Man Based Global Warming....

[thepolarcrew]

As for this "Milankovic cycle", is it also possible we are tipping to a new angle as the plates shift?

Not denying we might be (still gets colder than hell up here) warming, but that there are many things affecting this change not just man.

It's like we have returned a bit to how the weather was when I was really young, 40 yrs ago. No snow until after thanksgiving, then you get dumped on, freeze your tail off most of the winter, then get dumped on again in the early spring and then hotter than hell and a good rain or periods of after the 4th.

[Alric]

Originally Posted by dbermanmd

You guys are way too advanced on this subject for me. I am going to try and simplify this discussion.

Is it the hypothesis of those who believe in man based global warming that the main culprit behind this phenomenon is CO2 production? If not, what is or are its main driving influences?

Thanks in advance,,, and try to keep it as simple as possible.

This has been discussed previously. If you have a point why don't you simply express it.

[wxman]

In my opinion, the greatest source of uncertainty with respect to AGW is the General Circulation Models (GCMs – i.e., climate models) used for climate projections themselves. According to the IPCC, GCMs are essentially numerical weather prediction (NWP) models and I suspect somewhat simplified versions at that (presumably, it would take too long to run very sophisticated NWP models out years/decades).

I use NWP models (e.g., GFS, WRF, ECMWF, GEM, SREF, GEFS) on a daily basis (I’m an atmospheric scientist) and based on my experience, NWPs are virtually clueless after about a week (i.e., have no skill), never mind projecting decades in the future, even on the climate temporal scale and global spatial scale. I generally work in the mesoscale, but errors in the mesoscale will eventually affect the global scale. The atmosphere (troposphere) is simply too complex to model out to extended periods of time.

The biggest uncertainty with these models is their depiction of cloud cover. In my experience this is something that occurs from initialization. How anyone can actually expect these models to have any idea of what cloud cover will look like in a warmed climate is beyond me. IPCC does address this to some degree, suggesting the negative feedback from increased cloud cover could potentially offset the warming induced by anthropogenic greenhouse gases.

That being said, I’m also not prepared to call AGW “a crock” either. CO2 and other greenhouse gases do absorb IR – that’s not controversial. I think we simply don’t know what the effect will be, and we’re essentially conducting a vast experiment with our atmosphere. Thus, I think it’s prudent to limit emissions to the greatest degree practicable.

[thepolarcrew]

Originally Posted by wxman

In my opinion, the greatest source of uncertainty with respect to AGW is the General Circulation Models (GCMs – i.e., climate models) used for climate projections themselves. According to the IPCC, GCMs are essentially numerical weather prediction (NWP) models and I suspect somewhat simplified versions at that (presumably, it would take too long to run very sophisticated NWP models out years/decades).

I use NWP models (e.g., GFS, WRF, ECMWF, GEM, SREF, GEFS) on a daily basis (I’m an atmospheric scientist) and based on my experience, NWPs are virtually clueless after about a week (i.e., have no skill), never mind projecting decades in the future, even on the climate temporal scale and global spatial scale. I generally work in the mesoscale, but errors in the mesoscale will eventually affect the global scale. The atmosphere (troposphere) is simply too complex to model out to extended periods of time.

The biggest uncertainty with these models is their depiction of cloud cover. In my experience this is something that occurs from initialization. How anyone can actually expect these models to have any idea of what cloud cover will look like in a warmed climate is beyond me. IPCC does address this to some degree, suggesting the negative feedback from increased cloud cover could potentially offset the warming induced by anthropogenic greenhouse gases.

That being said, I’m also not prepared to call AGW “a crock” either. CO2 and other greenhouse gases do absorb IR – that’s not controversial. I think we simply don’t know what the effect will be, and we’re essentially conducting a vast experiment with our atmosphere. Thus, I think it’s prudent to limit emissions to the greatest degree practicable.

Do you work for the TVA?

So what you're saying is, now would be a Great time to execute some serious changes while people are actually thinking about change vs dragging them screaming into change.

The old guys are about gone and us older ones are still some what youngsters. Being born into the rocket, tech or what ever age you want to call it.

Still, some just hate change though.

[wxman]

Originally Posted by thepolarcrew

Do you work for the TVA?

No - but I do work for a federal agency (standard disclaimer - the opinions expressed here are mine and do not necessarily reflect those of the U.S. Government ).

So what you're saying is, now would be a Great time to execute some serious changes while people are actually thinking about change vs dragging them screaming into change.

Yup - I think it would be prudent to pursue technologies that decrease greenhouse gas emissions.

[thepolarcrew]

Originally Posted by wxman

No - but I do work for a federal agency (standard disclaimer - the opinions expressed here are mine and do not necessarily reflect those of the U.S. Government ).


Yup - I think it would be prudent to pursue technologies that decrease greenhouse gas emissions.

+1

Do you believe in clean coal? The university up here is working on it.

[wxman]

Originally Posted by thepolarcrew

+1

Do you believe in clean coal? The university up here is working on it.

Clean coal can be beneficial from a reduction-in-imported-oil perspective (e.g., CTL). However, it doesn't address greenhouse gas emission reductions.

[dbermanmd]

Originally Posted by wxman

In my opinion, the greatest source of uncertainty with respect to AGW is the General Circulation Models (GCMs – i.e., climate models) used for climate projections themselves. According to the IPCC, GCMs are essentially numerical weather prediction (NWP) models and I suspect somewhat simplified versions at that (presumably, it would take too long to run very sophisticated NWP models out years/decades).

I use NWP models (e.g., GFS, WRF, ECMWF, GEM, SREF, GEFS) on a daily basis (I’m an atmospheric scientist) and based on my experience, NWPs are virtually clueless after about a week (i.e., have no skill), never mind projecting decades in the future, even on the climate temporal scale and global spatial scale. I generally work in the mesoscale, but errors in the mesoscale will eventually affect the global scale. The atmosphere (troposphere) is simply too complex to model out to extended periods of time.

The biggest uncertainty with these models is their depiction of cloud cover. In my experience this is something that occurs from initialization. How anyone can actually expect these models to have any idea of what cloud cover will look like in a warmed climate is beyond me. IPCC does address this to some degree, suggesting the negative feedback from increased cloud cover could potentially offset the warming induced by anthropogenic greenhouse gases.

That being said, I’m also not prepared to call AGW “a crock” either. CO2 and other greenhouse gases do absorb IR – that’s not controversial. I think we simply don’t know what the effect will be, and we’re essentially conducting a vast experiment with our atmosphere. Thus, I think it’s prudent to limit emissions to the greatest degree practicable.

thank you for your input. do current models that the AGW believers site include precipitation and solar activity too?

i cannot for the life of me understand how anybody can predict climate or temperature of a system as complex as Planet Earth 1 year from now much less next century.

my other disbelief is that something as complex as climate and weather on planet earth be dependent upon one single factor such as co2.

[JSH]

Originally Posted by wxman

No - but I do work for a federal agency (standard disclaimer - the opinions expressed here are mine and do not necessarily reflect those of the U.S. Government ).

My guess is that that he works at ORNL (Oak Ridge National Laboratory) just north of Knoxville, TN.


I like clean coal and in particular coal gasification because it increases efficiency and reduces pollutants that we know are harmful; SOx, NOx, CO, mercury, particulates. For example NOx levels of 15 ppm down from 250 - 600 ppm now. (Current emissions depend on how old the plant is)

We know without a doubt these pollutants are harmful so we should be pushing forward efforts to eliminate them.

I also don't see a short-term way forward for the electrification of personal transportation without coal powered base loads. We know that there are large efficiency and pollution benefits to switching from gasoline powered cars to EV's even if they are powered buy our current coal-fired plants.

[wxman]

Originally Posted by dbermanmd

...do current models that the AGW believers site include precipitation and solar activity too?...

The GCMs do include precip. Solar activity is included in the models' "physic packages".

With respect to precip, climate/weather models incorporate "parameterization schemes" (Precipitation & Cloud Parameterization - PCP) which are techniques for estimating precip based on certain modeled atmospheric conditions (e.g., lift, instability, CAPE). So precip is actually a "byproduct" of atmospheric processes based on the behavior of previously-encountered conditions. Precip has to be parameterized because many precip processes are sub grid scale (e.g., typical summer air mass thuderstorms - the convective cells are much smaller than the horizontal resolution of the models). Clearly parameterization does not work well with convective processes.

This is another of many reasons why I don't believe atmospheric conditions can realistically be modeled decades in the future even on the global scale. Atmospheric models represent POSSIBLE future conditions but it's really still just speculation in my opinion.