Climate science tells us the world’s coastal zones are in trouble from storm surges and sea-level rise. Food-producing regions are at risk of drought, disease and climate-hardy pests.

But what about the roughly 25 percent of the Earth’s land area defined as “mountain regions”?

A new U.N. report finds that mountains and the societies that call them home face their own suite of climate challenges.

They include temperature and precipitation extremes, which in turn can trigger avalanches, flooding, drought and wildfire. Mountain regions also face risk from melting glaciers and “glacial lake outburst flooding,” according to experts, as well as accelerated erosion and landslides, which are among the deadliest natural disasters worldwide.

“These risks expose already vulnerable and often marginalized mountain communities and destabilize some of their wealth-generating sectors, including agriculture, tourism and biodiversity,” experts conclude in a seven-volume synthesis report known as the “Mountain Adaptation Outlook Series.”

The risks take on even greater importance when one considers that mountain ranges provide essential water to over half the global population—“making them not only crucial for people living in the mountains, but also for those living downstream,” the report says.

Such water challenges are well-documented in the U.S. Intermountain West and in states like California, where water allocation is a perennial source of public policy fights between urban and rural water users. In some U.S. Western ranges, mountain pine beetle infestations have killed tens of millions of otherwise healthy trees, a condition made worse as rising temperatures allow bark beetle explosions to occur at higher elevations.

The U.N. synthesis report focuses on mountain regions beyond North America: the tropical Andes in South America; Eastern Europe’s western Balkan and Carpathian mountains; the South Caucasus; the Hindu Kush Himalaya region along the Afghanistan-Pakistan border; Central Asia; and the East African Rift.

Joyce Msuya, acting executive director at the U.N. Environment Programme, said in a statement that mountain ranges are “extremely complex ecosystems [and] home to some of the most marginalized and vulnerable communities” in the world.

More broadly, the authors note that many mountain ranges serve as political borders between countries. They’re near the edge of countries and often away from centers of government and economic power where important policy decisions are made.

Experts also say that mountain societies are experiencing a disproportionately high number of disasters compared with other environments. They urgently need to adapt to changing conditions, they say.

At the same time, “the rapid and unprecedented rate of climate change is challenging this adaptive capacity, as is evident through the already widespread impacts being felt across mountain regions,” the authors said.

The “Mountain Adaptation Outlook Series” stems from collaboration between U.N. Environment and GRID-Arendal, a Norwegian nonprofit. The two agencies and other partners have been working to examine climate change action in developing countries with sensitive mountain landscapes since 2015.

The report, issued on the sidelines of international climate talks in Poland, includes a deeper case study on adaptation in the Hindu Kush Himalayas, which stretch across eight countries, from Afghanistan to Myanmar, and are home to 240 million people.

Some have called the region the world’s “water tower” because it is the source of 10 of Asia’s largest rivers and contains the largest volume of ice and snow outside the Arctic and Antarctica. An estimated 1.3 billion people depend on those water sources for drinking water, irrigation, energy, industry and sanitation.

Yet experts have found that the Himalayas’ massive size and diversity make it difficult for countries to work together on climate solutions, including adaptation measures.

“While the world must reduce greenhouse gases to limit warming to safe levels, the reality for the Hindu Kush Himalaya is that adaptation actions across all sectors is essential now and in the coming decades,” the report said. “Many of the current and future challenges are of a transboundary nature, calling for increasing cooperation between the countries in the region."

Erin Gleeson, associate director of the Mountain Institute, a Washington, D.C.-based nonprofit, said the United Nations’ findings are consistent with the institute’s own “Scaling Up Mountain Ecosystem-based Adaptation” program, which has focused on climate solutions in the Peruvian Andes and the Himalayas of Nepal.

Gleeson added, however, that “political goodwill is often slow to coalesce into real, on-the-ground action” and that much more work needs to be done to transfer adaptation technologies and methods from developed countries to developing ones.

“While we applaud this report, we have to emphasize that it is time to act on the considerable knowledge we already have,” she said. “It’s time to implement in remote mountain areas where support is needed most. Let’s apply that knowledge and support local people in protecting their fragile ecosystems that are the basis for their livelihoods and the tops of our watersheds.”

Reprinted from Climatewire with permission from E&E News. E&E provides daily coverage of essential energy and environmental news at