New Delhi: The Himalayas are becoming noticeably greener as vegetation spreads to higher altitudes, but scientists caution that this apparent sign of growth may actually signal deeper environmental changes linked to climate change. A new study led by researchers from the University of Exeter found that alpine vegetation has been steadily moving uphill across several Himalayan regions between 1999 and 2022.
Researchers examined the alpine vegetation line, which marks the highest elevation where continuous plant growth occurs, across six regions stretching from Ladakh in India to Bhutan. The study found that plants are expanding into areas that were previously too cold and snow-covered to support sustained vegetation. In Nepal’s Manthang region, the vegetation line advanced by nearly 22.8 feet per year, while the Khumbu region near Mount Everest recorded an upward shift of about 4.7 feet annually.
Scientists believe that rising temperatures and declining snow depth are key drivers behind the change. As snow melts earlier and remains thinner for shorter periods, plants gain a longer growing season, allowing them to establish themselves in previously inhospitable terrain. Lead researcher Ruolin Leng noted that the Himalayas are warming faster than the global average, creating conditions that favor vegetation expansion at high elevations.
However, experts warn that more greenery is not necessarily good news in such fragile mountain ecosystems. Increased vegetation can alter how snow accumulates and melts, affect soil moisture, and change the timing and flow of water through mountain catchments. These changes could have significant consequences for major river systems, including the Indus, Ganges and Brahmaputra, which provide water to nearly 1.6 billion people across South Asia.
The study also found a complex pattern of both “greening” and “browning” across the Himalayas. While greening trends were more widespread, significant browning was observed in eastern regions such as Khumbu and Bhutan. Researchers say different plant communities, including grasses, shrubs and woody vegetation, interact with snow and soil in different ways, making the ecological impacts difficult to predict.
Professor Karen Anderson, one of the researchers, emphasized that even small vegetation changes can have broader effects on important water catchments. Scientists say continued monitoring is essential to understand how these shifts will influence water availability, biodiversity and ecosystem stability in the years ahead.
The findings highlight that climate change does not always appear as obvious environmental decline. In some cases, it may emerge as new growth in unexpected places, bringing consequences that are only beginning to be understood.