Clouds in High Mountains Respond Differently to Global Warming

Most studies on the response of clouds to global warming focus on oceanic areas, leaving mountainous regions aside. However, understanding the behavior of clouds over mountains is crucial, especially in areas like Tibet, which provides water for hundreds of millions of people. A recent study fills this gap by analyzing long-term changes in cloud phases in mountainous regions around the world ².

Cloud Changes

The study used satellite observations and climate data from 2003 to 2022 to analyze the cloud fraction, cloud-top temperature, and height over Tibet, the European Alps, the Andes, the Appalachians, and the Rockies, as well as their adjacent low areas. The researchers found that, in response to global warming, clouds over most mountainous regions showed increases in warm liquid and ice cloud phases, with suppressed vertical development and fewer supercooled-phase clouds ¹.

Regional Differences

Although most mountainous regions show a similar pattern, Tibet and the Andes exhibit distinct behaviors. In these areas, supercooled clouds manage to cool and ascend more than in other regions. In Tibet, this may be related to stronger warming at lower altitudes, which destabilizes the vertical thermal profile, allowing clouds to develop higher in colder air. In the Andes, colder and higher clouds are associated with greater atmospheric moisture content ^1,2.

Impacts and Next Steps

These findings suggest that high-elevation clouds respond differently and more intensely to global warming than clouds over other regions. However, more research is needed to understand how these changes affect the way clouds retain or reflect radiative energy in Earth's atmosphere, which could help improve regional radiative energy budgets ².