IPCC Climate Change Data: CGCM1 A2a Model: 2080 Minimum Temperature

The first version of the Canadian Global Coupled Model,
CGCM1, and its control climate are described by Flato et al.
(1999). The atmospheric component of the model is essentially
GCMII described by McFarlane et al. (1992). It is a spectral
model with triangular truncation at wave number 32 (yielding a
surface grid resolution of roughly 3.7 degrees x3.7 degrees) and
10 vertical levels. The ocean component is based on the GFDL
MOM1.1 code and has a resolution of approximately 1.8 degrees
x1.8 degrees and 29 vertical levels. The model uses heat and
water flux adjustments obtained from uncoupled ocean and
atmosphere model runs (of 10 years and 4000 years duration
respectively), followed by an `adaption' procedure in which the
flux adjustment fields are modified by a 14 year integration of
the coupled model. A multi-century control simulation with the
coupled model has been performed using the present-day CO2
concentration to evaluate the stability of the coupled model's
climate, and to compare the modelled climate and its variability
to that observed. An ensemble of four transient climate change
simulations has been performed and is described in Boer et al.
(1999a; b). Three of these simulations use an effective
greenhouse gas forcing change corresponding to that observed
from 1850 to the present, and a forcing change corresponding to
an increase of CO2 at a rate of 1% per year (compounded)
thereafter until year 2100. The direct forcing effect of
sulphate aerosols is also included by increasing the surface
albedo (as in Reader and Boer, 1999) based on loadings from the
sulphur cycle model of Langner and Rodhe (1991). The fourth
simulation considers the effect of greenhouse gas forcing only.
The change in climate predicted by a model clearly depends
directly on this specification of greenhouse gas (and aerosol)
forcing, and of course these are not well known. The
prescription described above is similar to the IPCC
"business as usual" scenario, and using a standard
scenario allows the results of this model to be compared to
those of other modelling groups around the world. Some initial
results from these simulations are presented below. The climate
sensitivity of CGCM1 is about 3.5 degrees C. For the A2
emissions scenario the main emphasis is on a strengthening of
regional and local culture, with a return to family values in
many regions. The A2 world consolidates into a series of roughly
continental economic regions, emphasizing local cultural roots.
In some regions, increased religious participation leads many to
reject a materialist path and to focus attention on contributing
to the local community. Elsewhere, the trend is towards ncreased
investment in education and science and growth in economic
productivity. Social and political structures diversify with
some regions moving towards stronger welfare systems and reduced
income inequality, while others move towards "lean"
government. Environmental concerns are relatively weak, although
some attention is paid to bringing local pollution under control
and maintaining local environmental amenities. The A2 world sees
more international tensions and less cooperation than in A1 or
B1. People, ideas and capital are less mobile so that technology
diffuses slowly. International disparities in productivity, and
hence income per capita, are maintained or increased. With the
emphasis on family and community life, fertility rates decline
only slowly, although they vary among regions. Hence, this
scenario family has high population growth (to 15 billion by2100) with comparatively low incomes per capita relative to the
A1 andB1 worlds, at US$7,200 in 2050 and US$16,000 in
2100.Technological change is rapid in some regions and slow in
others as industry adjusts to local resource endowments,
culture, and education levels. Regions with abundant energy and
mineral resources evolve more resource intensive economies,
while those poor in resources place very high priority on
minimizing import dependence through technological innovation to
improve resource efficiency and make use of substitute inputs.
The fuel mix in different regions is determined primarily by
resource availability. And divisions among regions persist in
terms of their mix of technologies, with high-income but
resource-poor regions shifting toward advanced post fossil
technologies (renewables in regions of large land availability,
nuclear in densely populated, resource poor regions) and
low-income resource-rich regions generally relying on older
fossil technologies.With substantial food requirements,
agricultural productivity is one of the main focus areas for
innovation and RD efforts in this future. Initially high levels
of soil erosion and water pollution are eventually eased through
the local development of more sustainable high-yield
agriculture.Although attention is given to potential local and
regional environmental damage, it is not uniform across regions.
For example, sulfur and particulate emissions are reduced in
Asia due to impacts on human health and agricultural production
but increase in Africa as a result of the intensified
exploitation of coal and other mineral resources. The A2 world
sees high energy and carbon intensity, and correspondingly high
GHG emissions. Its CO2 emissions are the highest of all four
scenario families. Data are available for the following
periods: 1961-1990, 2010-2039; 2040-2069; and 2090-2099, mean
and monthly change fields.