From the Jewish Climate Network:

We are asking our community to place an ice block beside the Seder plate and open up a conversation about climate change this year (2022), while linking it to the fundamental themes of Pesach.

The ice block represents the rapidly melting ice caps and sheets throughout the world caused by human activity. As the ice block shvitzes on our Seder table, we are reminded that time is running out for action. It becomes a physical prompt to ask questions, much like the other Seder table objects prompt questions.

To support these questions, the JCN has created a printable Ice Block Challenge guide that can be incorporated into Seder night.