> > > Among them, cloud feedbacks,
> >
> > http://www.grida.no/climate/ipcc_tar/wg1/271.htm
> > The potential complexity of the response of clouds to climate change
> > was identified in the SAR as a major source of uncertainty for climate
> > models. Although there has been clear progress in the physical content
> > of the models, ****clouds remain a dominant source of uncertainty*****,
> > because of the large variety of interactive processes which contribute
> > to cloud formation or cloud-radiation interaction: dynamical forcing
> > - large-scale or sub-grid scale, microphysical processes controlling
> > the growth and phase of the various hydrometeors, complex geometry with
> > possible overlapping of cloud layers. Most of these processes are
> > sub-grid scale, and need to be parametrized in climate models.
> Source of uncertainty, yes. But this merely disproves your assertion that
> clouds are ignored in models. It also does not support your contention that
> clouds as a whole are a negative feedback.
Is included incorrectly really an improvement on not included?
Clouds at our current temperature range are not a predominantly
negative feedback, however, at higher temperatures, the increased
albedo causes a strongly negative feedback.
One of the things that REALLY bothers me about the gcms is that
even if they were fully described for the current conditions, as the
temperature rises, this might as well be a different planet, the carbon
cycle will change, the weather patterns will change, and next to
nothing is known about the nature of the changes.
> > > surface level albedo changes,
> > http://www.grida.no/climate/ipcc_tar/wg1/291.htm
> > At present, only limited global data sets for LSPs are available and
> > these need to be further improved. A comprehensive land-use/land cover
> > data set, providing a global time-series of vegetation and soil
> > parameters over the last two centuries at GCM resolution, would be a
> > very useful tool to separate land-use change impacts on regional
> > climate from global scale warming effects. Additionally, for both
> > historical analyses and future projections, there is a need for
> > interactive vegetation models that can simulate changes in vegetation
> > parameters and carbon cycle variables in response to climate change.
> > These proposed fourth generation models are just beginning to be
> > designed and implemented within climate models.
> Shortcomings and room for improvement, yes. But this merely disproves your
> assertion that surface level albedo changes are ignored in models. Where is
> your evidence that surface level albedo changes are a negative feedback?
"limited datasets" is your idea of inclusion? again, including it
wrong isn't really much of an improvement in my view. And if you'd
read the link, you'd have seen that the researchers were predicting
predominantly negative effects from albedo changes. Additionally,
increased ocean area produces significantly higher albedos.
> > > solar variations,
> > http://www.grida.no/climate/ipcc_tar/wg1/244.htm
> > > long term cycles of all stripes,
> > http://www.grida.no/climate/ipcc_tar/wg1/025.htm#e3
> > As can be seen, there is a wide range of global scale internal
> > variability in these models.
> Again, nothing here to support your claims.
The wide range of model results indicates that these are not
understood and that which isn't understood cannot be included. you'd
see it if you'd clicked the link.
> > > methane release due to melting permafrost,
> > 4.5.3 Feedbacks through Natural Emissions
> > Natural emissions of N2O and CH4 are currently the dominant
> > contributors to their respective atmospheric burdens, with terrestrial
> > emissions greatest in the tropics. Emissions of both of these gases are
> > clearly driven by changes in physical climate as seen in the ice-core
> > record (Figure 4.1e). Soil N2O emissions are sensitive to temperature
> > and soil moisture and changes in rates of carbon and nitrogen cycling
> > (Prinn et al., 1999). Similarly, methane emissions from wetlands are
> > sensitive to the extent of inundation, temperature rise, and changes in
> > rates of carbon and nitrogen cycling. Natural emissions of the
> > pollutants NOx, CO, and VOC play an important role in production of
> > tropospheric O3 and the abundance of OH; and these emissions are
> > subject to similar forcings by both the physical and chemical climates.
> > Terrestrial and aquatic ecosystems in turn respond to near-surface
> > pollution (O3, NO2, acidic gases and aerosols) and to inadvertent
> > fertilisation through deposition of reactive nitrogen (often emitted
> > from the biosphere as NO or NH3). This response can take the form of
> > die back, reduced growth, or changed species composition competition
> > that may alter trace gas surface exchange and ecosystem health and
> > function. The coupling of this feedback system - between build-up of
> > greenhouse gases, human-induced climate change, ecosystem responses,
> > trace gas exchange at the surface, and back to atmospheric composition
> > -*****has not been evaluated in this assessment*****. The variety and
> > complexity of these feedbacks relating to ecosystems, beyond simple
> > increases with rising temperatures and changing precipitation, argues
> > strongly for the full interactive coupling of biogeochemical models of
> > trace gas emissions with chemistry and climate models.
>
> This is true, and I have a similar desire to see these things treated more
> thouroughly. But as you acknowledge this can only make things worse, and
> potentially much worse.
yes.
> > > and the
> > > absolutely stupid ghg value that is used for long term methane (it has
> > > an atmospheric half life of 1-2 years, after which it decomposes into
> > > CO2 and water, the stupidity is that in most climate modeling, they
> > > pretend that the water stays in the atmosphere, as though it were
> > > separate water not subject to rain)
> > I am sure that methane has a 500 year gwp of 6 if you keep all the
> > reaction products in the same test tube, however, in the atmosphere, it
> > has a 500 year (and in fact a 50 year) gwp of 1.
> And this relates to your claim that models don't account for rain how?
My claim wasn't that the models don't account for the evaporation
cycle, it was that they don't account for it's effect on the GWP of
methane. Adding atmospheric water doesn't produce any noticeable
greenhouse effect, so pretending that the water formed by the
decomposition of methane fails to rain out and including it in the long
term GWP of methane is simply stupid.
Here's a list of mammals that lived quite well in the eocene (the
last time the temperature of earth was 22 degrees C for extended
periods.
http://en.wikipedia.org/wiki/Category:Eocene_mammals
You seem to be laboring under the misaprehension that I am one of
the deniers or something. If anyhing, I am somewhere between alarmist
and fatalist. Do statements like "it's going to take everything we've
got to deal with the effects" and "we're going back to cretatious
conditions" and "start building refugee cities" really sound like an
AGW denier to you?
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