Lecture 3 extra

The evolution of permafrost in changing climate - role of snow cover. 2 climate change scenarios tested, both cause earlier snow melt. Percip also partly rain -> increased moisture in the active layer -> Longer Zero curtain effect in Autumn. moderate temp increase could result in 170m higher lower PF boundary. High temp increase could cause 580m higher lower pf boundary. Engadin (Switzerland) has a predicted 65% spatial PF loss withh 3 degree increase. Potential consequences include rockfalls and debris flows particularily in steep places, excacerbated by talik increasing sediment supply for mass wasting processes.

The cryosphere as an indicator: Recorder of palaeo-climates. Sensitive climate change indicator. socio-ecological impact (freeing up land for human occupation/utilisation/agriculture etc.)

Issues: Engineering - proposed Qinghai-Tibet Railway, melting permafrost could impact the building/maintenance. Melting permafrost could increase river flows and cause flooding, if it all melts a major water source is gone.

Leutschg & Haeberli 2007

Jin et al. 2000