http://ruby.fgcu.edu/courses/twimberley/envirophilo/wanner.pdf

Mid- to Late Holocene climate change: an overview

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 the atmosphere in a changing climate. In this article we present an overview of the global permafrost C pool and of the processes that might transfer this C into the atmosphere, as well as the associated ecosystem changes that occur with thawing. We show that accounting for C stored deep in the permafrost more than doubles previous high-latitude inventory estimates, with this new estimate equivalent to twice the atmospheric C pool. The thawing of permafrost with warming occurs both gradually and catastrophically, exposing organic C to microbial decomposition. Other aspects of ecosystem dynamics can be altered by climate change along with thawing permafrost, such as growing season length, plant growth rates and species composition, and ecosystem energy exchange. However, these processes do not appear to be able to com...

/pdf/vulnerability-of-permafrost-carbon-to-climate-change-dcw6s6a0hw.pdf

Vulnerability of Permafrost Carbon to Climate Change: Implications for the Global Carbon Cycle

Prefaces Acknowledgements 1. Mountains and their climatological study 2. Geographical controls of mountain meteorological elements 3. Circulation systems related to orography 4. Climatic characteristics of mountains 5. Regional case studies 6. Mountain bioclimatology 7. Changes in mountain climates Appendix General index Author index.

Mountain Weather and Climate

Subfossil pollen and plant macrofossil data derived from 14 C-dated sediment profiles can provide quantitative information on glacial and interglacial cli- mates. The data allow climate variables related to growing- season warmth, winter cold, and plant-available moisture to be reconstructed. Continental-scale reconstructions have been made for the mid-Holocene (MH, around 6 ka) and Last Glacial Maximum (LGM, around 21 ka), allowing comparison with palaeoclimate simulations currently being carried out as part of the fifth Assessment Report (AR5) of the Intergovernmental Panel on Climate Change. The synthesis of the available MH and LGM climate recon- structions and their uncertainties, obtained using modern- analogue, regression and model-inversion techniques, is presented for four temperature variables and two moisture variables. Reconstructions of the same variables based on

/pdf/pollen-based-continental-climate-reconstructions-at-6-and-21-q7dw2mep3u.pdf

Pollen-based continental climate reconstructions at 6 and 21 ka: A global synthesis

Here, we present results from the most comprehensive compilation of Holocene peat soil properties with associated carbon and nitrogen accumulation rates for northern peatlands. Our database consists of 268 peat cores from 215 sites located north of 45°N. It encompasses regions within which peat carbon data have only recently become available, such as the West Siberia Lowlands, the Hudson Bay Lowlands, Kamchatka in Far East Russia, and the Tibetan Plateau. For all northern peatlands, carbon content in organic matter was estimated at 42 ± 3% (standard deviation) for Sphagnum peat, 51 ± 2% for non-Sphagnum peat, and at 49 ± 2% overall. Dry bulk density averaged 0.12 ± 0.07 g/cm3, organic matter bulk density averaged 0.11 ± 0.05 g/cm3, and total carbon content in peat averaged 47 ± 6%. In general, large differences were found between Sphagnum and non-Sphagnum peat types in terms of peat properties. Time-weighted peat carbon accumulation rates averaged 23 ± 2 (standard error of mean) g C/m2/yr during the Holocene on the basis of 151 peat cores from 127 sites, with the highest rates of carbon accumulation (25-28 g C/m2/yr) recorded during the early Holocene when the climate was

/pdf/a-database-and-synthesis-of-northern-peatland-soil-4l1zug5gcs.pdf

A Database and Synthesis of Northern Peatland Soil Properties and Holocene Carbon and Nitrogen Accumulation

In this study, the Holocene development of a peat plateau area in the east-European Russian Arctic is reconstructed based on detailed macrofossil, physico-chemical and radiocarbon analyses from two peat sequences. Basal dates from these two, c. 2 m long, peat profiles are c. 9420 BP and c. 9250 BP. From another six peat sequences gross-stratigraphic descriptions and additional radiocarbon dates are available. Basal dates from two short (<1 m) peat profiles indicate further peatland expansion at c. 3635 BP and c. 1285 BP. The oldest macrofossils of tree birch are dated to c. 9500 BP and those of conifers, presumably spruce, to c. 8000 BP. Tree stands became rare in the study area after c. 2800 BP, but occasionally occur until present. Peatlands formed through terrestrialization of ponds or paludification of forested uplands. Between 9000 and 3100 BP the peatlands were wet rich fens. Beginning from c. 3100 BP there are marked changes in their surface hydrology, connected with climatic cooling and permafrost...

Peter Kuhry

Papers

Holocene development of the Rogovaya River peat plateau, European Russian Arctic:

Mid- to Late-Holocene pollen-based biome reconstructions for Colombia

A Younger Dryas Icecap in the Equatorial Andes

Holocene climate and landscape evolution East of the Pechora Delta, East-European Russian Arctic

Glacier fluctuations in the Eastern Andes of Colombia (south America) during the last 45,000 radiocarbon years