Is there any experiment to prove that CO2 with the atmosphere concentration can have greenhouse effect?
Your question about water vapour is quite a common one among people learning about the greenhouse effect. Once you discover the relevant proportions of water vapour and CO2 in the atmosphere, it's perhaps natural to assume that the CO2 can't be playing a major role. In reality it doesn't work like this, for at least a couple of reasons. First, let's look at what the 98% actually means in practice.

It's not just about the concentration

The concentration of a gas in the atmosphere isn't the only thing that determines its warming potential -- otherwise nitrogen, at 78% concentration, would be the most important greenhouse gas. Each gas has a different radiation absorption spectrum, and a different warming potential. So despite its much greater prevalence in the atmosphere, water vapour only has about twice as much long-wave absorption potential as CO2. 

At this point, you may be thinking ‘but twice as much is still a lot more, so the CO2 can't be significant!’. But there's another non-obvious factor here, which has to do with the difference between feedbacks and forcings.

Forcings versus feedbacks

In the climate system, CO2 concentration is a forcing, whereas the water vapour concentration is a feedback. To illustrate the difference, here's a crude analogy:

Suppose that I'm trying to lose weight, but I'm reluctant to reduce the 300 grams of delicious chocolate cake that I eat every day. Having read that the human body is around 80% water by weight, I conclude that the cake can't be a problem: after all, I drink 2 kg of water per day, so it would make more sense to reduce that! So I cut down to 1 kg of water per day and maintain my cake intake. Several weeks later, I'm surprised to find that I haven't lost any weight! What's happened? It turns out that the human body regulates its water content, so reducing my intake just reduced my output. Fat storage isn't regulated in the same way, so the cake keeps piling up.

It's a similar story with CO2 and water vapour: CO2 concentration in the atmosphere actually changes for a long time (decades to centures) when we release more gas. Water vapour is, in effect, self-regulating. If we could wave a magic wand and instantaneously remove all the water vapour from the atmosphere, here's what would happen:


(source)

Within 50 days, the water vapour is back to  within 1% of where it would have been without our intervention.

So, if the water vapour concentration isn't controlled by input, what is it controlled by? Temperature. The warmer the atmosphere is, the more water vapour it can hold. This means that when the temperature goes up due to increased CO2, the water vapour content also increases, which further intensifies the greenhouse effect. It's acting as a positive feedback.

Since you're not the first person to ask this question (by a long way), there are already some good resources online specifically addressing the different roles of water vapour and CO2 in global warming.


"Common Climate Misconceptions: The Water Vapor Feedback" is a 2008 piece in the Yale Climate Connections series saying more or less what I've said above, but in more detail and without the cake analogy.
"Water vapour: feedback or forcing?" is a great 2005 essay by Gavin Schmidt explaining the role of water vapour in climate change.
"Explaining how the water vapor greenhouse effect works" is a brief Skeptical Science piece mainly focusing on the positive feedback effect.


Laboratory measurements of CO2 absorption

You seem to be particularly interested in laboratory experiments on
carbon dioxide absorption. As an excellent starting point, I can
recommend the (currently) 26 publications in AGW Observer's list of 
papers on laboratory measurements of CO2 absorption properties. If you're really keen to see experimental confirmation that CO2 can still absorb radiation even at atmospheric concentrations, you could take a look at (for example) Taylor and Yates (1957), Yates and Taylor (1960), or Streete (1968), all of which clearly demonstrate that CO2 absorption bands are present in normal atmospheric air.

As an aside: personally I find find that the numerous spectroscopic observations of the whole atmospheric column -- from satellites or ground stations -- provide a more compelling demonstration of the greenhouse effect. After all, the atmosphere isn't a homogeneous bottle of gas that can be faithfully scaled down into a lab sample. But your question and subsequent comments indicate that you're not interested in measurements of the atmospheric column itself, so here I'm just concentrating on ground-level experiments which demonstrate the long-wave absorption properties of CO2.

Answers to comments


  If there is a such positive feedback exist without other negative feed backs, the earth will get warmer without co2 contribution.


I think you might be a little confused about the definition of a feedback here. As I've tried to explain above, the term ‘feedback’ means that the water vapour content is determined by other factors within the climate system. It can amplify the effects of forcings, but it can't in itself ‘push’ the system one way or the other. So you can't have a positive feedback without some kind of forcing: the forcing is precisely the input which the feedback is ‘feeding back’ into the system, in this case via the global temperature increase.

To understand the difference, it might be helpful to think about another form of feedback familiar to a lot of people -- audio feedback through an electric guitar and amplifier system. As you can see in the linked video, there's no sound until the guitarist plays a chord. But once he does play a chord, the guitar pickup itself detects the amplified sound and feeds it back into the amplifier, creating a loop which sustains the sound indefinitely. You can think of the initial chord as analogous to the CO2 input, and the feedback loop as analogous to the water vapour effect: the audio feedback, like the water vapour feedback, doesn't do anything until it's got an initial input from some other source.


  All co2 released from fossil fuel was in the atmosphere during the dinosaurs time. If co2 release from all fossil fuel, it will restore the dinosaurs time atmosphere status. ... you can not deny that those co2 was in the atmosphere in earth history and earth animals and plants flourished


This doesn't really have much to do with your original question! If you want to ask about this, please go ahead and post a new question; StackExchange isn't a discussion site, and we try to keep each question focused on a single topic.

With this in mind, I'll just give a very brief answer here. Your formulation is a little inaccurate: the age of the dinosaurs spans at least 135 million years, there was a lot of carbon burial before it started, and all the carbon currently in the ground wasn't in the atmosphere at the same time. However, it is true that the Earth has seen higher CO2 levels than at present, and that much of that excess carbon is now locked up in fossil fuels. So what would happen if we put a lot of that carbon back in the atmosphere and tried to recreate the high-CO2 atmosphere that, say, T. rex breathed in the Late Cretaceous? Back then, the Earth was a lot warmer, with little or no ice at the poles. One of the biggest effects of re-releasing all that carbon would be the melting of our current polar ice sheets, raising sea levels by some tens of metres. The problem is not that the Earth will become completely uninhabitable by any life form whatsoever (although many current species will go extinct). The problem is that a lot of species, including Homo sapiens, are poorly prepared for a climate change of this magnitude. Ten percent of the world's human population and 8% of its urban land area is in low-elevation coastal zones, and would be completely submerged by a 10-metre sea-level rise -- which is still far less than the sea levels seen during the age of the dinosaurs.

Sea-level rise is just one effect among many, but for now I'll leave it at this since (as I mentioned above) this isn't related to your original question.


  If a person cut his water intake in half, he will get sick before he can get fatter.


This is a little peripheral to the question, I think :-). If you don't like the analogy you can ignore it: it's not essential to the explanation. However, just to reassure you: the EPA Exposure Factors Handbook (2011 edition) gives a mean value of 1,043 ml for the daily drinking water intake of an adult in the US. Thus, I don't think that restricting one's water intake to 1 kg per day, as in my thought experiment, would necessarily cause sickness.



References


Streete, J. L. (1968). Infrared measurements of atmospheric transmission at sea level. Applied optics, 7(8), 1545-1549.
Taylor, J. H., &amp; Yates, H. W. (1957). Atmospheric transmission in the infrared. JOSA, 47(3), 223-226.
Yates, H. W., &amp; Taylor, J. H. (1960). Infrared transmission of the atmosphere (No. NRL-5453). Naval Research Lab, Washington DC.