When Deborah Hughes Hallett chooses examples to illustrate curricular concepts, she targets the intersection of the mathematics and her students' interests in issues of real-world importance. The University of Arizona and Harvard Kennedy School professor is currently looking to exchange the standard tank problems familiar from differential equations for an exercise related to methane sources and sinks.

Identify and craft a lesson around a naturally occurring mathematical structure, Hughes Hallett explained to fellow participants in MAA Professional Enhancement Program's "Math for a Sustainable Future" workshop, and "you end up…teaching people about sustainability in a way they might not have known."

Workshop co-organizer Debra Rowe of the Disciplinary Associations Network for Sustainability could not have been happier with Hughes Hallett's articulation of the math-sustainability connection. "I wish I could have YouTubed you on that," she said.

For three days in mid-March the MAA Carriage House played host to 25 mathematicians, scientists, and sustainability experts who traveled from around the country to collaboratively develop educational modules linking mathematics and sustainability. The "Math for a Sustainable Future" workshop marked the beginning of the mathematics community's contribution to the broader "Sustainability Improves Student Learning (SISL) in STEM" initiative, which unites professional societies in an effort to prepare students for the environmental challenges to come.

Workshop attendees face challenges of their own, of course. Hurricane Sandy forced a more than four-month postponement of the event, for one thing. And many of the workshop's invited participants operate as lone sustainability advocates in departments leery of uttering the s-word in the mathematics classroom.

John Roe (Pennsylvania State University) recalled the reaction to his idea for a general education math and sustainability course. Some of his colleagues said, more or less, "'We think you're crazy but you were department chair for six years so you've earned the right.'"

Such factors as the divisiveness of the climate change issue, already crowded collegiate syllabi, and the perception of math as an "amoral" discipline all contribute to the pushback sometimes encountered by those keen to mobilize math in the fight for a just and livable future. Organizers stress, however, that accomplishment of the workshop's objective—situating mathematics activities in authentic sustainability-related contexts—would neither expand curricula nor transform math into moralizing.

The online library of activities seeded by workshop participants will help legitimize sustainability efforts, Debra Rowe believes. She predicts that educators' arguments will be bolstered by the existence of "an official math site that's saying 'it's okay to teach math and sustainability; in fact, it's smart.'"

Though much work remains to be done, workshoppers made a solid start during their time together at the Carriage House. They uploaded to the SISL site drafts of more than 30 learning activities, covering a range of sustainability topics at levels appropriate for courses from developmental math through calculus.

By the end of the workshop there were modules-in-progress on energy savings from insulation, ocean acidification, the true cost of burning fossil fuels, selection of efficient appliances, and declining monarch butterfly populations.

Inspired by the solar array atop the library at Eastern Mennonite University where he teaches, Owen Byer worked on a lesson in which students use t-tests and ANOVAs to determine whether there is a statistically significant difference between the power outputs of individual solar panels.

Byer's EMU colleague Deirdre Smeltzer wondered aloud whether summing energy production across panels in an array could serve as a "real-life Riemann sum multivariable example."

Byer and Smeltzer work together at an institution with an established emphasis on sustainability, but, for many participants, "Math for a Sustainable Future" provided an unprecedented opportunity to connect with collaborators. Deborah Hughes Hallett spoke during the workshop wrap-up about the value of interacting with biologists and geologists such as Dan Abel and Bob McConnell, and many conversations that started over Carriage House tables—about delta subsidence and the Bakken oil and strategies for student engagement—will doubtless carry on via email.

Workshoppers will continue to develop math and sustainability learning materials, and others are invited to submit lesson plans as well. With a sustainability-themed Mathematics Awareness Month (April 2013) situated within a year dedicated to the Mathematics of Planet Earth, the time is ripe for the incorporation of sustainability topics into mathematics curricula.

In addition to contributing to the SISL site and working to get sustainability-related vignettes inserted into top-selling textbooks, many workshop participants expressed an interest in developing a math and sustainability MOOC (massive open online course). Marty Walter, mathematics professor (University of Colorado Boulder) and organic farmer, put it the most colorfully: "I think this is absolutely urgent. I think it's the most important thing I should be doing besides growing organic peaches."

Though the MOOC might take a bit longer, "Math for a Sustainable Future" co-organizers Ben Galluzzo (Shippensburg University) and Helena LeRoux (SUNY Sullivan) expect an initial set of materials to be available to the public from the SISL site by Earth Day 2013. —*Katharine Merow*