Lecture 3 extra

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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