The 29-year-old, who runs a busy Internet cafe for tourists visiting the Everest region, remembers his grandfather telling him that 50 years ago the lake did not exist.
"Before, it was all ice," he told AFP in the eastern Himalayan town of Lukla, in the shadow of Mount Everest. "This is proof that the glaciers in the high Himalayas are melting. And that must be because the temperatures have gone up."
Scientists say the Imja Glacier above Dengboche is retreating by about 70 metres a year, and the melting ice has formed a huge lake that could devastate villages if it bursts.
The trend is not new. Nepal's International Centre for Integrated Mountain Development (ICIMOD), which has studied the Himalayas for three decades, says many of the country's glaciers have been retreating for centuries.
But ICIMOD glaciologist Samjwal Ratna Bajracharya said this was now happening at an alarming speed, with temperatures in the Himalayas rising at a much faster rate than the global average.
"Our studies of the past 30 years show that the temperatures (in the Himalayas) are rising up to eight times faster than the global average. Melting is taking place higher and faster," Bajracharya told AFP.
"The melting of glaciers and formation of glacier lakes is a key indicator of the temperature rise. And lately, we have seen massive ice melt."
