Second, they took a second set
of climate model simulations which were identical to the first set, except that CO2 concentrations were kept constant at 19th century levels.
This would not only improve the
accuracy of the climate model forecasts but would provide a basis for computing the uncertainty which applies to each forecast.
However, it is concluded that these new results can eventually improve the
ability of climate models to better predict future precipitation changes.
We were able to quantify the internal variability contribution using an unprecedented large
set of climate model simulations.
Also included in the figure (black circles) is the average trend in surface temperatures produced by a
collection of climate models for the same intervals.
First, they took the global temperature results from one set
of climate models which incorporated the known changes in CO2.
Before making expensive policy decisions on the
basis of climate models, I think it is reasonable to require that those models predict future temperatures accurately for a period of ten years.
We'll likely revisit this topic, as it is a long - standing critique from climate skeptics and an important
test of climate models.
There is yet little confidence in this feedback
component of climate models and therefore its possible contribution to global warming (see Chapter 8).
First realize that the consensus that CO2 has driven recent climate change is based on the
inability of climate models to detect natural variability associated with recent changes.
We now have reached the point where you agree that parameter estimation is
part of climate models, and now statistical inference is too.
Saying that a map doesn't capture the true landscape or a portrait the true self is very confusing as a lead - in to a
discussion of climate models.
Very warm springs have been anomalies, but this new
analysis of climate model data shows an increased frequency to nearly one in every three years by the end of this century.
In this portion of the film, the professor is speaking about the
complexity of climate models and how their results can be greatly influenced by the input data they are given.
In the
case of the climate model projections the projections start from a known value so there can be no error for the starting point.
It also acts as an advisory group / think tank to identify priorities and research and investment needs in the
field of climate modelling and services.