Mount Everest: Success Rate Has Doubled
A new study conducted by researchers from the University of Washington and the University of California, Davis, reveals that the success rate for climbing the world’s highest peak (8,848 m, 29,031.7 ft) has doubled over the past thirty years. Between 2006 and 2019, two-thirds of climbers reached the summit, compared to only one-third between 1990 and 2005.
To arrive at this conclusion, the scientists analyzed data from the Himalayan Database, a vast collection of information covering all expeditions from 1905 to the spring of 2020. This database was compiled, among others, by the late Elizabeth Hawley, a former Reuters correspondent in Kathmandu.
The researchers examined the success and mortality rates of all first-time climbers (those attempting Everest for the first time) who obtained a permit between 2006 and 2019. Since they had previously applied the same statistical methods to the 1990–2005 period, they were able to compare results.
Mortality Rate Remains Unchanged
Despite a significant increase in the number of climbs, the overall mortality rate has remained stable at around 1%. Between 1990 and 2005, more than 2,200 first-time climbers attempted to reach the highest point in the Himalayas. From 2006 to 2019, that number exceeded 3,600.
Researchers attribute the improved success rate to “better weather forecasts, the presence of fixed ropes along much of the route, accumulated experience in logistics and route planning, and improved use of supplemental oxygen.”
The increased experience of expedition leaders and high-altitude porters may also have contributed to higher success rates. Notably, while more climbers have reached the Nepalese summit in recent years, today’s climbers tend to be less experienced than those who attempted Everest in the 1990s and early 2000s.
Traffic Jams Are Not as Fatal as Expected
Although overcrowding at the summit can occasionally result in fatalities, the study’s authors were surprised to find that congestion did not have a statistically significant impact on success rates or mortality risks.
“The negative effects of overcrowding may be offset by the advantages of waiting at the highest camps,” they wrote, “and making a summit attempt— even with many others— only when conditions appear favorable (weather, snow, etc.).”
What Are the Main Causes of Death?
Between 1990 and 2019, a total of 119 people died while climbing Everest during the spring season. Two-thirds of these fatalities were due to illness (such as acute mountain sickness, exhaustion, or frostbite), about 25% resulted from falls (for example, into crevasses), and 5% were caused by avalanches or rock collapses.
Equal Performance Between Men and Women
Across both study periods, men and women had similar success rates and mortality risks. However, the number of female climbers has increased in recent years—14.6% of Everest climbers were women, compared to just 9.1% in the previous period. These statistics suggest that men and women may have comparable physiological capabilities and resistance to cold and hypoxia (a reduced oxygen concentration in the blood).
Climbing at 60? Still Possible
The proportion of ‘older’ climbers (aged 60 and above) has increased,” note the researchers. “Nevertheless, old age is not an absolute barrier to climbing Everest. In fact, older climbers in our recent sample have significantly higher success rates than those of a comparable age just a few decades ago.
Today, a 60-year-old climber has the same success rate (about 40%) as a 40-year-old climber did between 1990 and 2005. Similarly, a modern 60-year-old climber has the same mortality rate (around 2%) as a 48.5-year-old climber in the earlier period. The American researchers also observed that very elderly Japanese climbers have significantly higher success rates compared to their peers from other countries.
Debating the Height of the Summit
However, the study does not address the ongoing debate over Everest’s altitude. Nepal officially measures it at 8,848 meters, including the ice cap at the summit, while China lists it as 8,844.43 meters. Chinese scientists traveled to Everest in late May to take new measurements, but the date for publishing their findings remains unknown. According to AFP, China and Nepal have agreed to make a joint announcement.