Diminishing high-latitude land surface processes
Land surface geological processes typical of high-latitude regions are expected to almost disappear by the end of 21st century. A paper recently published in Nature Communications uses climate and geomorphological models at unprecedented scales to show that.

The study focused on modeling frost and snow related land surface processes, such as frost churning, palsa mires and snow accumulation sites. The modeling was based on a comprehensive empirical data combining field measurements and aerial imaginary. The use of ensemble modeling framework enabled to reduce modeling uncertainty and present the local variation of the processes at unprecedented fine spatial resolution.

“This is important, as the previous studies have not been able to realistically identify the distribution and climatic sensitivity of the processes in high-latitude regions”, post-doctoral researcher Juha Aalto says.

Climate change alters northern landscapes

The results suggest that profound changes can be expected at high-latitude regions regardless of the climate change mitigation policies.

“Unfortunately it seems that many of the studied frost-driven processes are already at the margin of their suitable climatic space”, Aalto says.

Consequently, assuming mild greenhouse gas emission scenario (RCP2.6), areal extent of the conditions suitable for the processes in the study areas will contract 70 % by 2050 owing to changes in average air temperature and precipitation. In tandem, frost and snow related land surface processes will be limited to high mountains, where the suitable climate conditions are likely to preserve longer than surrounding low-lying areas.

"Many of the rare species can only be sustained in areas of intense frost activity or late-lying snow packs; the disappearance of such unique environments will reduce the biodiversity of the region."

This could lead to changes in landscape dynamics in the future: “as the climate warming proceeds, ground ice may not be as significant geomorphological agent than before”, Juha Aalto says.

 The decay of land surface process will have strong effects on high-latitude vegetation.

"Many of the rare species can only be sustained in areas of intense frost activity or late-lying snow packs; the disappearance of such unique environments will reduce the biodiversity of the region", says Miska Luoto, professor in physical geography.

“In addition, the anticipated changes in land surface processes can feedback to regional climate system via alterations in carbon cycle and ground surface reflectance induced by the increase of shrub vegetation to alpine tundra”, says Miska Luoto.

Dr Stephan Harrison at Exeter University said that “the project used very high resolution climate and land surface models to demonstrate that high latitude geological and ecosystems will be fundamentally altered by climate change during this century”.

The study has been conducted in co-operation between University of Helsinki, Finnish Meteorological Institute and University of Exeter, and is a part of INFRAHAZARD project funded by the Academy of Finland.

The projects investigates the climatic sensitivity of Arctic land surface processes and associated hazards for human activity. In addition, the study was funded by European Union’s Seventh Framework Programme for research, technological development and demonstration.

Publication (Open access): Aalto, J., Harrison, S., Luoto, M. Statistical modelling predicts almost complete loss of major periglacial processes in Northern Europe by 2100. Nature Communications.

More information

Research scientist Juha Aalto, University of Helsinki, Department of Geosciences and Geography/Finnish Meteorological Institute, Climate Service Centre
Email: juha.aalto@helsinki.fi
Tel: +358 50 448 0407

Professor Miska Luoto, University of Helsinki, Department of Geosciences and Geography,
Email: miska.luoto@helsinki.fi
Tel: +358 9 191 50768,

Associate professor Stephan Harrison, University of Exeter, College of Life and Environmental Sciences,
Email: stephan.harrison@ex.ac.uk
Tel: (+44) 01326 371871,

Communication Specialist Riitta-Leena Inki
Email: riitta-leena.inki@helsinki.fi
Tel: +358 50 448 5770
Twitter: @inkiriitta