The catchy title on YouTube is The Most IMPORTANT Video You'll Ever See. The title in the video itself is Arithmetic, Population, and Energy. Regardless of what you think of the catchy title the video makes a powerful point.
Dr. Albert Bartlett from the University of Colorado at Boulder sits behind a desk, shows some slides and charts, and will probably scare the heck out of you. If you don't have a handle on the idea of exponential growth or compound interest this will be an eye opener.
The video is in 8 parts. Here are the links - part 1, part 2, part 3, part 4, part 5, part 6, part 7, part 8.
I'm not sure it's the most IMPORTANT video but I'd recommend it even if you aren't fluent in math. It will make you think a bit about our future.