Vegetation composition shifts, and in particular, shrub expansion across the Arctic tundra
are some of the most important and widely observed responses of high-latitude ecosystems …

Large quantities of organic carbon are stored in frozen soils (permafrost) within Arctic and
sub-Arctic regions. A warming climate can induce environmental changes that accelerate …

Executive summary Land and climate interact in complex ways through changes in forcing
and multiple biophysical and biogeochemical feedbacks across different spatial and …

This chapter addresses the biogeochemical cycles of carbon dioxide (CO2), methane (CH4),
and nitrous oxide (N2O). The three greenhouse gases have increased in the atmosphere …

Understanding the dynamics of methane (CH 4) emissions is of paramount importance
because CH 4 has 25 times the global warming potential of carbon dioxide (CO 2) and is …

Degrading permafrost can alter ecosystems, damage infrastructure, and release enough
carbon dioxide (CO 2) and methane (CH 4) to influence global climate. The permafrost …

Permafrost soils contain enormous amounts of organic carbon, which could act as a positive
feedback to global climate change due to enhanced respiration rates with warming. We …

The Northern Circumpolar Soil Carbon Database was developed in order to determine
carbon pools in soils of the northern circumpolar permafrost region. The area of all soils in …

Global wetlands are believed to be climate sensitive, and are the largest natural emitters of
methane (CH 4). Increased wetland CH 4 emissions could act as a positive feedback to …

Thawing permafrost and the resulting microbial decomposition of previously frozen organic
carbon (C) is one of the most significant potential feedbacks from terrestrial ecosystems to …