PUNAKHA, Bhutan — PUNAKHA, Bhutan -- High in the Himalayas, above this peaceful valley where farmers till a patchwork of emerald-green fields, an icy lake fed by melting glaciers waits to become a "tsunami from the sky."
The lake is swollen dangerously past normal levels, thanks to the global warming that is causing the glaciers to retreat at record speed. But no one knows when the tipping point will come and the lake can take no more, bursting its banks and sending torrents of water crashing into the valley below.
Such floods from above have hit Punakha before, most recently in 1994, a calamity that killed about two dozen people and wiped out livelihoods and homes without warning. But scientists say a new flood could unleash more than twice as much water and be far more catastrophic.
Unfortunately, residents of Punakha, a picturesque Buddhist kingdom, are not alone in having the threat of death and destruction hanging over their heads like an environmental sword of Damocles. Because of Earth's rising temperatures, at least 25 glacial lakes in Bhutan are at risk of overflowing and dumping their contents into the narrow valleys where much of the country's population lives.
Like many poor countries, isolated Bhutan is paying for the environmental damage wrought by the developed world and the expanding economies of nations such as China and India, whose fossil-fuel consumption and greenhouse-gas emissions are pushing global temperatures relentlessly upward.
But the added, perhaps more bitter, irony here is that Bhutan probably has done more to safeguard its environment than almost any other country.
A land of breathtaking vistas, little pollution and great biodiversity, Bhutan regards conservation as one of its most important public-policy goals - an anchor of "gross national happiness," the quirky measure of development concocted by the former king and upheld by his son, the current occupant of the throne.
Sustainable development is the official mantra. By law, the country's forest cover, including blue pine, cypress, spruce and hemlock, must never drop below 60 percent. Snow leopards, Himalayan black bears, barking deer and red pandas roam unmolested in the national parks and wildlife reserves that account for one-quarter of Bhutan's territory. A sanctuary in the east is famous as the only one in the world set aside for the yeti - or migoi, the mythical Abominable Snowman.
