How Rising Temperatures Likely Contributed to Nepal’s Deadly Flood
How Rising Temperatures Likely Contributed to Nepal’s Deadly Flood
气温升高如何可能导致了尼泊尔的致命洪水
Roughly 160 people are dead and hundreds more—including dozens of international tourists—are missing after flash floods hit a region on the mountainous border of Nepal and Tibet on Wednesday. Devastating footage posted to social media shows people fleeing a wall of water that washed away buildings and vehicles. 周三，尼泊尔与西藏交界的山区遭遇山洪暴发，造成约 160 人死亡，数百人失踪（其中包括数十名国际游客）。社交媒体上发布的灾难性视频显示，人们在逃离一道冲毁了建筑物和车辆的水墙。
Initial analysis of satellite imagery and reports from the Nepalese government indicate that the flooding was likely triggered by a landslide caused after a piece of a glacier fell hundreds of feet. 对卫星图像的初步分析和尼泊尔政府的报告显示，此次洪水很可能是由一块冰川坠落数百英尺引发山体滑坡所导致的。
As the region warms, its ice is becoming increasingly unstable, raising the risk of catastrophic flooding. 随着该地区气候变暖，冰层变得越来越不稳定，增加了发生灾难性洪水的风险。
“The glaciers over there are definitely in retreat,” says Joseph Shea, an associate professor of geography at the University of Northern British Columbia. “There’s a lot of glacier mass up there, but we’re seeing thinning, we’re seeing retreating.” “那里的冰川绝对处于退缩状态，”北不列颠哥伦比亚大学地理学副教授约瑟夫·谢（Joseph Shea）说。“那里有大量的冰川质量，但我们观察到它们正在变薄、正在退缩。”
Since 2000, the world’s glaciers have lost 5 percent of their ice, with much more drastic impacts in certain regions. Nepal’s glaciers lost nearly a quarter of their area between 1970 and 2010. More than 160 smaller glaciers in the country, research has found, have vanished entirely. 自 2000 年以来，全球冰川已经损失了 5% 的冰量，在某些地区影响更为剧烈。1970 年至 2010 年间，尼泊尔的冰川面积减少了近四分之一。研究发现，该国已有 160 多座小型冰川完全消失。
A recent study finds that 40 percent of the world’s glacial ice could disappear if the world does not keep warming under 1.5 degrees Celsius. 一项最新研究发现，如果全球气温升幅不能控制在 1.5 摄氏度以内，全球 40% 的冰川可能会消失。
Before and after imagery shows debris left behind by the floods. The impacts of warming on glaciers in Nepal can cause cascading effects. Shea points out that retreating glaciers can help trigger landslides as they get smaller and can no longer hold back sediment. As these glaciers retreat, many are leaving large, dammed lakes at higher elevations. “If you have a landslide suddenly into a lake, you get an overtopping of the dam, and then the whole thing can collapse catastrophically,” Shea says. Known as glacial lake outburst floods, two of these events hit Nepal last year, and research shows millions of people are living in harms way around the world. 对比图像显示了洪水留下的残骸。气候变暖对尼泊尔冰川的影响会引发连锁反应。谢指出，冰川退缩会助长山体滑坡，因为冰川变小后无法再阻挡沉积物。随着冰川退缩，许多冰川在高海拔地区留下了巨大的堰塞湖。“如果山体滑坡突然冲入湖中，湖水就会漫过大坝，整个大坝可能会发生灾难性的坍塌，”谢说。这种现象被称为冰川湖溃决洪水，去年尼泊尔就发生了两起此类事件，研究表明全球有数百万人正生活在危险之中。
Wednesday’s disaster was more likely due to a glacial collapse that fell into the valley below. Daniel Shugar, a geologist at the University of Calgary in Canada, told The New York Times that satellite imagery suggested that a 2,000-foot-wide piece of ice may have fallen almost 4,000 feet, “[pulverizing] the ice into water” with the force of its fall. And while Shugar emphasized that it was still too early to make conclusive statements about the cause of the floods, he noted to Reuters that snow that was present on the glacier earlier in the week may have melted due to warm temperatures. 周三的灾难更可能是由冰川崩塌坠入下方山谷引起的。加拿大卡尔加里大学的地质学家丹尼尔·舒加（Daniel Shugar）告诉《纽约时报》，卫星图像显示，一块 2000 英尺宽的冰块可能坠落了近 4000 英尺，其坠落的冲击力将冰块“粉碎成水”。虽然舒加强调现在就洪水原因下定论还为时过早，但他向路透社指出，本周早些时候冰川上的积雪可能因气温升高而融化。
The collapse and debris flow were so large and forceful that they registered as a magnitude 5.2 seismic event, according to the US Geological Survey. 据美国地质调查局称，此次崩塌和泥石流规模巨大、冲击力极强，引发了 5.2 级地震。
Glaciers elsewhere have broken apart with destructive results. That includes the collapse of a Swiss glacier last year that buried a town, while on a smaller scale, a glacier collapse in Italy in 2022 killed 11 mountaineers. Both were linked with rising temperatures. 其他地区的冰川也曾发生过崩塌并造成破坏性后果。其中包括去年瑞士冰川崩塌掩埋了一个城镇，而在较小规模上，2022 年意大利的一次冰川崩塌导致 11 名登山者遇难。这两起事件都与气温升高有关。
There are a lot of factors in a warming world, Shea says, that can play on each other to destabilize glaciers. 谢表示，在气候变暖的世界中，有许多因素相互作用，导致冰川变得不稳定。
“It’s summertime,” he says. “There’s lots of warming, lots of melt happening, lots of water around. There’s also things like alpine permafrost thaws: The ground temperatures warm up, and big blocks and chunks that would have been frozen in place are now suddenly becoming mobile.” “现在是夏天，”他说。“气温升高，大量冰雪融化，周围到处都是水。此外还有高山永久冻土融化等问题：地表温度升高，原本被冻结在原处的大块岩石和冰块现在突然开始移动了。”