Alaska’s top-heavy glaciers are approaching an irreversible tipping point

The melting of one of North America’s largest icefields has accelerated and could soon reach an irreversible tipping point. That’s the conclusion of new research colleagues and I have published on the Juneau Icefield, which straddles the Alaska-Canada border near the Alaskan capital of Juneau.

In the summer of 2022, I skied across the flat, smooth and white plateau of the icefield, accompanied by other researchers...