I am reminded of my expedition there — and of the repercussions that the loss of ice shelves will have around the world in the form of rising seas and accelerated climate change.

By Will Steger

February 20, 2017 at 11:13PM

The Trans-Antarctica Expedition, led by Minnesotan Will Steger, made its way through blowing snow as the six-man team neared the South Pole in 1989. (Associated Press/The Minnesota Star Tribune)

There is no way to comprehend the massiveness of the disintegration of Antarctica's Larsen C Ice Shelf unless you have skied and walked across it. In early winter 1989, as I set out across it on the International Trans-Antarctica Expedition, it would take us 31 days to cross the full length. Every day, camp after camp, through storm, whiteouts and clear weather, we skied and pushed our sleds, becoming intimately familiar with the ice shelf.

More recently, learning of the growing rift in the Larsen C ice shelf — a crack in the shelf grew by 17 miles in two months, the New York Times reported in an interactive feature on Feb. 7 — I am transported back to my time on the ice. I wrote then: "It is Antarctica, which I am seeing for the first time today, that is going to be the main player in the destiny of the human race. It is this snow and ice. If the atmosphere continues to warm, this ice right in this area is going to break off into the ocean." As I think about the impending breakup of the Larsen C, I am reminded again of the repercussions that the loss of ice shelves will have around the world in the form of rising seas and accelerated climate change.

What makes these ice shelves so important? Primarily it is their role in stabilizing what is behind them — the vast glaciers that feed them. If icebergs calve off an ice sheet too quickly, it can destabilize the whole system, leading the glaciers to speed their flow and adding more icebergs to the ocean. Eventually, fueled by warming seas, this process could melt the entire West Antarctic Ice Sheet, raising sea levels by 10 to 13 feet. While it's hard to tie individual events like the crack in the Larsen C to climate change, many studies and observations have documented the big-picture changes that climate change is influencing in the region. And with the continued warming in Antarctica comes the real possibility that the Larsen C shelf could totally collapse, joining its neighbors the Larsen A and B shelves.

I have seen this imperiled Antarctic ice sheet. The legacy of such an eyewitness experience brings with it a powerful call to action. And in fact, when news of the Larsen B ice shelf collapse reached me in 2002, I was motivated to dedicate the rest of my life to education and action around climate change, establishing Climate Generation: A Will Steger Legacy (then the Will Steger Foundation) in 2006 to advance this mission.

Now, news of another impending ice sheet collapse is in front of us. For me, this news represents the latest climate change wake-up call. How will we respond? We must all acknowledge that the climate and the geographies we are familiar with are changing, and we must assume a collective responsibility to rise to the challenge of restabilizing the system. Just as my international team members and I worked together to survive on our seven-month expedition, collective action and working across boundaries is the key to advancing climate-change solutions and building the clean-energy economy. While it might be too late for the Larsen C ice shelf, it is not too late to preserve a livable planet if we all come together in this moment. Our environment is sending us a message in the most forceful way it can. It's time to act.

Will Steger is a polar explorer and founder of Climate Generation: A Will Steger Legacy.