Hi Eric,
Thanks for your post, and welcome to the course!
You have given considerable thought to running this activity and touching on important points, including ensuring learners have a solid grasp of what greenhouse gases mean. This will be new vocabulary for many, and a poster featuring new STEM terms will help the learners remember this over time.
It is an excellent opportunity to present ideas on how to reduce impact in the area but also see what is already underway-there are a lot of positive changes, and this is important to highlight in terms of our rapidly changing energy supply here in Ireland, more cycle lanes, solar-powered homes, etc.
You make a good point about games; they are a great motivator when learning! One option could be to make it a race to see who can retrieve a certain climate scenario first, etc., to add a competitive element once everyone is confident in using the tools.