The link above is of a “time-lapsed” animation showing the level of arctic sea ice each year from 1990 to what it is projected to be in 2049. In a class discussion on climate change, I would show this animation to students and have them first analyze what trends they notice in the levels of arctic sea ice from 1990 to the present year and then discuss whether they agree with the projects for the next 38 years. The video plays pretty quickly, so I would slow it down or move frame-by-frame so that the students can really see the differences in the levels of the sea ice.
An additional activity that could be extrapolated from this resource is to have the students research why the levels of sea ice are so variable from year to year (and not necessarily always in a declining pattern). They could research weather/climate patterns for specific years and then use that information to support their predictions on what levels the sea ice will be at in the future.