Landslides. Wildfires. Hurricanes. Floods. Natural disasters are becoming more frequent and disruptive, and as they increase, so does the attention being paid to the fragility of natural systems and the loss of biodiversity.

Today, more than 350 matriculated students and approximately 1,800 open-enrollment students are studying in the Harvard Extension School Sustainability Program — an increase of approximately fivefold over a decade ago.

The Harvard T.H, Chan School of Public Health’s John Spengler, the Akira Yamaguchi Professor of Environmental Health and Human Habitation and one of the program’s co-founders, has seen the program blossom from a few online courses in the mid-1990s. Interest in sustainability “kept building, eventually becoming an important mantra that began to attract people,” he said. “We first called it the Sustainable Environmental Management Program, which morphed into today’s Sustainability Program.”

According to Megan Epler Wood, an instructor at the Extension School and director of the Chan School’s International Sustainable Tourism Initiative, “The growth of the tourism economy is creating stresses on local destinations and their nonrenewable resources. … The rapid growth of aviation is driving greenhouse gas emissions, heightening the need for sustainable tourism.”

Today companies in nearly every industry are taking a closer look at their sustainability practices. “Organizations are increasingly charged with modifying business practices to protect the planet’s finite resources,” said Thomas P. Gloria, director of the Sustainability Program. “As a result, we’re seeing companies taking more responsibility for what they make and sell, along with growing global concerns around issues of human health and the environment. This program is a reflection of where the job market is headed.”

Tackling the challenges

The Sustainability Program offers a master’s degree track as well as a choice of five graduate certificates ranging from corporate sustainability and environmental policy to green building and natural resource management. The flexible, world-class distance model offers more than 120 courses, including Epler Wood’s “Environmental Management of International Tourism Development,” “Ecotourism and Sustainable Development,” and “Sustainable Tourism, Regional Planning, and Geodesign.”

Yehia F. Khalil, a professor at Yale University and an alumnus of the Sustainability Program, said it offers “science-based knowledge about sustainable development, the social responsibility of organizations to protect the environment, and ways in which we can protect our ecosystem from the unintended consequences of products that are not designed for the environment.”