After computer models, ES10 students addressed the skeptic claim that current temperature rise is attributable to natural variability. One student explained that while “natural climate cycles have frequently occurred…temperature increase since 1850 [the start of the Industrial Revolution] has been much more rapid than in the past.” This student was right in realizing that the unprecedented rates of temperature  increase are what make today’s warming patterns so worrisome. While the planet’s temperatures have been higher than today (over 50 million years ago), temperatures and CO₂ levels have never changed so quickly.

“The Man Made Myth” concludes that since “science proves human carbon dioxide emissions are not responsible for global warming…it is preposterous for us students to alter our lifestyles or sacrifice the wonderful benefits of technologies that rely on fossil fuels.”  ES10 students derided this assertion that science “proves” a lack of human responsibility and acknowledged that, “even if there was no global warming, that does not mean it is okay to overexploit non-renewable resources.” One ES10 senior described the negative economic and political consequences of fossil fuel usage. A freshman highlighted the Stanford Green Living Council as an example of ways in which students alter lifestyles without “sacrificing” modern conveniences. One eloquent sophomore argued that, “every individual decision to reduce fossil fuel consumption helps. Yeah, you’re a ‘drop in the bucket,’ but what is water made of, but a bunch of drops?”

Environmental education is a field dedicated to changing human behavior. As McNally says, “ES10 is environmental ed, and so, it should result in a change of behaviors.” Student responses on the Earth Systems 10 final exam suggest that the class might be doing just that. So next fall, when you’re shopping for classes, whether you’re a sophomore searching for a major or a senior simply trying to graduate, consider taking ES10. It just might change your life.

Cara Brook, a senior majoring in Earth Systems, was a teaching assistant for Earth Systems 10: Introduction to Earth Systems during fall quarter.