More Gems Unearthed by Watts Up With That

 It is about Iceland's Climate:

A wealth of new research in glacier and sea ice extent show modern Iceland is 2-4°C colder than all of the last 8000 years except for a slightly colder late 19th century. Even the 1700s were warmer with less ice than today in and around Iceland.

A new study (Geirsdóttir et al., 2020) now affirms peak Holocene warmth at  least “∼3–4 °C above modern in Iceland” prevailed throughout much of the last 8000 years. Data from tree growth, glacier-induced soil erosion, algae productivity, sea ice biomarker proxies (IP25), and other climate indices affirm these conclusions.

The paper itself, ÁslaugGeirsdóttiraDavid J.HarningbGifford H.MillerbcJohn T.AndrewsbYafangZhongdChrisCaseldinee , "Holocene history of landscape instability in Iceland: Can we deconvolve the impacts of climate, volcanism and human activity?"

Landscape sensitivity to climate further intensified at ∼1.5 ka BP as identified by regime shift analysis. Hence, widespread and irreversible soil erosion began several centuries before the acknowledged settlement of Iceland, with a second acceleration ∼1250 CE. 

Something that cannot be blamed on those funloving Vikings,