[Permafrost feedback: "...The second recommendation of the new UNEP Report is geared to climate science. “Many climate models do not yet currently take the so-called permafrost feedback effects into consideration. This is why we recommend to the International Panel on Climate Change IPCC, together with the International Permafrost Association, that a special appraisal be prepared on the influence of the thawing permafrost soils on the global climate “, says Hugues Lantuit."] [...If this permafrost of ice and earth now starts to thaw, a process is set into motion which is also known to gardeners with their own compost heaps. Bacteria and micro-organisms start to break down a large part of the animal and plant matter contained in the soil, thereby converting their organic-bound carbon into methane and carbon dioxide. Both are greenhouse gases which intensify global warming and further the thawing of the remaining permafrost in in this way. Scientists describe this self-sustaining process as the permafrost feedback effect.]
[Engineering challenges: "...There are many technical difficulties for such a railway. About half of the second section was built on barely permanent permafrost. In the summer, the uppermost layer thaws, and the ground becomes muddy. Chinese engineers dealt with this problem by building elevated tracks with foundations sunk deep into the ground, building hollow concrete pipes beneath the tracks to keep the rail bed frozen, and using metal sun shades.[19] Similar to the Trans-Alaska Pipeline System portions of the track are also passively cooled with ammonia based heat exchangers.]
* WIRED (July 2006): Train to the Roof of the World
[...“Every day I think about whether the railway will have problems in the next 10 to 20 years,” he says. The government has thus far only ignored or chafed at his warnings. “When I express concerns to the media,” Wu says, “the ministry and construction companies call to say, ‘Why did you say this? Everything is OK with the railway, so why did you say otherwise?’”]
* WIRED (July 2006): Train to the Roof of the World
[...“Every day I think about whether the railway will have problems in the next 10 to 20 years,” he says. The government has thus far only ignored or chafed at his warnings. “When I express concerns to the media,” Wu says, “the ministry and construction companies call to say, ‘Why did you say this? Everything is OK with the railway, so why did you say otherwise?’”]
