CEZANNE TO CLIMATE: ART AS SOCIAL MATH FOR UNDERSTANDING GLOBAL CHANGE

Social math is a method to make meaning from complex data, typically used in outreach to a general audience. Unfamiliar concepts or processes are compared to familiar examples in order to tell a story that is as compelling to non-technical learners as the data themselves are to a technical audience. In the Earth sciences important processes are often too fast or too slow to be directly observed, or too big, too small, or too far away to be part of the lived experience of most people. When the subject is climate change the challenge is even greater, as foundational climate concepts like greenhouse gases and infrared energy are both invisible.

During the development of a classroom experiment on the selective absorption of infrared energy by carbon dioxide gas we sought to familiarize learners with this concept through the use of social math. After considering several colorful examples from fashion and pop culture, it seemed appropriate to begin with the work of the 19th century artists whose innovative techniques allowed them to actually paint light. Impressionist painters placed light at the center of their work, seeking to show us both its brilliance and iridescence as well as its absence in the shadows cast by the objects in the scene. Cézanne, Monet and Renoir introduce us to the concepts of color, wavelength and selective reflectance and absorption.

The classroom experiment is designed to show selective absorption, first at visible wavelengths using an inexpensive light meter to display the transmission of light through colored liquids. This experiment is followed by similarly-designed experiment with infrared light. The infrared experiment is more abstract than the visible experiment both because everything is invisible, and also because the tools available to observe absorption are themselves a little more abstract. A hand-held infrared thermometer is repurposed to record IR absorption. In so doing, this is one of the few experiments in the canon of student greenhouse effect activities to actually measure the absorption of energy by carbon dioxide.