• Energy Research

The discovery of more than 600 whole and fragmentary engraved stone plaques in the early third millennium BC infill from the ditches of a causewayed enclosure at Vasagård, on the Danish island of Bornholm, represents a unique find in Neolithic miniature art. Termed ‘sun stones’ in reference to the rayed images that characterise many of the plaques, the stones were deposited en masse over a short period. This article offers a fundamental classification of the rich imagery captured in the engravings and examines its potential function at a time of possible climatic crisis that impacted not just Bornholm but the wider northern hemisphere.

AbstractThe mechanistic pathways connecting ocean-atmosphere variability and terrestrial productivity are well-established theoretically, but remain challenging to quantify empirically. Such quantification will greatly improve the assessment and prediction of changes in terrestrial carbon sequestration in response to dynamically induced climatic extremes. The jet stream latitude (JSL) over the North Atlantic-European domain provides a synthetic and robust physical framework that integrates climate variability not accounted for by atmospheric circulation patterns alone. Surface climate impacts of north-south summer JSL displacements are not uniform across Europe, but rather create a northwestern-southeastern dipole in forest productivity and radial-growth anomalies. Summer JSL variability over the eastern North Atlantic-European domain (5-40E) exerts the strongest impact on European beech, inducing anomalies of up to 30% in modelled gross primary productivity and 50% in radial tree growth. The net effects of JSL movements on terrestrial carbon fluxes depend on forest density, carbon stocks, and productivity imbalances across biogeographic regions.