im trying to be more positive *sheds electrons and becomes highly unstable*
About a year ago, for my summer biology class, I had the same guidelines for a powerpoint as well. I ended up doing my powerpoint on waste management, whether industrial, residential, etc. I went over the techniques of waste management we currently use, such as landfills, incineration, recycling and compost, stating the benefits and drawbacks of each.
That topic was particularly interesting for me for some reason, but another great topic that was addressed in my class was overfishing. Since we lived in an area where overfishing is seen all too often, she focused on our area and it had a huge impact on the entire class due to that context. I wish I had thought of something like that, though I was very pleased with mine. So covering an issue relevant to your particular area could be a great option as well!