Mount Everest summit success rates double, death rate stays the same
over last 30 years

Date:
August 26, 2020
Source:
University of Washington
Summary:
A new study finds that the success rate of summiting Mount Everest
has doubled in the last three decades, even though the number of
climbers has greatly increased, crowding the narrow route through
the dangerous 'death zone' near the summit. However, the death
rate for climbers has hovered unchanged at around 1% since 1990.



FULL STORY ==========================================================================
As the world's tallest peak, Mount Everest draws more than 500 climbers
each spring to attempt the summit during a small window of favorable
conditions on the rugged Himalayan mountain that tops out at just over
29,000 feet.


==========================================================================
A new study led by researchers at the University of Washington and the University of California, Davis, finds that the success rate of summiting
Mount Everest has doubled in the last three decades, even though the
number of climbers has greatly increased, crowding the narrow route
through the dangerous "death zone" near the summit. However, the death
rate for climbers has hovered unchanged at around 1% since 1990.

The findings were published Aug. 26 in the open-access journal PLOS
ONE. They represent the most comprehensive look at success and death
rates in the published literature on Everest. The paper also identifies patterns in the characteristics of mountaineers -- such as age, sex and
prior experience - - that might influence their likelihood of summiting
or dying during the spring climbing season.

"Mount Everest is still a very dangerous mountain, and climbing it will
never become a walk in the park, because it's way above the limits of
what most people can do," said lead author Raymond Huey, a UW professor emeritus of biology. "Unfortunately, reported statistics of risk on
Everest are often inaccurate. By analyzing climbing data, we provide
accurate information on the chances of success and on the chances of
dying, thereby helping climbers make an informed decision about whether
to attempt this great peak." These patterns also can help Nepal and
China in deciding whether to institute restrictions on climbers such as
maximum age or experience level, Huey added.

Huey and colleagues analyzed the success and death rates for all
first-time climbers who had a permit to summit Everest during the period
of 2006 to 2019.

Previously, they applied the same statistical methods to climbers during
the period of 1990 to 2005 and, as a result, they were able to compare
success and death rates between the two periods.



========================================================================== During 1990 to 2005, more than 2,200 first-time climbers attempted
to summit Everest. During 2006 to 2019, that number increased to more
than 3,600 climbers. Importantly, the researchers focused on climbers
with paid permits, excluding climbers with additional tasks -- such as high-altitude porters, photographers and support staff -- along with
climbers who attempted to summit in other seasons, or who were attempting
the summit for the second time or more.

They also excluded a handful of years from the analyses when extreme
events such as ice fall avalanches or earthquakes led to cancellations
of the climbing season.

Comparisons between the two periods show that:
* Summit success rates from the first period to the second period have
essentially doubled; two-thirds of climbers now reach the summit,
verses one-third previously
* The overall death rate of around 1% hasn't changed * A contemporary
60-year-old climber has the same success rate (about 40%)
as a 40-year-old climber in the prior period -- i.e., 60 is the
new 40
* A contemporary 60-year-old climber has the about the same death rate
(about 2%) as a 48.5-year-old in the earlier period
* More women are attempting the climb in recent years (14.6%)
verses the
previous period (9.1%)
* Women and men had very similar odds of success or death in both
periods
The researchers say the doubling of the summit success rate is likely
due to a number of factors. Weather forecasting has dramatically improved
since the "Into Thin Air" storm of 1996, Huey said, giving climbers more information on the best window to push for the summit. Some climbers are
using elevated flow rates of supplemental oxygen -- and doing so lower on
the mountain. The most popular routes have fixed lines, meaning climbers
can clip into ropes tethered to the mountain for their ascent and descent, making it safer if they fall.

Increased experience of expedition leaders and high-altitude porters
may also have helped boost success rates. Interestingly, while more
climbers are making it to the top in recent years, today's climbers are actually less experienced in climbing tall peaks in Nepal than climbers
who attempted Everest in the 1990s and early 2000s.

Finally, the researchers looked at the effects of crowding near the summit
for the past two climbing seasons (permits were not issued in spring
of 2020 because of COVID-19). Detecting possible effects of crowding
is difficult with available information, they said, but their analysis
didn't show any impacts of crowding on success or death rates. However, crowding must slow climbers, increasing their exposure in the death zone,
they added.

The data for these analyses came from The Himalayan Database, a
comprehensive website based on archival interview records of Elizabeth
Hawley. Hawley, a news correspondent for Reuters based in Kathmandu,
and originally from Chicago, maintained the official record of all
climbers and summit successes for Everest and hundreds of other Nepalese
peaks until she died several years ago. The project continues under
new leadership.

"It's a remarkable data source," Huey said. "She was legendary --
climbers used to say you have not climbed Mount Everest until Ms. Hawley
says you've climbed Mount Everest."

========================================================================== Story Source: Materials provided by University_of_Washington. Original
written by Michelle Ma. Note: Content may be edited for style and length.


========================================================================== Journal Reference:
1. Raymond B. Huey, Cody Carroll, Richard Salisbury, Jane-Ling Wang.

Mountaineers on Mount Everest: Effects of age, sex, experience,
and crowding on rates of success and death. PLOS ONE, 2020; 15
(8): e0236919 DOI: 10.1371/journal.pone.0236919 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2020/08/200826141407.htm

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