I think that it's great to able to write such a piece by yourself and I would like to empower you to do it. So, firstly I will write a couple of points important when writing any kind of speech. After that, you will find some points for this particular topic. I hope you will enjoy my short tutorial :)
Let's do this, then:
I. When you're writing a speech you have to take care of a couple of points:
Remember about the style of your piece. You are talking to people! Keep your listeners engaged, ask questions you will then answer in the following sentences. Don't be to formal - it's ok to throw a joke in but don't go too far, once is more than enough, you still want to be seen as a professional, don't you?
Have the whole piece in mind, be sure that you know the goal of your speech. For example, do you want to convince somebody to use less fossil fuels in order to decrease the CO2 emission and therefore contribute to protecting the Ozone Layer? If yes, build up your arguments to reach this conclusion at the climax of your speech.
Think about your listeners and their motivation. If somebody is poor they will not be willing to switch to a different type of fuel because it's way more expensive. However, they might be happy to exchange their deodorants from sprays to cream for example.
Produce a chain of short points. Explain your point, show it's merits and challenges and then add it to the whole logical process that you are trying to build in order to reach your Goal, specified at the very beginning.
If you try and keep those points in mind you shouldn't have any problems writing a well organized speech :)
II. Points about the Ozone Layer Protection
Global warming danger - we are facing a situation when melting icebergs are making the ocean level rise higher and higher. Ecosystems around the world are not benefitting from this process and some habitats are destroyed.
It's bad for people. Sunburn can become a very common problem if the situation continues to unroll like it does now. We might even reach a point where it will not be possible for people to leave their homes without sunscreen on.
I believe that those points are the most important and what you need to do is to elaborate them more, give a couple of examples and build up to the point - Ozone Layer Deterioration is Endangering our Well-being.
I hope I helped,