Planet In Peril is a special website from CNN about environmental crises throughout the world.
It has a number of short video clips, though their speaking speed is probably too fast for English Language Learners (except for those who are advanced). However, the site has a lot of slideshows with simple captions, as well as other interactives, which would be accessible.
I’ve placed the link on my website under Toward The Twenty-First Century.
Thanks to Phyllis’ Favorites for the tip.