@article {2610,
	title = {Timing and magnitude of early to middle Holocene warming in East Greenland inferred from chironomids},
	journal = {Boreas},
	volume = {4611126123715949514747452279282108875423653331285492025312166523481473253855431029263383391243655482254028102024461441564827316},
	year = {2017},
	month = {Jan-10-2017},
	pages = {678 - 687},
	abstract = {Much of Greenland experienced summers warmer than present in parts of the early to middle Holocene, during a precession-driven positive anomaly in summer insolation. However, the magnitude of that warmth remains poorly known, and its timing and spatial pattern are uncertain. Here we describe the first quantitative Holocene palaeotemperature reconstruction from central East Greenland based upon insect (chironomid) assemblages preserved in lake sediments. We postulate that landscapes like our study site, characterized by minimal soil and vegetation development through the Holocene and thus little influenced by some important secondary gradients, are especially well suited to the use of chironomids to reconstruct Holocene temperatures. The inferred timing of warmth at our study site near Scoresby Sund agrees well with other nearby evidence, including glacial geological reconstructions and temperatures inferred from precipitation isotopes at Renland ice cap, supporting the use of chironomids to reconstruct temperatures at this site. We infer highest temperatures from c. 10 to 5.5 ka, followed by gradual cooling after 5.5 ka and progressively colder and less productive conditions after 3.5 ka. Models based upon two independent training sets yield similar inferred temperature trends, and suggest an average summer temperature anomaly from c. 10 to 5.5 ka of 3 to 4 {\textdegree}C relative to the preindustrial last millennium. The estimated overall rate of Neoglacial cooling averaged over the period from 5.5 to 0.5 ka was 0.6 to 0.8 {\textdegree}C per thousand years, more than twice the rate previously estimated for the Arctic as a whole. Given strong apparent spatial variability in Holocene climate around the Arctic, and the utility of palaeoclimate data for improving climate and ice-sheet models, it should be a priority to further quantify past temperature changes around the margins of the Greenland Ice Sheet, where few quantitative reconstructions exist and future warming will affect global sea level. },
	doi = {10.1111/bor.2017.46.issue-410.1111/bor.12247},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/bor.12247},
	author = {Axford, Yarrow and Levy, Laura B. and Kelly, Meredith A. and Francis, Donna R. and Hall, Brenda L. and Langdon, Peter G. and Lowell, Thomas V.},
	editor = {{\'\i}nguez-Rodrigo, M. and Baquedano, E. and Mabulla, A. and {\'\i}n, F. and Egeland, C. P.}
}
@article {2522,
	title = {Holocene temperature history at the western Greenland Ice Sheet margin reconstructed from lake sediments},
	journal = {Quaternary Science Reviews},
	volume = {59},
	year = {2013},
	month = {Jan-01-2013},
	pages = {87 - 100},
	abstract = {Predicting the response of the Greenland Ice Sheet to future climate change presents a major challenge to climate science. Paleoclimate data from Greenland can provide empirical constraints on past cryospheric responses to climate change, complementing insights from contemporary observations and from modeling. Here we examine sedimentary records from five lakes near Jakobshavn Isbr{\ae} in central West Greenland to investigate the timing and magnitude of major Holocene climate changes, for comparison with glacial geologic reconstructions from the region. A primary objective of this study is to constrain the timing and magnitude of maximum warmth during the early to middle Holocene positive anomaly in summer insolation. Temperature reconstructions from subfossil insect (chironomid) assemblages suggest that summer temperatures were warmer than present by at least 7.1 ka (the beginning of the North Lake record; ka = thousands of years before present), and that the warmest millennia of the Holocene occurred in the study area between 6 and 4 ka. Previous studies in the Jakobshavn region have found that the local Greenland Ice Sheet margin was most retracted behind its present position between 6 and 5 ka, and here we use chironomids to estimate that local summer temperatures were 2{\textendash}3 {\textdegree}C warmer than present during that time of minimum ice sheet extent. As summer insolation declined through the late Holocene, summer temperatures cooled and the local ice sheet margin expanded. Gradual, insolation-driven millennial-scale temperature trends in the study area were punctuated by several abrupt climate changes, including a major transient event recorded in all five lakes between 4.3 and 3.2 ka, which overlaps in timing with abrupt climate changes previously documented around the North Atlantic region and farther afield at \~{}4.2 ka.},
	issn = {02773791},
	doi = {10.1016/j.quascirev.2012.10.024},
	url = {https://doi.org/10.1016/j.quascirev.2012.10.024},
	author = {Axford, Yarrow and Losee, Shanna and Briner, Jason P. and Francis, Donna R. and Langdon, Peter G. and Walker, Ian R.}
}
