Paper: Davies-Barnard et al 2017

Title: Quantifying the Influence of the Terrestrial Biosphere on Glacial-interglacial Climate Dynamics

For a fuller description of the paper itself, go to the end of this web page.

Each simulation published in this paper corresponds to a unique 5 or 6 character code on the web pages.
The following table lists the name of the simulation as used in the paper, and the corresponding code name

The webpage gives you the ability to examine the published simulations, but you can also download the raw (netcdf) files to perform your own analysis. Detailed instructions on how to use the webpages and access the data can be found here: Using_BRIDGE_webpages.pdf

There are two sequences of 62 simulations that both cover 120 kyr, one set with fixed vegetation, one with dynamic vegetation.

You can have make you own analysis and plots by going here

Name of sequence of simulations as in PaperSimulation sequence name as in web pagesDetailed description of individual simulations within sequence
Static - Sequence of simulations with vegetation fixed as Pre-industrialbbc_all_triff_rev_statDetailed List of Runs
Dynamic - Sequence of simulations using with dynamic vegetationbbc_all_triff_rev_dynDetailed List of Runs


This is a fuller description of paper

This paper is the first model analysis using a fully-coupled dynamic atmosphere-ocean-vegetation GCM over the last 120 ka that quantifies the net effect of vegetation on climate. This analysis shows that over the whole period the biogeophysical is the dominant effect, and that the biogeochemical impacts may have a lower possible range than typically estimated.

NameDavies-Barnard et al.
Brief DescriptionThis paper is the first model analysis using a fully-coupled dynamic atmosphere-ocean-vegetation GCM over the last 120 ka that quantifies the net effect of vegetation on climate. This analysis shows that over the whole period the biogeophysical is the dominant effect, and that the biogeochemical impacts may have a lower possible range than typically estimated.
Full Author ListDavies-Barnard T., Ridgwell A., Singarayer J. S., and Valdes P. J.
TitleQuantifying the Influence of the Terrestrial Biosphere on Glacial-interglacial Climate Dynamics
Year2017
JournalClimate of the Past
Volume
Issue
Pages
DOI
Contact's NameT Davies-Barnard
Contact's emailt.davies-barnard@bristol.ac.uk
AbstractThe terrestrial biosphere is thought to be a key component in the climatic variability seen in the paleo record. It has a direct impact on surface temperature through changes in surface albedo and evapotranspiration (so called biogeophysical effects) and in addition, has an important indirect effect through changes in vegetation and soil carbon storage (biogeochemical effects) and hence modulates the concentrations of greenhouse gases in the atmosphere. The biogeochemical and biogeophysical effects generally have opposite signs meaning that the terrestrial biosphere could potentially have played only a very minor role in the dynamics of the glacial-interglacial cycles of the late Quaternary. Here we generate and analyse a set of simulations spanning the last 120 ka using a fully coupled dynamic atmosphere-ocean-vegetation General Circulation Model (GCM) and thereby elucidate the relative importance of biogeophysical versus biogeochemical interactions of the terrestrial biosphere with climate. We find that the biogeophysical effects of vegetation account for up to an additional -0.84$^{\circ} global mean cooling, with regional cooling as large as -5$^{\circ}, but with considerable variability across the glacial-interglacial cycle. By comparison, while opposite in sign, our model estimates of the biogeochemical impacts are substantially smaller in magnitude. Offline simulations show a maximum of +0.33$^{\circ} warming due an increase of 25 ppm above our (pre-industrial) baseline atmospheric CO$ mixing ratio. In contrast to shorter (century) time-scale projections of future terrestrial biosphere response where direct and indirect responses may at times, cancel out, we find that the biogeophysical effects consistently and strongly dominate the biogeochemical over the inter-glacial cycle. In addition, depending on the assumptions about soil carbon under ice-sheets and sea level rise, we find a range in terrestrial carbon storage change from a reduction in LGM carbon storage of -440 PgC, to a gain of +37 PgC. We suggest that prevailing uncertainties allow for only a small net transfer of carbon between terrestrial biosphere and ocean atmosphere implying that explaining the observed CO$ ice core record could be rather simpler than previously thought.