NASA satellite data reveal that the vegetation is expanding 20,000 feet higher on Mount Everest
Plant life is starting to rise higher on Mount Everest, according to a new study, and it is most likely due to global warming.
British scientists used 25 years of NASA satellite data to measure the increase in vegetation that can grow under the snow – known as subnival vegetation.
The team at the University of Exeter found increases in subnival vegetation that stretched 13,600 feet to 19,600 feet up the mountain range.
Conditions at the top of this altitude range – around 20,000 feet – are generally considered to be close to the limit where plants can grow due to ice.
These secluded grasses and shrubs now cover between five and fifteen times the area of permanent glaciers and snow in the Hindu Kush Himalayan region.
View of Khumbu and Cholatse from below Ama Dablam at approximately 4900m with typical subnival vegetation in the foreground
WHAT IS THE HINDU KUSH HIMALAYAN REGION?
The Hindu Kush Himalayas (HKH) are the freshwater towers of South Asia and parts of Southeast Asia.
Water from their snow, glaciers and rainfall feed the ten largest river systems in Asia.
Together, these rivers support the drinking water, irrigation, energy, industrial and sanitary needs of more than a billion people who live in the mountains and downstream.
Together with a rapidly growing population that places higher demands on water resources, climate change influences the availability of water throughout the HKH and beyond.
Subnival vegetation is now spreading across the Himalayas, affecting rivers that supply more than 1.4 billion people with water.
The more water is used to feed plants in higher parts of the mountain, the smaller the water supply for people near the soil, including for irrigation and sanitation.
“It is important to monitor and understand ice loss in large mountain systems, but subnival ecosystems cover a much larger area than permanent snow and ice and we know very little about it and know how to moderate water supply,” said Dr. Karen Anderson of Environment and Environment. Institute for Sustainability at the Penryn Campus of Exeter in Cornwall.
“Snow falls and melts seasonally here, and we don’t know what impact changing subnival vegetation will have on this aspect of the water cycle – which is vital because this region – known as” Asian water towers “- is the ten largest rivers in Asia.”
Mount Everest ecosystems consist of short plants – mainly grasses and shrubs – and seasonal snow.
The University of Exeter team measured subnival vegetation data from 1993 to 2018 using NASA’s Landsat satellites divided into four elevation ranges.
Swampy vegetation near the Nepalese village of Dingboche, about 4400 meters above sea level
They saw a significant increase in vegetation across all four brackets – 13,615 to 14,763 feet; 14,763 to 16,404 feet; 16,404 to 18,044 feet; and 18,044 to 19,685 feet above sea level.
The strongest trend in increased vegetation was observed in the third highest drive – 16,404 to 18,044 feet above sea level.
The study, published in the journal Global Change Biology, does not investigate the cause of the change in plant growth; however, the findings are consistent with the models that indicate global warming.
“There are many possible causes for vegetation changes such as this, and these – over an area as large as the Himalayas – are expected to be quite diverse and spatially variable,” Dr. said. Anderson to MailOnline.
“They can include things like land use changes, increased CO2 in the atmosphere that can affect plant photosynthesis – some plants are more sensitive than others – changes in temperature, changes in precipitation and snow cover and changes in the prevalence of other types of disruption.
“Climate change is, of course, at the root of some of these things – in particular changes in temperature and precipitation, and we know that the Himalayas are one of the areas on the world line in the front line of climate change.”
View towards Nuptse-Lhotse Ridge from below Ama Dablam at approximately 4900m with typical subnival vegetation
Previous research has suggested that Himalayan ecosystems are highly vulnerable to climate-induced vegetation shifts.
Mount Everest is located in the vast mountain range known as the Himalayas, which includes the countries of Bhutan, China, India, Nepal and Pakistan.
The Himalayan region has the largest concentration of ice on Earth, apart from the polar ice caps, and supplies around 86,000,000 cubic meters of water annually, according to the WWF.
The frozen water towers of Asia, the frozen Hindu Kush and Himalayan mountain ranges also contain the second highest mountain in the world, K2, at 28,251 feet.
The team at the University of Exeter used Google Earth Engine, a free cloud-based geospatial processing platform, to speed up data processing tasks for research.
“These large-scale studies with decades of satellite data are computationally intensive because the file size is huge,” said Dominic Fawcett of the University of Exeter, who coded the image processing.