Since January, explorer Eric Larsen has reached the North and South Poles and the summit of Mount Everest -- marking the first time somebody has accomplished all three in a single year.
Larsen, who summited Everest on Oct. 14, tells NPR's Melissa Block it's a relief to be done.
"I'm actually quite tired," he says from Kathmandu, Nepal. "I've been going constantly for the past month and a half."
Larsen, 39, called it his tour of the "top, bottom and roof of the world." And he's using the adventure to boost awareness of climate change.
"I really like being outside. I love camping, I love winter," he says. "And as someone who has been outside and kind of traveled to some of the more remote places on the planet, I've started to see some of the changes due to climate change firsthand, and I wanted to tell the story of what I call the last great frozen places on the planet."
Larsen acknowledges that travel for the expedition itself contributed to his carbon footprint, but he said getting the message out was important.
"The problem of climate change is something that needs bold action, and I felt that this expedition was a bold step forward to get people's attention and hopefully make a bigger difference," he says.
Larsen says there were visible signs of climate change on all three legs of his expedition.
"In Antarctica, we witnessed nearly two weeks of little or no katabatic winds, which are really important in terms of emptying cool air out of Antarctica," he says. "In the Arctic, thin ice, open water. On the way to the summit of Everest, looking out across the valley, seeing evidence not of where glaciers are, but where they had been."
As he climbed Mount Everest, Larsen says he had one of the most stunning views of the night sky.
"It was surreal, because looking out across the horizon, it was actually like we were looking down at many of the stars along the perimeter," he says. "That was an incredible experience for sure."
But now, Larsen's idea of a vacation is a "warm beach, an ocean where I don't have to wear three layers of underwear."