can someone please explain how 300 ppm to 390 ppm is a 0.01% increase?

Easily.

300 ppmv is 0.03% of the total volume of the atmosphere. 390 is 0.039%, or 0.04 with rounding to be generous. That's a change of 0.01% of the total volume of the atmosp- UH, I mean, change in total CO2 concentration.

Of course, they wouldn't call it mathurbation if it was actually a useful calculation, now would they?

Casey - 0.3 = 3%? Times 100, not 10.

Mike: Oh please. The 0.01% figure is the absolute difference between the previous and current CO2 concentrations as compared to the total volume of the atmosphere. It's not in any sense a percent change, nor one (I say again) that has any useful purpose other than to misinform anyone who reads it that (a) didn't finish fifth grade math, or (b) is too lazy to remember fifth grade math.

It's actually quite deceitful to carry the usage of percentages through the entire operation as that, as the only way the percentage is tied to that number is to show it's a portion of atmospheric volume - in other words, not to show an actual percentage change. If you kept it as a fraction, 0.0003 and 0.00039, then the change is 0.0001. But 0.0001 what? That absolute change is useless, meaningless, and simply multiplying by 100% is not justified since there's no change relative to an initial amount being calculated. What MUST be done, and what WASN'T done in that previous answer (and all others he posted) is division by the initial value of 0.0003, and THEN a multiplication of 100%. That's 33.3%. The other method is invalid and useless.

%∆ = [ (f - i) / i ] * 100%

%∆ ≠ (f - i) * 100%

There is no argument behind "different usage of the same numbers," no "tricks with statistics." There's math. And then there's mathurbation.

You have good answers, with legal limits, and health based limits. Consider that the air that passes through the device has a 0.001 ppm *increase* with each pass. So if it were operated in a breadbox, it would eventually reach dangerous levels. Any normally sized room, with contents, and some functioning electrical appliances, will have some ozone background. to which this device adds. I believe it will be not enough more to cause you issues. Just watch for signs of asthma, or enhanced effects.

JFTR - I'm THE person. Ottawa & Nick have calculated correctly.

And a party at Dawie's sounds good. ;-)

There is no math trickery here.

You can describe atmospheric CO2 by either

* The Increase of Percentage OR

* The Percentage of Increase.

If CO2 has gone from 290ppm to 390ppm.

Then the Increase in Percentage of CO2 has been from 0.029% to 0.039% for a total of 0.01 %.

The Percentage of this Increase would be:

(390 - 290)/290 which comes to 34%

Warmists love 34% & freak out over 0.01%

Now I would NEVER call Warmists liars for saying 34%.

So why do they call 0.01% - misinformation, mathurbation, useless, deceitful, misleading, flat out wrong, a trick, ambiguous, twisted denier math, etc. etc. etc.?

Well it's because 0.01% sounds small & 34% sounds big.

But isn't this is the TRUTH of CO2? That there has been a big increase in a VERY small fraction of the atmosphere.

I am NOT saying 0.01% doesn't make a difference. I am asking you to look at the hysterical reaction I get by simply presenting this statistic. I want you to see WHO is afraid to tell the whole truth.

The Warmists will say one statistic is significant, while the other meaningless. I submit they both significant.

Let's use Dawei's metaphor. If 1 pint of Vodka is 290 ppm, then the party punchbowl holds 431 gallons.

Now if someone pours another pint of Vodka into the punch...

Which statistic has more meaning?:

A) That the amount of Vodka has doubled

OR

B) That the punch is went from 0.026 to 0.046 proof.

Double the Vodka sounds great until you realize it's only 2 pints in 431 gallons. I grant this metaphor isn't entirely fair, but it certainly illustrates the absurdity of saying the Percentage of Increase (A) matters while the Increase of Percentage (B) does not.

Mark Twain once said there are lies, damn lies & statistics.

I submit that Warmists are the ones more inclined to play statistical games.

Edit

Well Adrian what we have is a 34% change in 0.029% of the atmosphere & THAT is a change of 0.01% or 100ppm.

Now are you ready for the big joke?

If I had said '100 ppm' instead of 0.01% would anyone here not recognize that number? We all know CO2 has increased 100ppm, right?

Take a good look at all these people accusing me of deceitful, misleading, ambiguous, twisted denier math.

I am charged with lying & failing to identify the value as total atmospheric percentage.

But per-centage just means part per hundred.

Hence 100ppm is the SAME as 0.01pph is the SAME as 0.01%. All this anger & emotion over a simple change in nomenclature.

And why? Because 0.01% accurately expresses just how small the amount of atmospheric C02 is.

I'm not saying that can't drive Global Warming, I'm just saying it's bloody unlikely. That number should make you gasp and hang on to at least a scrap of skepticism.

As a Conservative I found the economics of CO2 very suspicious. Control CO2 & you control the power that runs the world.

When the hockey stick turned into 15 years of no warming, my skepticism increased. Then came this absurd crusade of 'settled' science & labeling Skeptics as Deniers.

When your big prediction fails, it's time to admit you don't know, not swear that you are sure.

I don't care that Warmist believe, I DO care that they profess to KNOW when there is much cause to doubt. Advocate all you want, just lose the attitude. Climatology is suppose to be Science not Religion.

Another answer says "You can have two people use the same numbers and present different stories without actually lying about the original numbers." That is one of the problems with the "skeptic" attitude--clearly the intent of the person that's claiming a 0.01% change is to mislead people--that's the only reason to phrase it that way. Unfortunately other "skeptics" condone this practice by never correcting their buddy.

The way around this problem is to only speak of the mass or amount of CO2, then when they give false numbers they can't make the claim that they are not technically lying.

EDIT: Self-professed "skeptics" tell us all the time how we don't take them seriously as skeptics, but then when someone like PQ intentionally tries to mislead people (and it's very clear that's what he's trying to do), do they speak up and call him on it? Nope, they either defend him (OM, Orwell, Mushman) or sit on the sideline with their mouths shut (the geologist, chemist, statistician). It's the same thing with the lies other "skeptics" spread about volcanoes producing more CO2 than human, I'm sure they all know it's a lie, but we see that in here again and again.

This is the reason that people call you "deniers" rather than "skeptics," folks--you need to demonstrate that you care about the truth and not just advocating your political position. The amount of CO2 in the atmosphere has increased about 40%--the more you let your ideological cohorts get away with sophistry the less you look like skeptics and the more you look like liars.

EDIT for Mushman: If you don't realize that I will correct people that believe in AGW then you haven't been paying attention. Here's an example where I point out that recent warm temperatures are an example of weather, not climate:

http://answers.yahoo.com/question/index;_ylt=AlbXD...

I also point out that the asker incorrectly refers to the chart being of thickness when it was actually height. In the current tornado question I also mention that I agree with some of what Peter J said (although he got stuff wrong too). As for the one quote from Hansen from the last century, Yahoo Answers was not even around then, so I don't know how I was supposed to object to it.

Sorry, I have no interest in letting someone slide on a factual error or misrepresentation because I agree with some of their politics, I hold science in greater esteem than that. If someone wants to be a skeptic and not a "skeptic" then they should do the same thing.

As several answers have already indicated, this is a problem of (a) semantics and (b) deliberate deception.

Your difficulty is that you've been trying to argue with liars by using their terminology. To do that you need to at least understand the terminology. You learned real math in school, but probably didn't learn liar-denier math. It goes something like this:

STEP 1: Cheat sheet

a) 2+2 = we don't know

b) 2+2 = we can't know

c) 2+2 = who cares

d) 2+2 = a liberal environmentalist marxist originalist rationalist hoax

e) 2+2 = a matter of opinion that we need to openly "debate" here in this "forum"

f) 2+2 = a natural phenomenon we can't do anything about no matter what

g) 2+2 = 6 (counting the + sign as two ones)

h) 2+2 = 8 (counting the + sign and the equals sign as two ones)

i) 2+2 = it depends what kind of story we want to tell

j) 2=2 = not whatever you think, because your dog ate my homework to hide your decline

k) 2+2 not= 4, because classmate Johnny says it does, but he once incorrectly stated the fifth number after the decimal point when reciting the digital approximation of pi.

l) 2+2 = such a small number, it doesn't matter

STEP 2: Pick an answer from A through L above that you haven't made a fool of yourself with lately

STEP 3: Disguise it slightly to make your copy-paste look slightly less ridiculous

STEP 4: Call anyone who says 2+2=4 a bad name, in order to "prove" them wrong

STEP 5: Repeat steps 1-4 endlessly, until the teacher or other students give up or you are expelled

A question that goes to the heart of denial maths or as Ottawa puts it tricks with statistics, denier continually try to play down Co2 by talking about the volume rather than the effect, what they invariably forget to mention is that the total volume of all greenhouse gases is just 1% of the total volume of the atmosphere and that 1% lifts global average temperature over 30c.

But then looking at that blows their argument out of the water so they tend to try and ignore it.

As most 'alarmist's' use the direct measurement of Co2 rise i.e. 300 to 392ppm that is by any meaningful math around 40% there is also to a lesser extent the rise in methane which is around 20 times the effect of Co2 but there is far less of it in the atmosphere.

http://www.newscientist.com/article/dn11652-climat...

Many denier arguments are based on this sort of deliberate misleading information.

Edit 280ppm is the pre industrial level, the level around 1960 was ~315ppm so it has risen about 35ppm over ~100 years from around 1850-1960 and in the last 60 years it has risen a further 77ppm at the current time it is now rising at ~ 2ppm per year. One of many denier pet theories is that Co2 is logarithmic in effect i.e. a small amount creates an effect then a much larger amount is required to create further effect, I'm not sure if they really understand the logarithmic effect if they can't see that sort of rise in the above numbers a hundred year increase of 35ppm followed in almost half the time by a more than doubling would seem pretty logarithmic to me and at the current rate of 2ppm that's a further rise of at least another ~180ppm by the end of the century, most likely more as the yearly rate is only increasing

http://www.esrl.noaa.gov/gmd/ccgg/trends/

Peter: "Percentage increase 300 to 390 in simple math = 23.07693 %"

You sure you want to say that, some very simple math for you what is 10% of 300

Hope you said 30, (3 x 30 = 90) (3 x 10% = 30%) are you still with me, am I going to fast!

So 30% of 300 = 90 so that would be a rise (since 1960) of 30% and from the original pre-industrial Co2 level of 280ppm is 40% to the current figure of 392ppm, please buy yourself a calculator.

Yes, I can explain this, and I'll do it rather simply and an unbiased way, because either the .01 percent statistic was explained to you out of context, or you misinterpreted the statistic when it was posited in the correct context. You must pay attention to the semantics.

It's a 30 percent increase in CO2 VOLUME which translates to a .01 percent increase in CONCENTRATION when you account for the total atmospheric composition.

If you take the number 300 and increase it to 390, then it's pretty straight forward. When compared to the number 300, a number of 390 is a positive increase of 30 percent.

BUT this is just a number. Remember, PPM is parts per million. It's including the entire atmospheric composition. So,

300 parts per million translates to 0.00030 in decimal, and therefore,

IN THE EARLY 20TH CENTURY, THE MEAN GLOBAL ATMOSPHERE HAD A CO2 CONCENTRATION OF .030 PERCENT

Fast forward to today, 390 parts per million translates to 0.00039 in decimal, and therefore,

PRESENTLY THE MEAN GLOBAL ATMOSPHERE HAS A CO2 CONCENTRATION OF .039 PERCENT.

Do the math, it's a difference of .009 percent, close enough to round up and call it a .010 percent increase in THE MEAN GLOBAL ATMOSPHERIC CO2 CONCENTRATION.

Deciding whether or not 300ppm to 390ppm are true statistics will be left up to you, the readers. But please, if you post about statistics, explain it in the right context and semantics so others can understand it fully.

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EDIT

Pheonix, ah so you're the one all this hoopla is about. You actually stated your facts very clearly so it was a misinterpretation of your statements after all. Glad to meet a fellow skepti--- ah, I mean "denier". Shall we call the dyed-in-the-wool believers "Gore goose-steppers" to make it an even playing field of irrational name calling?

All kidding aside, I'm sure plenty of those reading these posts are shaking their heads thinking, "what a bunch of closed-minded deniers", as if this issue is settled with no room for consideration based on simply how much carbon compound is in the air. We're skeptical of this notion of emission-based global warming, we are NOT discounting it completely. We just rightfully find it unlikely in the face of all other factors that could change climate. Ironically, goose-steppers are the close-minded deniers by not considering any other factors.

I wonder if those who have made up their minds that warming is anthropogenic truly grasp what the concept of a low part-per-million is. An increase in 100 ppm is 1/10000th of the total atmosphere. Can you truly visualize what 1/10000 is? it's a cap-full of extra carbon in a swimingpool. A drop in a bucket. Whatever analogy you want to choose. This tiny additional amount is positively DWARFED by the amounts of water vapor in the atmosphere. Yes, water vapor is pound-for-pound, a more efficient greenhouse gas and it's always there, kept at a stable global average by it's thermal properties (when it reaches a saturation point based on ambient temperature it condensates and precipitates). Just something to think about.

Is the "certain person" suggesting that the tiny amount of CO2 in the atmosphere could not possibly capture enough heat to raise global temperatures? Good question. Here's the answer from the climate change class that I took: A photon of infrared energy traveling from the surface of the earth must travel through several miles of air. Over several miles, it is quite likely that the photon will encounter at least one C02 molecule. That molecule will absorb the heat energy, the re-radiate it in a random direction, usually retaining the heat in the atmosphere.

The other evidence that CO2 is trapping those IR photons is that spectral measurements taken from satellites can see the absorption band of CO2.

The extra CO2 initiates a positive feedback as warmer air causes more evaporation of ocean water, adding more water vapor to the air. Water vapor is a strong greenhouse gas.

That math is correct as you state. However, it is a moot point since CO2 conc is driven by temperature. As seawater warms up it can't hold as much CO2 and must therefore release it into the atmosphere. The driving question to be answered then becomes what is causing the seawater to warm up?

The person you refer to, like Ottowa Mike, should not discuss statistics. They do not understand the meaning of words.

The increase from 300 to 390 is NOT an increase 0.01%. It is NOT accurate to say it is and anyone who says it is is flat out wrong. People who know what they are talking about do not make tricks with words; they use clear and accurate terminology.

It might be accurate to say the increase is .01 percentage point; that is a different thing than at 0.01% increase -- but even then you should specify what the percentage point is: "The increase as a portion of the atmosphere is .01 percentage point". It helps to be clear, but there are those who lurk here who purposely try to blur facts rather than speak clearly.

Regardless, anyone who points to the percentage point increase of CO2 in the atmosphere as an indication that humans cannot affect the atmosphere has no clue how the atmosphere works and should not be answering anyhow. Were the portion of greenhouse gasses in the atmosphere too small to create the greenhouse effect, then the earth would be too cold for life. Obviously 300 ppm is sufficient to create enough warmth for life despite the small portion of the atmosphere, and a 40% increase in that portion is clearly enough to enhance the greenhouse effect and generate increased heat retention.

*********

Oh, I like Dawei's answer. Actually I want to change it. If he were throwing a party with thousands of gallons of grape soda, and there was on bottle of vodka there, a denier could bring a second bottle to the party and, with lamp shade on head, insist that he could not be drunk on two bottles of vodka because it was a very small amount of the beverages that Dawei was serving.

"Eeets ony teeny weeny bit. I kant be dunk, lookt all the soda. I kint get drunk 'hkp with so much soda here."