The new route was officially confirmed at the China's National People's Congress in Beijing this month. An official described the line, which traverses some of the most culturally significant areas of Tibet, as being "like the largest rollercoaster in the world".
Matteo Mecacci, president of the International Campaign for Tibet (ICT) group said in a statement: "In environmental, demographic and cultural terms, the impact of this new railway on Tibet's landscape and Tibetan lives is likely to be even more significant than the link from Golmud in Qinghai to Lhasa, which opened in 2006.
"Traversing an area that is rich in forests and mineral resources, it will facilitate further large-scale exploitation of Tibet's natural resources as well as enabling greater population migration into Tibet, both seasonal in terms of tourists and migrants, and permanent settlers."
Officials confirmed that work on the railway would be accelerated this year, according to ICT, beginning with work on the first stage of the route between Lhasa to Nyingtri. This stage of construction has potential to lead to regional security issues between India and China because it will take place near to the disputed Arunachal Pradesh region of India, an area China claims is part of the PRC.
Chinese state media praised the new railway saying it would cut journey times from Chengdu to Lhasa from 42 hours by train and three days by road to less than 15 hours. Lin Shijin, a senior civil engineer at China Railway Corporation, was quoted by China Daily as saying: "It's like the largest rollercoaster in the world. With a designed service life of 100 years, it is believed to be one of the most difficult railway projects to build on Earth."
The new railway could raise a number of safety concerns due to its route crossing fragile terrain that is reported to be warming nearly three times faster than the rest of the earth. It was just weeks after the Qinghai-Tibet railway went into operation in 2006 that Chinese state media began reporting of cracks developing in the concrete structures due to its permafrost foundation sinking and cracking.
ICT warned that climate change and human activities in the Tibetan plateau could lead to a reduction in the future water supply to China and South Asia, and scientists have said that the combination of warming temperatures, major infrastructure construction and urbanization, is leading to irreversible damage to the ecosystem. It is predicted that large areas of grasslands, alpine meadows, wetlands and permafrost may disappear from the Tibetan plateau by 2050.