Alaska's Mendenhall glacier (冰川) is about 20 minutes by car from Juneau, the state capital. It is one of the area's most popular sites for tourists. But climate change has caused the ice to melt and the glacier to retreat(消退). That means it is losing more snow and ice than it gains. Researchers say the Mendenhall glacier retreated about 800 meters between 2007 and 2021.

Mendenhall pours down from rocky land between mountains and into a lake filled with icebergs. Special signs mark the glacier's retreat, showing where the ice once stood. Experts estimate that by 2050, people will not be able to see the Mendenhall glacier from the visitor centre that was built for it. That is already the case at some other glacier visitor centres in Alaska.

The melting glacier leads to questions for the Alaskan tourism industry. How can tourism leaders help protect the glaciers for visitors to enjoy? And should there be limits on the number of tourists to the area?

Tourism is an important part of Juneau's economy. About 1. 6 million cruise ship (游轮) passengers are expected to stop in Juneau. On especially busy days, 20, 000 people arrive each day to a city that has only 30, 000 full-time residents.

Manoj Pillai is a cruise ship worker from India. He recently got off his ship and went to see the Mendenhall glacier. "The glacier is so beautiful now, " he said. But he wondered what it must have looked like 10 or 20 years ago and what it would look like in the following days.

People have many reasons to want to visit Alaska, and all the visitors help the state's economy. But in Juneau, tourism officials are questioning whether the city and surrounding areas can deal with so many visitors each year. City leaders and major cruise lines have agreed to a daily five-ship limit for next year. But critics worry that may not do much to reduce tourist numbers because the ships themselves keep getting bigger. Some Juneau residents say they would like one day a week without ships.