CCSP Product 2.2 Draft for Public Review 1 2 Chapter 12. Carbon Cycles in the Permafrost Region of North America 3 4 5 6

• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: permafrost
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.226.4371; http://www.climatescience.gov/Library/sap/sap2-2/public-review-draft/SOCCR_Chapter12.pdf

of northern North America (more than 6 million km 2) is characterized by the presence of permafrost, soils or rocks that remain frozen for at least two consecutive years. This permafrost region contains approximately 25 % of the world’s total soil organic carbon, a massive pool of carbon that is vulnerable to release to the atmosphere as CO2 in response to an already detectable polar warming. The soils of the permafrost region of North America contain 213 Gt of organic carbon, approximately 61 % of the carbon in all soils of North America. The soils of the permafrost region of North America are currently a net sink of approximately 11 Mt C yr –1. The soils of the permafrost region of North America have been slowly accumulating carbon for the last 5-8 thousand years. More recently, increased human activity in the region has resulted in permafrost degradation and at least localized loss of soil carbon. Patterns of climate, especially the region’s cool and cold temperatures and their interaction with soil hydrology to produce wet and frozen soils, are primarily responsible for the historical accumulation of carbon in the region. Non-climatic drivers of carbon change include human activities, including