Mountains warming faster, say researchers

    Warming increases with elevation, according to recent study from international team of scientists.

    By Jennifer Pascoe on April 24, 2015

    (Edmonton) An international team of scientists including a University of Alberta PhD candidate is calling for urgent and rigorous monitoring of temperature patterns in mountain regions after finding evidence that high elevations could be warming faster than previously thought.

    The research team says that without substantially better information, we risk underestimating the severity of a number of already looming problems, including water shortages and the possible extinction of some alpine flora and fauna. The research is published in the journal Nature Climate Change.

    “We’ve shown that the rate of warming appears to increase with elevation, or what is referred to as elevation-dependent warming,” says Scott Williamson, a PhD student in the Department of Biological Sciences who was involved in the research. “Even though mountain tops are colder than the base, they have over the last several decades been getting warmer at a faster pace.”

    The most striking evidence that mountain regions are warming more rapidly than surrounding regions comes from the Tibetan plateau. Here temperatures have risen steadily over the past 50 years—and the rate of change is accelerating. Masked by this general climate warming are pronounced differences at different elevations. For example, over the past 20 years temperatures above 4,000 metres have warmed nearly 75 per cent faster than temperatures in areas below 2,000 metres.  

    Williamson and his colleagues identify two major potential issues with increasing warming with altitude. The first relates to water supply, especially in summer: “Summer river discharge is largely provided by melting mountain snowpacks releasing water to the lowlands. If this process is happening more quickly than anticipated, and if the warming accelerates, this is potentially very problematic for the billions of people on Earth who depend on this water.” 

    Beyond affecting the global water supply, another issue relates to mountain biogeography. As Williamson explains, “Much of the flora and fauna in mountain environments are cold tolerant, so any increase in temperature will invariably see an upward movement of species, leading to a decrease in habitat and eventually isolation and extirpation.”

    The team of scientists came together as part of the Mountain Research Initiative, a mountain global change research effort funded by the Swiss National Foundation. The team includes scientists from the United Kingdom, United States, Switzerland, Canada, Ecuador, Pakistan, China, Italy, Austria and Kazakhstan. Between them, they have studied data on mountain temperatures worldwide collected over the past 60 to 70 years.

    The researchers found that records of weather patterns at high altitudes are extremely sparse. They advocate for improved observations, satellite-based remote sensing and climate model simulations to gain a true picture of warming in mountain regions, much of which requires international agreement, collaboration and funding.