CRU : Projects : SO&P

SO&P: Project Summary

European Commission contract number: EVK2-CT-2002-00160 SOAP

SO&P is a research project funded by the European Union and led by Tim Osborn and Keith Briffa at UEA's Climatic Research Unit. The project will simulate the climate of the last 500 years, will develop improved reconstructions of the real climate over this period, and will compare the two to provide an important test of the climate models and an improved estimate of natural climate variability. This work will then be used to better quantify the uncertainty in future climate projections, and to re-assess the detection of unusual climate change in the observations.

Problems to be solved

This project will establish the capability of state-of-the-art European climate models to simulate the changes that have occurred in climate during the last five centuries. The ultimate aims of the work are: to establish the credibility of future climate estimates based on the models and to reexamine the question of how much of the recent large-scale warming observed in instrumental data is attributable to natural variability and how much is the result of anthropogenic modification of the terrestrial and atmospheric environment.

Scientific objectives and approach

The specific objectives are summarised as follows:
  1. To use observational and reconstructed climate, and climate simulations under historical external forcing, to evaluate the reliability of state-of-the-art climate models that are currently used in climate change signal detection studies and for future climate predictions.
  2. To analyse simulated climate variations for the period AD 1500-2000 using two advanced climate models forced with natural (volcanic aerosols, solar irradiance and orbital changes) and combined natural and anthropogenic (greenhouse gases, ozone, and sulphate aerosols) forcings.
  3. To provide improved regional estimates of the natural variability of climate on annual, decadal, and century time scales over the last 500 years, based on a new compendium and calibration of instrumental, documentary and palaeoclimate records.
The approach involves using two coupled climate models to simulate climate variations from A.D. 1500-2000, using natural and also combined natural/anthropogenic forcing. The climate responses to external forcings will be distinguished through comparison of the results with long control simulation experiments. The simulations will also be compared with evidence of past climate variability produced by amalgamating instrumental and annually-resolved palaeoclimate proxy data covering much of the Northern Hemisphere and tropics. Signal detection techniques will be used with the proxy data to search for the large-scale simulated response to external forcing and the proxy and model data will be merged to obtain improved estimates of natural variability that will be used in the reassessment of climate change detection. The project will also investigate the agreement between the observational (including proxy) and simulated variability in a number of temperature and precipitation variables; other important climate indices; the statistics of extreme events, and selected regional changes in sea level.

Expected impacts

We are concerned to improve our knowledge of natural climate variability and assess climate model reliability at decadal to century timescales so that we are better able to define the uncertainty in climate predictions made using two important models. Without such work we will be unable to assess the relative importance of natural and anthropogenic influences on recent past and likely future climates.

The users of our results include palaeoclimate researchers, scientists studying and testing models and processes of sub-components of the climate system and a variety of climate change impacts researchers. The improved palaeoclimate reconstruction generated will spawn numerous possibilities for additional research in palaeoclimatology and ecosystem studies.

Last updated: November 2002, Mike Salmon