Paul Miller. Photo.

Paul Miller

Senior lecturer

Paul Miller. Photo.

Variability in the sensitivity among model simulations of permafrost and carbon dynamics in the permafrost region between 1960 and 2009

Author

  • A. David McGuire
  • Charles Koven
  • David M. Lawrence
  • Joy S. Clein
  • Jiangyang Xia
  • Christian Beer
  • Eleanor Burke
  • Guangsheng Chen
  • Xiaodong Chen
  • Christine Delire
  • Elchin Jafarov
  • Andrew H. MacDougall
  • Sergey Marchenko
  • Dmitry Nicolsky
  • Shushi Peng
  • Annette Rinke
  • Kazuyuki Saito
  • Wenxin Zhang
  • Ramdane Alkama
  • Theodore J. Bohn
  • Philippe Ciais
  • Bertrand Decharme
  • Altug Ekici
  • Isabelle Gouttevin
  • Tomohiro Hajima
  • Daniel J. Hayes
  • Duoying Ji
  • Gerhard Krinner
  • Dennis P. Lettenmaier
  • Yiqi Luo
  • Paul A. Miller
  • John C. Moore
  • Vladimir Romanovsky
  • Christina Schädel
  • Kevin Schaefer
  • Edward A G Schuur
  • Benjamin Smith
  • Tetsuo Sueyoshi
  • Qianlai Zhuang

Summary, in English

A significant portion of the large amount of carbon (C) currently stored in soils of the permafrost region in the Northern Hemisphere has the potential to be emitted as the greenhouse gases CO2 and CH4 under a warmer climate. In this study we evaluated the variability in the sensitivity of permafrost and C in recent decades among land surface model simulations over the permafrost region between 1960 and 2009. The 15 model simulations all predict a loss of near-surface permafrost (within 3 m) area over the region, but there are large differences in the magnitude of the simulated rates of loss among the models (0.2 to 58.8 × 103 km2 yr−1). Sensitivity simulations indicated that changes in air temperature largely explained changes in permafrost area, although interactions among changes in other environmental variables also played a role. All of the models indicate that both vegetation and soil C storage together have increased by 156 to 954 Tg C yr−1 between 1960 and 2009 over the permafrost region even though model analyses indicate that warming alone would decrease soil C storage. Increases in gross primary production (GPP) largely explain the simulated increases in vegetation and soil C. The sensitivity of GPP to increases in atmospheric CO2 was the dominant cause of increases in GPP across the models, but comparison of simulated GPP trends across the 1982–2009 period with that of a global GPP data set indicates that all of the models overestimate the trend in GPP. Disturbance also appears to be an important factor affecting C storage, as models that consider disturbance had lower increases in C storage than models that did not consider disturbance. To improve the modeling of C in the permafrost region, there is the need for the modeling community to standardize structural representation of permafrost and carbon dynamics among models that are used to evaluate the permafrost C feedback and for the modeling and observational communities to jointly develop data sets and methodologies to more effectively benchmark models.

Department/s

  • Dept of Physical Geography and Ecosystem Science
  • MERGE - ModElling the Regional and Global Earth system
  • BECC - Biodiversity and Ecosystem services in a Changing Climate

Publishing year

2016

Language

English

Pages

1015-1037

Publication/Series

Global Biogeochemical Cycles

Volume

30

Issue

7

Document type

Journal article

Publisher

American Geophysical Union (AGU)

Topic

  • Climate Research

Keywords

  • carbon cycle
  • climate change
  • permafrost
  • permafrost carbon feedback
  • sensitivity
  • soil carbon

Status

Published

ISBN/ISSN/Other

  • ISSN: 0886-6236