user: Without quoting directly from the text, give me a rundown of the greatest risks from attempting to climb K2.

Input:
K2, at 8,611 metres (28,251 ft) above sea level, is the second-highest mountain on Earth, after Mount Everest (at 8,849 metres (29,032 ft)). It lies in the Karakoram range, partially in the Gilgit-Baltistan region of Pakistan-administered Kashmir and partially in a China-administered territory Trans-Karakoram Tract included in the Taxkorgan Tajik Autonomous County of Xinjiang.

K2 also became popularly known as the Savage Mountain after George Bell—a climber on the 1953 American expedition—told reporters, "It's a savage mountain that tries to kill you." Of the five highest mountains in the world, K2 is the deadliest; approximately one person dies on the mountain for every four who reach the summit. Also occasionally known as Mount Godwin-Austen, other nicknames for K2 are The King of Mountains and The Mountaineers' Mountain, as well as The Mountain of Mountains after prominent Italian climber Reinhold Messner titled his book about K2 the same.

The summit was reached for the first time by the Italian climbers Lino Lacedelli and Achille Compagnoni, on the 1954 Italian expedition led by Ardito Desio. In January 2021, K2 became the final eight-thousander to be summited in the winter; the mountaineering feat was accomplished by a team of Nepalese climbers, led by Nirmal Purja and Mingma Gyalje Sherpa.

K2 is the only 8,000+ metres (26,000+ ft) peak that has never been climbed from its eastern face. Ascents have almost always been made in July and August, which are typically the warmest times of the year; K2's more northern location makes it more susceptible to inclement and colder weather. The peak has now been climbed by almost all of its ridges. Although the summit of Everest is at a higher altitude, K2 is a more difficult and dangerous climb, due in part to its more inclement weather. As of February 2021, only 377 people have completed the ascent to its summit. There have been 91 deaths during attempted climbs.

There are a number of routes on K2, of somewhat different character, but they all share some key difficulties, the first being the extremely high altitude and resulting lack of oxygen: there is only one-third as much oxygen available to a climber on the summit of K2 as there is at sea level. The second is the propensity of the mountain to experience extreme storms of several days duration, which have resulted in many of the deaths on the peak. The third is the steep, exposed, and committing nature of all routes on the mountain, which makes retreat more difficult, especially during a storm. Despite many attempts the first successful winter ascents occurred only in 2021. All major climbing routes lie on the Pakistani side.[citation needed] The base camp is also located on the Pakistani side.

assistant: Although not as well-known as Mount Everest, K2 is the second highest mountain on earth and is arguably the most dangerous to climb.  In addition to the lack of oxygen experienced at such high altitudes, all routes to summit K2 are steep with significant exposure.  This exposure, combined with the mountain's propensity to experience extreme storms lasting for days, make for a deadly combination.  The extreme terrain and unpredictable weather leave little to no margin for error.