For over a decade, aspiring physicians and public health scientists have been sitting in bricks-and-mortar classrooms to take a Harvard course called “Human Health and Global Environmental Change.”

This semester, for the first time, students sitting in front of computer screens across the globe will have the chance to take the class free of charge.

The new online version of the class, PH278x: “Human Health and Global Environmental Change,” will be offered this spring through edX, the online education platform launched by Harvard and MIT last May.

PH278x is the second School of Public Health class to be offered through edX. Last fall, in the first semester of edX, PH207x: “Health in Numbers: Quantitative Methods in Clinical and Public Health Research” boasted an enrollment of over 50,000 students.

PH278x will be co-taught by Aaron S. Bernstein, pediatrics instructor at Harvard Medical School, and John D. Spengler, professor of environmental health and human habitation at the School of Public Health.

“The goal of the class is to help students understand that when we alter the planet’s climate or dramatically change the way life on the planet lives, those actions have direct effects on the ability of humans to lead healthy lives,” Bernstein said. “There is a tremendous knowledge gap around the world on these issues, and the opportunity to provide a free resource to people all over the world is immense.”

PH278x has branched beyond the scope of Harvard’s campus before. In the past, course lectures have been recorded and distributed to hundreds of students in other medical school and public health universities. But Bernstein said the leap to virtual education will present new challenges, including the difficult task of assessing whether students are actually learning online.

Bernstein said that PH278x, along with other non-quantitative courses offered through edX for the first time this semester, “will be real tests of pushing past what this platform is capable of.”

The PH278x team has been discussing the idea of filming footage outside the classroom to be used in the course. For example, to complement his discussion of the globalized food industry, Bernstein said he might take a camera to the grocery store to document the components of a meal.

“We’re thinking of the life cycle of each of those goods on a larger scale and what that means for sustainability for food consumption,” Bernstein said. “Using those real world experiences—something you wouldn’t be able to do in the classroom—can really bring those ideas home. EdX is a great vehicle to have that conversation with.”

—Staff writer Cynthia W. Shih can be reached at cshih@college.harvard.edu. Follow her on Twitter at @CShih7.