International students are welcome to take the Environmental Studies Certificate, however, all four courses are in the online format. Since international students must take at least 12 units (typically 3 courses) every quarter to maintain F-1 Visa requirements of which only one can be online, it is recommended that international students complete the Sustainability Certificate and Environmental Studies Certificate simultaneously, since Sustainability courses can be taken on-ground or online.
The Sustainability Certificate is comprised of 5 courses, while the Environmental Studies Certificate is comprised of 4 courses. Together, that is 9 courses: completing three courses each quarter for a total of three quarters fulfills the visa requirements and will earn you two certificates in very related fields. This is a recommended schedule for American students as well.