I've been watching a lot of nature documentaries lately. I like how you can either pay super close attention to them, or use them as background TV. I was a massive fan of the original Blue Planet, so it's been cool watching the Blue Planet II episodes drop recently, as one example. A typical nature documentary will always have a little look how bad we're screwing up the environment twist, which is the perfect time and place for such a message.
Speaking of perfect time and place, why not remind ourselves of all the endangered animals out there with placeholder images! That's what Endangered Species Placeholders is. It's like PlaceKitten, but for environmental good.