And, since you also seem to be using the "only a tiny fraction of the CO2 emitted each year is from fossil fuels, so it's unimportant" argument, I think it's time to bring in one of my canned answers, with my fountain analogy.
You need to understand the difference between biological carbon and fossil carbon.
The CO2 in your breath is biological carbon. It came from carbon-based fuels (like starches and fats) that you ate. Unless you're eating petroleum products or something, the carbon in those carbon-based fuels came from the biological carbon cycle. That means it came from plants that made long chain carbons (like starches and fats) from CO2 that they took out of the air. So by breathing, you're only returning CO2 that was already in the air before the plant grabbed it, and thus you're not increasing the (average) amount of CO2 in the atmosphere, you're just recycling it.
Fossil carbon, however, is carbon that hasn't been in the biological carbon cycle. When you burn coal or oil, you are adding the carbon it contains to the biological carbon cycle. Some of that excess carbon will be absorbed by plants, but some will not. So, in general, burning a fossil fuel will increase the amount of CO2 in the atmosphere.
You can think of the biological carbon cycle as a little like a fountain. The CO2 pouring into the air from things breathing (or from forest fires and the like) is like the water pouring into the bottom basin of the fountain from the top. But, all that water is water that was pumped *out* of the bottom basin of the fountain, it's just being recirculated. No matter how fast the fountain is flowing, it will never overflow just from that circulation.
Now, CO2 from burning fossil fuels is like a hose dribbling water into that same fountain. It may be a much, much, much smaller flow of water than the water from the top of the fountain, but it *can* eventually make the fountain overflow.
That sounds about right. Certainly water vapor is the most important greenhouse gas on the planet.
Still, even a 1% change in the atmosphere WILL have effects. They may be hard to predict exactly but do not let that lull you into thinking the effects can just be ignored. And above all do not use your own inability to see any effects now as an excuse to change the atmosphere more and more every year until the effects become all too obvious.
And your link totally ignores the fact that the amount of water vapor in the atmosphere is dependent on temperature.
Do we count the water vapor that is in the air because of man made carbon dioxide as natural or anthropogenic?
They do no ignore water vapor. Water vapor is an important part of it, you just don't know what you are talking about.
Water vapor is short-lived in the atmosphere and is a positive feedback that amplifies the warming from other sources such as increased CO2. If you actually read the IPCC Assessment or other scientific literature you would know this.
Yes, water vapor is the largest greenhouse gas u the gases primarily responsible for AGW are CO2, Methane, Nitrous oxides, Low level Ozone and the CFC/GCFC family of chemicals. These gases are increasing in our atmosphere every second of every day You know this, so why keep posting these innocucuous questions
Will deniers ever stop trying to mislead people regarding water vapor in the atmosphere?
Human impact id undeniable. The extent of the impact imposed by humans compared to the entire greenhouse effect is not know. Perhaps we are the straw that broke the camel's back. Perhaps our contribution is negligible. As of now, we don't know.
How can earth have all this plant life with 3% plant food?
I totally agree. our planet can never heat up too much because water vapor, though it is a greenhouse gas it also acts to transport heat from the surface to the top of the troposphere, by evaporation and convection, at the same producing clouds which reduce albedo.
It's like a heat engine, the hotter it gets the faster it works, the more heat it removes.
Our climate is dominated by all this water and ice.
That is just too scientific. The greenies claim to own science. But they never use it.
I saw pictures illustrating that exact point in my grade school science book back in the 50s.
... except Water Vapor?
http://www.geocraft.com/WVFossils/greenhouse_data.html
Water vapor constitutes Earth's most significant greenhouse gas, accounting for about 95% of Earth's greenhouse effect. Interestingly, many "facts and figures' regarding global warming completely ignore the powerful effects of water vapor in the greenhouse system, carelessly (perhaps, deliberately) overstating human impacts as much as 20-fold.
