CO 2-sensitivity experiments using general circulation models

Abstract

According to Lorenz (1975) we can distinguish two types of climate prediction: predictability of the first kind, i.e. the long-range evolution of climate under constant boundary conditions in dependence on the initial climatic state, and predictability of the second kind, i.e. the assessment of the equilibrium response of the climate system to a prescribed change in external influences. With the first type climatic factors can be predicted for millions of years which would be of interest in the study e.g. of ice ages. With the second kind the response of the the observed temperature and precipitation data plus the model-generated data, and

Assessing the sensitivity of Canada's ecosystems to climatic change

“…The data, originally at a spatial resolution of 8 ~ longitude by 10 ~ latitude, was subsequently modified by Bach (1984) to a 4 ~ longitude by 5 ~ latitude grid to enhance the spatial resolution. With this modification there were 180 data points covering Canada.…”

Impacts of GISS-modelled climate changes on catchment hydrology

“…CH 4 , N 2 0, CFC-11, CFC-12) by about 20% over the last hundred years (US National Academy of Sciences, 1983;Jager, 1983;USEPA, 1983;Bach, 1984;Palutikof et al, 1984;Houghton, 1991;Siegenthaler & Sanhueza, 1991). It is expected that, during the next fifty to eighty years (until 2070), those activities will result in doubling the concentration of C0 2 in the atmosphere (US National Academy of Sciences, 1983;Manabe & Wetherald 1985;MacCracken & Luther 1986;Mitchell & Qingcun, 1991) and, through a "greenhouse" effect, cause a gradual warming of the Earth.…”

“…However, the spatial scale of GCM outputs is inadequate for catchment hydrological simulation. The GCM predictions are provided as spatial averages over areas of the order of 10 4 to 10 5 km 2 (macro-scale), where the fundamental differential equations of the continuum hydro-and thermodynamics can conserve a real-world validity in contrast to the validity of these equations when they are applied to the hydrological modelling of a catchment (meso-and micro-scale simulation) (Becker & Nëmec, 1987). Furthermore, it is doubtful if GCM predictions on time scales shorter than one month reflect the natural variability of field data, because such predictions represent grid-cell averages.…”