glaciation. Whether they continue to sequester carbon or release it as greenhouse gases, perhaps in large
amounts, is important in Earth’s temperature dynamics. Given both ages and depths of numerous dated
sample peatlands, their rate of carbon sequestration can be estimated throughout the Holocene. Here we
use average values for carbon content per unit volume, the geographical extent of peatlands, and
ecological models of peatland establishment and growth, to reconstruct the time-trajectory of peatland
carbon sequestration in North America and project it into the future. Peatlands there contain w163 Pg of
carbon. Ignoring effects of climate change and other major anthropogenic disturbances, the rate of
carbon accumulation is projected to decline slowly over millennia as reduced net carbon accumulation in
existing peatlands is largely balanced by new peatland establishment. Peatlands are one of few longterm
terrestrial carbon sinks, probably important for global carbon regulation in future generations.
This study contributes to a better understanding of these ecosystems that will assist their inclusion in
earth-system models, and therefore their management to maintain carbon storage during climate
change.