Fig. 4: Plant biomarkers from NYA 17–154 core compared with Arctic sea ice extent and glaciers retreat over the last 780 years.
From: Greening of Svalbard in the twentieth century driven by sea ice loss and glaciers retreat

The lines show a the 40-year smoothed late-summer Arctic sea ice extent reconstructed from high-resolution terrestrial proxies20, b sum of cutin acids concentration, c ratio of C16 ω-hydroxy alkanoic acids to the sum of C16 ω-hydroxy alkanoic acids, DAs, and mid-chain hydroxy and epoxy acids (ω-C16/∑C16). d ratio of p-coumaric acid (pCd) to ferulic acid (Fd), e Lignin Phenol Vegetation Index (LPVI), and f proximal glacier foraminifera (C. reniforme and E. excavatum f. clavatum)31. The solid curves correspond to the generalized additive mode (GAM) trend, with light bands representing 95% across-the-function confidence intervals. The gray columns highlight the Little Ice Age (LIA) and its coldest phase (dark gray)154. The yellow areas display periods with low sea ice extent20.