«A cloud system - resolved model can reduce one of
the greatest uncertainties in climate models, by improving the way we treat clouds,» Wehner said.
Not exact matches
Although there is still some disagreement
in the preliminary results (eg the description of polar ice caps), a lot of things appear to be quite robust as the
climate models for instance indicate consistent patterns of surface warming and rainfall trends: the
models tend to agree on a stronger warming
in the Arctic and stronger precipitation changes
in the Topics (see crude examples for the SRES A1b scenarios given
in Figures 1 & 2; Note, the degrees of freedom varies with latitude, so that the
uncertainty of these estimates are
greater near the poles).
The aerosol forcing is the biggest tuning
in this regard
in many
climate models, although the GISS
model uses published forward calculations (the right thing to do, but still fraught with
great uncertainty), whereas many
climate models use an inverse method to get aerosol forcing that matches.
If one uses the historical record of warming to help tune your
climate model, you are assuming that 100 % of warming is due to the forcing we know about (with a
great deal of
uncertainty in the case of aerosols).
«The assessment is supported additionally by a complementary analysis
in which the parameters of an Earth System
Model of Intermediate Complexity (EMIC) were constrained using observations of near - surface temperature and ocean heat content, as well as prior information on the magnitudes of forcings, and which concluded that GHGs have caused 0.6 °C to 1.1 °C (5 to 95 % uncertainty) warming since the mid-20th century (Huber and Knutti, 2011); an analysis by Wigley and Santer (2013), who used an energy balance model and RF and climate sensitivity estimates from AR4, and they concluded that there was about a 93 % chance that GHGs caused a warming greater than observed over the 1950 — 2005 period; and earlier detection and attribution studies assessed in the AR4 (Hegerl et al., 2007b).&r
Model of Intermediate Complexity (EMIC) were constrained using observations of near - surface temperature and ocean heat content, as well as prior information on the magnitudes of forcings, and which concluded that GHGs have caused 0.6 °C to 1.1 °C (5 to 95 %
uncertainty) warming since the mid-20th century (Huber and Knutti, 2011); an analysis by Wigley and Santer (2013), who used an energy balance
model and RF and climate sensitivity estimates from AR4, and they concluded that there was about a 93 % chance that GHGs caused a warming greater than observed over the 1950 — 2005 period; and earlier detection and attribution studies assessed in the AR4 (Hegerl et al., 2007b).&r
model and RF and
climate sensitivity estimates from AR4, and they concluded that there was about a 93 % chance that GHGs caused a warming
greater than observed over the 1950 — 2005 period; and earlier detection and attribution studies assessed
in the AR4 (Hegerl et al., 2007b).»
This should,
in theory, lead to more realistic projections for the future, but many of the
climate modellers I spoke to were keen to point out that simulating the
climate with more complex
models may well lead to
greater uncertainty about what the future holds.
The
uncertainties in global
climate models vs empirical observations are equally
great ranging from 10 C by 2100!