ACCROTELM: the acronym is based on the division of diplotelmic
mires into two layers: the Acrotelm, the layer above the water
table where most decomposition and peat formation takes place
(which relates to recent peat accumulation over the period of
instrumental climate records), and the Catotelm [central 'C' in
the acronym], below the water table, where long proxy-climate
records, fundamental for evaluating the instrumental period, are
preserved . For this project, abrupt climate change is defined
as a directional pervasive shift in climate that occurs within
a human life-span (but excluding short-lived 2-3 year perturbations
caused for example by single volcanic eruptions).
European policymakers require reliable climate-modelling scenarios to determine effective strategies for economic development. However, models can only provide plausible scenarios for Europe if they are tested and validated against past climates. The frequency, magnitude and rate of past climate changes are incompletely known, but diverse sources imply there were abrupt climate changes in the mid-late Holocene that had significant effects on human societies in Europe and elsewhere. ACCROTELM will investigate some of these changes using the hitherto under-used primary proxy-climate data sources contained in mires.
Recent research has shown that mires provide excellent data on past abrupt climate changes. These data can be integrated with complementary climate data from lakes to demonstrate the magnitude and rate of Holocene climatic variability, for use in climate modelling. Mires have diverse proxy-climate indicators, with direct coupling to the atmosphere; robust, replicable records with decadal resolution; and circum-North Atlantic distribution. European mires and lakes yield integrated records of hydrological/temperature changes, directly referable to climate (rather than to 'weather' events). This project will produce new high-resolution data and from these assess evidence for climate variability across Europe during the past 4500 yr, thus providing analyses of abrupt climate changes and their effects. The research will combine the development and refinement of proven techniques with the innovative development of biomolecular technologies and testate amoebae proxies.
In this way ACCROTELM will generate continuous records of hydrological/temperature changes from mire sites in transects across Europe. These records will be compared with complementary summary data on lake-level changes, and will provide a focus on episodes of abrupt climate change. ACCROTELM will employ new methods to provide superior data and will assess the actual and potential scale of effects of abrupt climate change in Europe. These new insights will be used to inform future EU policy.
These pages maintained by John Daniell (last updated 1 March 2007)