1-s2.0-S0277379121002754-main.pdf (6.89 MB)
Local summer insolation and greenhouse gas forcing drove warming and glacier retreat in New Zealand during the Holocene
journal contribution
posted on 2021-10-11, 02:33 authored by L Dowling, Shaun EavesShaun Eaves, Kevin NortonKevin Norton, A Mackintosh, Brian AndersonBrian Anderson, A Hidy, A Lorrey, Lauren VargoLauren Vargo, M Ryan, S TimsGeological climate archives from the Holocene Epoch provide baseline information concerning natural climate variability. Temperate mountain glacier extent is sensitive to summer air temperature, thus geological records of past glacier length changes are a useful proxy for this climatic variable. Here we present a new cosmogenic 10Be chronology of glacier length changes at Dart Glacier in the Southern Alps, New Zealand. Prominent moraines deposited 321 ± 44 yr ago (n = 11) and 7.8 ± 0.3 ka (n = 5) show glaciers during the Little Ice Age were less extensive than during the early Holocene. This pattern of net Holocene glacier retreat is consistent with emerging data from other catchments in New Zealand and across the southern mid-latitudes. Using the physical framework of a transient global climate model simulation, we suggest that cool summers in the early Holocene were promoted by the local summer insolation minimum, together with low atmospheric greenhouse gas concentrations, causing an early Holocene austral glacial maximum. An insolation-driven reduction in seasonality at southern mid-latitudes may reconcile differences between early Holocene temperature reconstructions where climate proxies have different seasonal sensitivities. We suggest that rising greenhouse gas concentrations after 7 ka caused regional-scale glacier retreat and appear to be the dominant driver of multi-millennial summer temperature trends in the southern mid-latitudes during the present interglacial.
History
Preferred citation
Dowling, L., Eaves, S., Norton, K., Mackintosh, A., Anderson, B., Hidy, A., Lorrey, A., Vargo, L., Ryan, M. & Tims, S. (2021). Local summer insolation and greenhouse gas forcing drove warming and glacier retreat in New Zealand during the Holocene. Quaternary Science Reviews, 266, 107068-107068. https://doi.org/10.1016/j.quascirev.2021.107068Publisher DOI
Journal title
Quaternary Science ReviewsVolume
266Publication date
2021-08-15Pagination
107068-107068Publisher
Elsevier BVPublication status
PublishedISSN
0277-3791eISSN
1873-457XArticle number
107068Language
enUsage metrics
Categories
No categories selectedKeywords
Licence
Exports
RefWorks
BibTeX
Ref. manager
Endnote
DataCite
NLM
DC