I asked my students to tell me if they have observed any change in weather pattern lately. They said that there was less snow in the past few years. I asked them what do they think the cause was. All of them agreed that  pollution is the cause. I showed them a PPT and than talked about weather/climate, the four seasons and how the climate is changing due to human action. We watched some videos indicated in the course, we talked about their meanings, we tried to identify as many causes of climate change as we can. Finally, I asked  each of them to realize a small drawing representing the cause of climate change which he/she considered the most destructive. At the end, they all presented their own drawing and  pinned it on the wall of causes.