Climate change is now recognised internationally as a major issue affecting all nation states. Policymakers require reliable climate-modelling scenarios to determine effective strategies for economic development. However, climate 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 proxy-climate sources imply there were abrupt climate changes in the mid-late Holocene that had significant effects on human societies in Europe and elsewhere. Hitherto under-used primary proxy-climate data sources in Europe are mires and lakes. Mires in northern Europe provide excellent multi-proxy data on past climates, having robust replicable records with decadal resolution. Their stratigraphy notably defines episodes of abrupt climate change; further south in Europe, these climate shifts can also be defined by major lake-level changes. This project will generate continuous records of proxy-climate data from mire sites in transects across Europe, and compare with complementary data on lake-level changes, to focus on episodes of past abrupt climate change. The project will generate a pan-European perspective on climate changes of the past 4500 years, and through study of mire carbon-balance an asssessment of the 'Global Warming Potential' over that period. The benefits include a much clearer perspective on the magnitude, rate, frequency, causes and effects of past climate change in Europe.
ACCROTELM will refine and apply existing
techniques of plant macrofossil and peat humification analysis
to peat cores; it will use testate amoebae as a pan-European climate
proxy; it will explore development of a new biomolecular temperature
proxy; and it will quantify carbon balance. The project will produce
continuous proxy-climate data for the last 4500 years from mire
sites on transects -
(i) E-W across Europe,
(ii) N-S in west-central Europe to link with lake-level change
data, and
(iii) on the Atlantic fringe,
in order to define abrupt climate changes in Europe and their
relationship with forcing factors. Detailed, high-precision multi-proxy
analyses will concentrate on times of abrupt climate change, to
assess the causes, rate, magnitude and effects of climate shifts.
Results will be synthesised for dissemination to end-users, notably:
(i) modellers, for use to test and refine models of European climate;
and
(ii) policymakers.
At the end of the project a more complete picture will be available
of the rate, magnitude and frequency of past climate change over
the past 4500 years in Europe, and the relationship of these to
mire carbon balance.
Peat deposits have long been recognised as sources of proxy-climate data, but their excellent potential in this respect has not been properly or fully utilised. This is now recognised internationally in the recent designation by PAGES (PAst Global changES) of a 'Europeat' initiative. However, even though peat-bog data from north-west Europe point to abrupt natural changes in European climate in the mid- and late Holocene, such valuable information has not been collected in any systematic funded pan-European programme. ACCROTELM will provide data on Holocene climate change in Europe, so as to understand better the rates, magnitude and frequencies of natural climate change. The project will generate records from terrestrial sites more adjacent to human habitation than data derived from ice-cores or oceanic sediments, and so will create a multi-proxy database of the climate changes that have affected the land mass of the EC and adjacent states. The degree of natural climate change within the Late Holocene, as indicated by these proxy-climate records, will form a baseline that can be compared with the instrumental data from meteorological records. Without a full knowledge of past climates, it is impossible to distinguish between natural and human-induced components of recent climate change, and erroneous future climate scenarios may be produced. This project will therefore inform climate modellers of the extent and rate of past natural climate changes across Europe, so that they may integrate such data into their modelling capability, enabling the generation of more reliable future climate scenarios for policymakers.