USGS (US GEOLOGICAL SURVEY)--is a science organization that offers information the health of the planet. It studies ecosystems, watches out for natural disasters that may affect us, monitors natural resources, and watches the impacts of climate and land-use change. It was created in 1879 and is still alive and continues to be an instrumental in keeping our planet and its inhabitants safe and informed.
The site's EDUCATION section is a treasure trove of resources, videos, pamphlets, lessons, maps on every corner of the planet (and beyond in some sections). For grades 8 and up, there are free lectures on natural phenomena. Each is about 50 minutes on average. Here is another link for the older students on LAND AND PEOPLE (Cape Cod, Everglades, Los Angeles). This site also has a student book as well as the teacher resource one as downloads. For grades K-7 USGKIDS, there are coloring books, stories, games, and fun projects. US CORAL REEFS Again, it is all free.
This type of exploration might inspire some of your students to enter careers that protect the planet:)
ELL TEACHER PROS