Deliverable D4/5: Global climatic characteristics, including vegetation and seasonal cycles over Europe, for snapshots over the next 200,000 years. Work Package 2, Simulation of the future evolution of the biosphere system using the hierarchical strategy. Modelling Sequential Biosphere Systems under Climate Change for Radioactive Waste Disposal (BIOCLIM)

Abstract

The aim of the BIOCLIM project is to develop and
present techniques that can be used to develop
self-consistent patterns of possible future
climate changes over the next million years (climate
scenarios), and to demonstrate how these climate
scenarios can be used in assessments of the long-term
safety of nuclear waste repository sites.
Within the project, two strategies are implemented to
predict climate change. The first is the hierarchical
strategy, in which a hierarchy of climate models is used
to investigate the evolution of climate over the period of
interest. These models vary from very simple 2-D and
threshold models, which simulate interactions between
only a few aspects of the earth system, through general
circulation models (GCMs) and vegetation models,
which simulate in great detail the dynamics and physics
of the atmosphere, ocean, and biosphere, to regional
models, which focus in particular on the European
region and the specific areas of interest. The second
strategy is the integrated strategy, in which
intermediate complexity climate models are developed,
and used to consecutively simulate the development of
the earth system over many millennia. Although these
models are relatively simple compared to a GCM, they
are more advanced than 2D models, and do include
physical descriptions of the biosphere, cryosphere,
atmosphere and ocean.
This deliverable, D4/5, focuses on the hierarchical
strategy, and in particular the GCM and vegetation
model simulation of possible future climates.
Deliverable D3 documented the first step in this
strategy. The Louvain-la-Neuve 2-D climate model
(LLN-2D) was used to estimate (among other variables)
annual mean temperatures and ice volume in the
Northern Hemisphere over the next 1 million years.
It was driven by the calculated evolution of orbital
parameters, and plausible scenarios of CO2
concentration. From the results, 3 future time periods
within the next 200,000 years were identified as being
extreme, that is either significantly warmer or cooler
than the present. The next stage in the hierarchical
strategy was to use a GCM and biosphere model, to
simulate in more detail these extreme time periods.