Introduction

Abstract

The permafrost carbon feedback is the potential release of greenhouse gases from thawing permafrost that enhances global warming. Research on permafrost – perennially frozen ground – therefore has shifted its focus from physical frozen ground processes towards the carbon cycle of permafrost soils. In this chapter, a general introduction is given to basic concepts with respect to permafrost. Next, an overview of environmental conditions of High Latitude permafrost regions describes their variation of present climate, vegetation, ecosystems, soil carbon, geomorphology and geology since the Last Glacial. The projections for future climate in permafrost regions are discussed, based on the IPCC climate model projections. The uncertainty in these climate model projections results mainly from future greenhouse gas emission scenarios, determined by the success or failure of human societies to curb greenhouse gas emissions. The permafrost carbon feedback has important social consequences: the stronger this feedback is, the larger the human effort to moderate climate change needs to be.