Is There Experimental Proof of CO2 Warming?

[ThankyouMoneypenny]

Originally Posted by spot1234

I now know more about contrails then I ever wanted to know. You are partly right they are formed in the way that you say. However after they are formed they act as clouds ,clouds that effect the climate, clouds that wouldn't be there if it weren't for man, hence an anthropogenic component. You want the exhaust chemicals included Nitrogen, water vapour, CO2, CO and such If you look at the bargraph it includes Ozone, Nitrous oxide, stratospheric water vapour and of course CO2. I'm a bit confused as to what you think a non contrail-producing aircraft does to the climate.

Your saying that natural forcings should be accounted for. The only one observed to vary is included in the graph linked by Windguy. The graph was linked without the notes. If you assume that the reader has some prior knowledge and knows that solar variation is not related to man. The fact that the right hand column graph clearly states 'Net Anthropogenic Component' disqualifys solar variation. I would think linking that graph to this debate is fair and the graph is not as you claim unscientific. It is at least scientific information backing up an assertion.

You claim that natural forcings are not taken into account. Again what are these natural forcings? Why won't you tell us? your implying that you know what they are and I should know what they are but you won't tell us what exactly they are, let alone the effect that they are having. If your trying to convince someone with prior knowledge its hardly a good idea to accuse your opponents of being unscientific and trying to mislead ordinary Joes then invoking mystical unspecified natural forcings that you can't even name.

LOL, yes, ok, I went into too much detail on contrails! But I think that contrails (man-made clouds if you want) themselves are probably a negative forcing. It is the chemicals within them that are positive forcings and should be included in the first GHG bar. Contrails are only the visible manifestation of the jet/turbine exhaust chemicals. Non contrail-forming aircraft are still pushing out the same exhaust gasses, you just cant see them.

There was just no need to put a solar variation/forcing/component bar in that graph. It seems to be there to act as a comparison to the anthropogenic stuff. I agree the information itself is scientific, just not the way it is displayed.

What other natural forcings are there? Ok, as a layman, I would include volcano output, water vapour from natural sources, and maybe difference in black-body radiation due to naturally changing albedo effect. I am prepared to accept that these are factors that have a good reason for not being included but I am genuinely confused as to why they are not.

As I understand it, anthropogenic CO2 is less than 5% of the planet's total CO2 production. So the rest is natural. Doesn't that count for anything when it comes to climate change?

[BestTimesNow]

This 2004 NASA article gives more blame to contrails.

Clouds Caused By Aircraft Exhaust May Warm The U.S. Climate

"NASA scientists have found that cirrus clouds, formed by contrails from aircraft engine exhaust, are capable of increasing average surface temperatures enough to account for a warming trend in the United States that occurred between 1975 and 1994."

[BestTimesNow]

Originally Posted by BestTimesNow

This 2004 NASA article gives more blame to contrails.

Clouds Caused By Aircraft Exhaust May Warm The U.S. Climate

"NASA scientists have found that cirrus clouds, formed by contrails from aircraft engine exhaust, are capable of increasing average surface temperatures enough to account for a warming trend in the United States that occurred between 1975 and 1994."

Here's the link:

NASA - Clouds Caused By Aircraft Exhaust May Warm The U.S. Climate


When you look a this satellite photo you can see the contrails in the southeastern USA.

EO Newsroom: New Images - Aircraft Contrails

click on the photo for a full screen image

[ThankyouMoneypenny]

Originally Posted by BestTimesNow

Here's the link:

NASA - Clouds Caused By Aircraft Exhaust May Warm The U.S. Climate


When you look a this satellite photo you can see the contrails in the southeastern USA.

EO Newsroom: New Images - Aircraft Contrails

click on the photo for a full screen image

Hi BestTimesNow.

Thanks for your input. I read the link and a few others and the result of my research is...

I now believe I was wrong about the negative forcing component of contrails. I have never been afraid to admit to being wrong (see my quotes at the bottom of this post) once I have enough info. So, for you and spot1234, thank you for making me increase my knowledge about forcing components! It appears that stratospheric (or at least high level) clouds/contrails have a slightly smaller albedo and slightly larger greenhouse forcing factor than low level clouds/contrails. Well done and thank you.

However, the nasa link was guilty of representing the problem in a biased fashion, which is one of the main problems I have with much of the scientific information flashed onto the global media.

For example, the title is "Clouds Caused By Aircraft Exhaust May Warm The U.S. Climate".

In the second paragraph:
"This result shows the increased cirrus coverage, attributable to air traffic, could account for nearly all of the warming observed over the United States for nearly 20 years..." is followed very closely by "During the same period, warming occurred in many other areas where cirrus coverage decreased or remained steady,"

The obvious conclusion is that there are other factors which may be outweighing the contrail component. What those factors are is probably a very large debate. In other, similar links such as another nasa link:
EO Library: Clouds & Radiation Fact Sheet
a very comprehensive picture of the forcing properties of clouds is given, and the result is that high clouds have a positive forcing but low clouds have a negative forcing.

It is my opinion that the headline-grabbing 'clouds caused by aircraft...' is designed to channel the public into leaning toward the AGW alarmist camp, whereas the other factors are left to one side because they don't grab headlines. I don't see many headlines saying things are a cooling factor. The facts are that other factors are obviously playing an important part, otherwise the temperature would be rising much faster than it is. Maybe the lower clouds caused by power station emission are enough to counteract the higher clouds by aircraft?

Thanks for increasing my knowledge.

TYM

[Windguy]

Spot1234, your graph is an old one, mine ain't that much better, but they still show most of the details.

The differences are

Carbon soot is = to 0.9W/m^2 forcing. Which means diesels will have to run cleaner.

Aerosols are now only -0.16W/m^2 (2007) IPCC report.

Contrails do have an effect of 2.4 times per litre of fuel compared to a vehicle on the ground. It's because the Stratospheric H2O released by planes don't come down within a 10 day cycle like troposphere's H2O. It still comes down, but could take years. But it still only 5% of all net anthropogenic forcings, where as deforestation is more than a third and another third is power generation.

[Windguy]

RealClimate
Clouding is one factor they haven't fully evaluated as yet, but with water vapour and clouding they are really only 66 to 85% You'll have to read the article to explain.

But water is a feedback only because we can not artificially increase or decrease water in the air. By warming the ocean though, we are removing a forcing that creates clouding and rain and can lead to a further rise in temperatures. By deforestation we are removing a fast source of evaporation (by transpiration) that helps cool the lower land levels and creates rainfall (especially monsoonal rain).

[BestTimesNow]

Originally Posted by Windguy

RealClimate

But water is a feedback only because we can not artificially increase or decrease water in the air.

This is where the climate models are wrong, by ignoring forced evaporation.

We are using 137 billion gallons per day in the US for irrigation. Some of this water stays in the crops that are sold, but most of this water will be evaporated into the air. Many states irrigate at a rate of 5 acre feet, per acre.

It’s like annually evaporating a massive lake 5 feet deep.

Here’s a chart of the irrigation water used in the US in 2000.

Irrigation water use, from USGS Water Science.

[BestTimesNow]

To get back on topic “Is There Experimental Proof of CO2 Warming?”

Let’s look at a hypothetical problem based on this part of my post in the water vapor thread:

Let’s compare two cities that have the same elevation and latitude. I’ll pick Atlanta and Phoenix for this illustration. For any given day of the year they each have the same amount of daylight hours to absorb solar energy and the same amount of nighttime hours, and we can see the effect of radiating energy back into space.

In July, the average daily, high to low, temperature swing is 18.7 degrees for Atlanta and the temperature swing for Phoenix is 29 degrees. The reason Atlanta’s temperature does not swing very much is because it has way more greenhouse gasses blanketing area. The greenhouse gasses block the sun coming in during the daytime, and trap the heat from escaping during the nighttime.

The Phoenix area heats up much faster in the day time and is able to drop more degrees at night, because it has much less of a greenhouse gas blanket, than Atlanta. (Remember, both these cities are at the same elevation and latitude.)

Does Atlanta have that much more CO2 in the air than Phoenix? Or does Atlanta have way more water vapor in the air than Phoenix? Which greenhouse gas is it?

-------------

Now, let’s pretend that a glass wall, 100 miles high was placed on the state line around Arizona and another one around Georgia. Now we have two giant fish bowls to do our experiment.

In the first experiment we will irrigate the land in Arizona. If we irrigate it every day don’t you think the climate in Phoenix will become humid and eventually be similar to the temperature highs and lows in Atlanta?

Now let’s start over for the second experiment. This time we will add CO2 to the Arizona fish bowl. If we doubled the the trace gas, CO2 in Arizona, do you really think it would have any effect on the temperature in Phoenix? Think about it!

[sandy winder]

Originally Posted by flogger

The simple truth is that NONE of the observed real world facts match the panic stricken 'green world' theories and models.

Temperatures havent risen in a decade.

Sea levels are rising by millimetres not feet and have been barely discernable over the last 30 years.

The Southern polar cap has been increasing in thickness and extent for many years.

The warmest decade recorded in the modern era was the 30s Not the last decade with 1934 the hottest of all.

2007/08 has seen some of the coldest weather ever recorded in modern times worldwide.

For example This one will make you chuckle.

Cold Irony: Arctic Sea Ice Traps Climate Tour Icebreaker « Watts Up With That?

I won't go into all these 'facts' but ...

/// The warmest decade recorded in the modern era was the 30s Not the last decade with 1934 the hottest of all.///

... is quite wrong and easily verifiable.

It was only the warmest in the USA, which is about 2 to 3% of the earths surface.

Only an American could see that as pertaining to the whole world.

But last year was the second warmest on record for the whole of the Northern Hemisphere, beaten only by 2005. So the idea that global warming ended in 1998 or 2005 is equally unlikely.

[ThankyouMoneypenny]

Originally Posted by BestTimesNow

To get back on topic “Is There Experimental Proof of CO2 Warming?”

Let’s look at a hypothetical problem based on this part of my post in the water vapor thread:...

...Think about it!

Good post again BTN. And, although the title of the thread is "Is there experimental proof of CO2 warming?", the question posed by Davaris was "I was just wondering if there is any hard experimental evidence that proves CO2 warms the environment?" In my first post on this thread I wrote: "Either way, this is one of the problems that the IPCC has in forecasting Global Warming. It uses computer models to predict an outcome but cannot input into the model all the variables that exist in our 'open' atmosphere system." This comment seems to have been ignored.

The reason that water vapour (at least) is not included in these models would appear to be that it is considered a feedback, not a forcing. This is obviously an error because the models cannot get it right. If the feedback/forcing effect of water vapour was included in the bar graph posted by Windguy (page 1), the column would dwarf the CO2 effect. This would not sit well with the AGW brigade and would not command the headline/funding-grabbing visibility they need. Until all factors can be put accurately into a model of an incredibly complex system, the models will fail.

Here are a couple of quotes worth reading:

"When water vapor feedback is present, the increase in water vapor associated with a warmer climate enhances downward longwave radiation. To maintain surface heat balance, evaporation increases, leading to a similar increase in precipitation. This effect is absent in the experiment without water vapor feedback. The large impact of water vapor feedback on hydrologic cycle intensification does not weaken as spatial scales decrease, unlike the internal variability case. Accurate representations of water vapor feedback are therefore necessary to simulate global-scale hydrologic variability and intensification of the hydrologic cycle in global warming."
Effect of water vapor feedback on internal and anthropogenic variations of the global hydrologic cycle

"Based upon the evidence, it seems likely that the neglect of sources of internal radiative forcing has resulted in diagnosed feedbacks which give the illusion of a climate system that is more sensitive than it really is. This has then led to the development of climate models which produce too much global warming in response to the external radiative forcing caused by anthropogenic greenhouse gas emissions."
Climate Science: Roger Pielke Sr. Research Group News » Internal Radiative Forcing And The Illusion Of A Sensitive Climate System By Roy Spencer

ps, how much would it cost to build a 100 mile high wall around Kyoto?