Of all the things that have come up during this election cycle — from immigration to the size of one candidates' hands — one issue that didn't get much air time was climate change.

"We tend to be very focused on the short term," explains George Marshall, Director of Projects at Climate Outreach and author of Don't Even Think About It: Why Our Brains Are Wired to Ignore Climate Change. "We tend to discount [...] things happening in the future the further away they are."

In this week's encore episode, Shankar Vedantam takes us to the Mendenhall Glacier in Alaska to explore why it's so difficult for us to wrap our heads around climate change.

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