Alex Honnold and Hazel Findlay recently made two E6 big-wall first ascents in Greenland during a six-week expedition to the East of the country, where they combined climbing with climate science.

Alongside French glaciologist Heidi Sevestre, the team studied moulins, measured the density of the ice cap, sunk a NASA robot into a fjord, placed temperature sensors on the rock and drilled core samples from high on the walls to help climate scientists undergo a 'health check' of the area.

In order to reach the Renland Ice Cap, the team's first goal was to climb Pool Wall, near the fjord of Scoresbysund. They graded the line E6, but found it considerably tougher given the loose rock and harsh conditions. "It doesn't do justice to how mega the wall is. It was 20 degrees F (-6 degrees C), and we climbed it in a snowstorm." Alex Honnold told Nat Geo.

They completed the line over two days and worked with a rope access team to set up fixed ropes for climate scientists to jumar up while collecting rock samples en route. These samples will help scientists to reconstruct the glacial history of the area.

After dragging a radar device along the Renland Ice cap, Hazel and Alex arrived at the foot of their prize goal of the trip: a first ascent of the 1200m granite-gneiss tower, Ingmikortilaq (Ing-mik-or-tuh-lack). The pair climbed the northeast ridge and fixed ropes over 5 days to the halfway point, then climbed to the summit in a two-day push.

The three-million-year-old gneiss was extremely loose due to weathering and the freeze-thaw cycle. Hazel told Nat Geo that it was "definitely more of a psychological challenge than physical."

"We literally went off the edge of the map to reach this wall," Honnold told Nat Geo from base camp. "It is definitely one of the biggest first ascents I've ever done–and one of the most stressful due to how dangerous the climbing was." 

To return to civilisation, a 20-hour motorboat journey to the nearest Inuit village awaited the pair after completing the route.

The team used a total of 15 different research techniques during this expedition to perform a 'health check' in an area of Greenland that has remained unexplored

Lead climate scientist Heidi Sevestre told National Geographic: "We desperately need scientific data from this region. Studying the fjords, the glaciers, the ice sheets, will bring so much data to the scientific community that the contribution will be extremely positive."

The expedition was filmed for National Geographic's Disney+ series On the Edge with Alex Honnold.