Abstract
Accelerated Arctic warming and wetting has global impacts, as the region`s glaciers and ice caps respond to changes in temperature (melt) and precipitation (growth), driving on-going sea-level change. However, as the observations needed to calibrate models are scarce and uncertain, predictions cannot confirm if future increases in snowfall can counterbalance ice loss. To help answer this key question, we present evidence of Arctic glacier survival throughout the warmer-than-present Holocene Thermal Maximum (HTM). For this purpose, we analyzed 14 ka long sediment records from two glacial lakes – continuous recorders of past glacier change, fed by Åsgardfonna – an ice cap that survived HTM heat based on mass balance simulations, on Svalbard – a climate change hotspot characterized by the region`s highest rates of warming, sea ice loss, and precipitation change. End Member Modelling Analysis (EMMA) allows us to unmix the diluted diagnostic grain size signal of rock flour – a widely used proxy for past glacier change, and surface runoff – an indicator of hydrological intensification. These reconstructions reveal that Åsgardfonna even advanced under HTM conditions because seasonal sea-ice loss enhanced snowfall. Our findings thus suggest that the near-future retreat and sea-level contribution of Arctic glaciers and ice caps might be slower than assumed.