A global perspective on the climate‐driven growth synchrony of neighbouring trees

2 .pdf files: File 1. Author's article final version, Post-Print (19 Pags.- 4 Figs.- 2 Tabls.). File 2. Supplementary Materials (3 Figs.- 2 Tabls.- 1 Model Equation).

The limits of freely-available tree-ring chronologies

The influence of decision-making in tree ring-based climate reconstructions.

Tree-ring chronologies underpin the majority of annually-resolved reconstructions of Common Era climate. However, they are derived using different datasets and techniques, the ramifications of which have hitherto been little explored. Here, we report the results of a double-blind experiment that yielded 15 Northern Hemisphere summer temperature reconstructions from a common network of regional tree-ring width datasets. Taken together as an ensemble, the Common Era reconstruction mean correlates with instrumental temperatures from 1794–2016 CE at 0.79 (p < 0.001), reveals summer cooling in the years following large volcanic eruptions, and exhibits strong warming since the 1980s. Differing in…

A 1200+ year reconstruction of temperature extremes for the northeastern Mediterranean region

Proxy evidence is necessary to place current temperature and hydroclimatic changes in a long-term context and to assess the full range of natural and anthropogenic climate forcings. Here, we presen ...

Large-scale, millennial-length temperature reconstructions from tree-rings

Supported by the German Science Foundation, grants # Inst 247/665-1 FUGG and ES 161/9-1. SSG acknowledges support by the Alexander von Humboldt Foundation, KJA by US National Science Foundation grants AGS-1501856 and NSF AGS-1501834, and JL and LS by the Belmont Forum and JPI-Climate, Collaborative Research Action INTEGRATE. Over the past two decades, the dendroclimate community has produced various annually resolved, warm season temperature reconstructions for the extratropical Northern Hemisphere. Here we compare these tree-ring based reconstructions back to 831 CE and present a set of basic metrics to provide guidance for non-specialists on their interpretation and use. We specifically d…

Warfare dendrochronology: Trees witness the deployment of the German battleship Tirpitz in Norway

Abstract War has an immediate and obvious effect on people and communities, but its impacts on local ecology can be more subtle. This paper shows how one military encounter in the Second World War has left a clear legacy in the northern forests of Norway, trackable more than seventy years later. We used annual growth rings of ∼180 pine and ∼30 birch trees as witnesses of the deployment of the German battleship Tirpitz at the Kafjord. The Tirpitz was the target of several Allied air attacks, but the Kriegsmarine (German navy from 1935 to 1945) used artificial smoke, consisting of chlorosulfonic acid and zinc/hexachloroethane, to hide the ship. These smoke-screen actions throughout 1944 cause…

The weight of the flood‐of‐record in flood frequency analysis

Concord and discord among Northern Hemisphere paleotemperature reconstructions from tree rings

Abstract We review the current generation of large-scale, millennial-length temperature reconstructions derived from tree rings and highlight areas of agreement and disagreement among these state-of-the-art paleotemperature estimates. Although thousands of tree ring-width chronologies are now available from temperate and boreal forest sites across the Northern Hemisphere, only a small fraction of those records are suited as proxies for surface temperature. Maximum latewood density is clearly a superior temperature proxy but is less available, with few densitometric records that are both long and up-to-date. Compared to previous efforts, the newest generation of tree-ring reconstructions cor…