David Suzuki’s website offers a free .pdf download (176 pages) for educators. You do have to hand over an email address, but the booklet is useful enough that it’s worth it. You can get the booklet here.
Teachers with higher-level classes can use many of the pages as is for vocabulary, reading, discussion and writing. Teachers with lower-level classes may have to adapt the activities and reading. As well, some of the activities just won’t work for online schools.
The students are being taught a lot of this information in school; they will probably be the generation to make the most environmental changes in China. A few of the older students are becoming quite passionate about the environment and enjoy heated discussions about one’s personal responsibility to the environment.
P.S. Occasionally, there is an issue with Mr. Suzuki’s heritage. I try to breeze over the matter by mentioning the multiculturalism of Canada. If that doesn’t work, I point out that his family has been here for many generations (Wikipedia complies by providing such information). This matter has only come up once or twice with older students, though.