Holocene climate change and its context for the future

Abstract

pose a major challenge for reconstructing annual temperatures and comparing unlike datasets (e.g. Mix 2006), particularly during the Holocene when seasonal insolation changes were strong compared to other forcings that act across the year. Model simulations are likewise challenged by initiating glacial inceptions from insolation forcing and are limited by some weakly constrained forcing inputs, such as volcanic and solar activity. r esolving the Holocene temperature conundrum is important for understanding the forcing-response mechanisms during the current interglacial and for putting present and future climate into context, as the global temperature trend dictates to what extent today’s earth system has already exited the Holocene range (Fig. 1b). Variability Temperature, precipitation, and glacier variability at sub-millennial frequencies and in multiple regions was also discussed. Given the relatively small changes in climate during the Holocene, differentiating a meaningful climate signal from proxy or local noise was highlighted as a critical goal for accurately reconstructing Holocene variability. This issue is central to comparisons between data and model results, which currently disagree over the spectrum of regional variability. Models tend to suppress the regional-scale variability seen by proxies at multi-decadal and longer periods (Fig. 1c). This discrepancy suggests that models may not generate enough low frequency internal variability, thus limiting their ability to produce accurate simulations of climate at longer time scales (Laepple and Huybers 2014).