Leafy moss dated to the Medieval Warm Period (MWP) has been found embedded in Antarctic glacier ice that today is “permanently snow-covered” with “no evidence of meltwater.” This affirms a warmer MWP and that “the summer melt during the MWP was greater than today.”
According to a new study, moss samples with intact leaves and stems 10 to 13 mm long have been discovered embedded in glacier ice – the Boulder Clay Glacier (BCG) – in Antarctica’s Victoria Land.
The surface of this glacier is currently not undergoing melt. It is instead permanently snow-covered.
“It is also noteworthy that under current climate conditions…there is no evidence of meltwater on the BCG, and the surface of the glacier is permanently snow-covered.”
The leafy moss samples have been dated to about 1,000 years ago, which is consistent with the timing of the Medieval Warm Period.
“…an unprecedented palaeo-erosion event occurred on the surface of an Anarctic glacier (northern Victoria Land, continental Antarctica) during the Medieval Warm Period (MWP) between 900 and 989 cal BP.”
“The period between 831 and 1140 cal BP is characterized by reduced sea ice in northern Victoria Land, which is consistent with the occurrence of a brief event of warmer conditions around 1000 cal BP…”
The presence of thousand-year-old plant remains in a modern glacier strongly suggest the climate was warmer (and thus there was less glacier ice) during the Medieval Warm Period.
“Further support for the occurrence of this short warming period was provided by the largest uplift event for the frost mound in the lake…observed only a few hundred metres from borehole B1 and dated between 790 and 1070 cal BP. Therefore, the past frost mound uplift documented at BCG may indicate that the summer melt during the MWP was greater than today.”
The warmth during the Medieval Warm Period has been suggested to be driven by ENSO, which is linked to solar activity. In other words, greenhouse gas concentrations played no identifiable role in this “huge warm pulse event.”
“The MWP in Victoria Land has been reported to be mainly driven by the El Niño Southern Oscillation (ENSO), which is linked to changes in solar activity through non-linear dynamics.”
Well well news for some: In other words, greenhouse gas concentrations played no identifiable role in this “huge warm pulse event.”
I recognize that plant.
It came from my garden.
Shit – it was a really hot summer, so I moved to a cooler continent.
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