Reconstructing mid- to high-latitude marine climate and ocean variability using bivalves, coralline algae, and marine sediment cores from the Northern Hemisphere

Quantifying the role and contribution of the world's oceans in past, present, and future global change is an essential goal in climate, paleoclimate and environmental studies. Although the global oceans interact and influence climate greatly, the marine environment is substantially under-represented in key climate assessment reports, especially during the last millennium (IPCC, 2007; see Palaeoclimate chapter: 6.6—The last 2000 years). The under-representation of marine records in key climate documents likely results from the often imprecise chronologies associated with many marine-based archives, which greatly hinders singular climate comparisons (lag/lead phasing relationships) with well-dated, and/or annually-resolved archives. However, several marine archive records have excellent chronological constraint. In particular, many marine bivalve taxa and coralline algae have annual increments that form within their carbonate framework, that can be used to establish an absolutely-dated chronology, via cross-dating techniques, from the marine environment. Additionally, in some cases, where sedimentation rates are high, and alternative chronological dating methods exist (e.g., tephrochronology) other than radiocarbon measurements (often greater than ± 40 years uncertainty), sediment archives can provide continuous, sub-decadal records of environmental change for centuries to millennia. This brief introductory article and accompanying special issue will focus on the utilization of bivalves, coralline algae, and high-resolution marine sediment cores in paleoclimate and environmental studies within the most recent millennium with a focus on the Northern Hemisphere.