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*Please*, only answer this question if you *don't* know the answer?

What percentage of the atmosphere is CO2?

I would like to get a feel for what the average person (who doesn't already know the true figures) thinks the percentage of carbon dioxide in the atmosphere is.

We are being bombarded with hype from the global warming scare mongerers about rising CO2 levels, so what do you think the figures are.

Please, please, please, if you know the answer, or have looked it up, don't post the true figure here.

Thanks.

Update:

TOMATO - I agree that we are polluting the planet. What I have a problem with is the idea that *we* are causing global warming.

LURKINGGHERKIN - (good name, BTW) I had a look at your Sceptic Bingo website (LOL) and clicked on the link that is supposed to debunk "Ice cores show that warming precedes increases in C02." The page it linked to admitted that the first 800 years of any global warming period had nothing to do with CO2 levels, that it was the warming that produced the extra CO2, but that once the CO2 started increasing then *it* was responsible for the warming from then on. Really? LOL It also failed to mention that ice core data shows that CO2 levels continue to rise for 150 years *after* the peak in temperature. So, sorry, I'm still not convinced that human activity is having a significant affect on global warming.

Update 2:

OK, the answers seem to have dried up now, so I'll give the answer.

Before I do, let me point out a couple of things...

Firstly, let me assure everyone that the object of the exercise was not to make people look stupid. I asked for answers from people who didn't know, so *of course* everybody got it wrong.

Secondly, I find it very interesting that *everybody* guessed too high. The closest answer - 0.4% - was still about 10 times more than the actual figure.

So, what's the answer?

It is....

0.0381%

Now, for my next question, I want people to guess how much CO2 levels have increased in the lat 100 years - look out for the question soon.

How on Earth do I pick a best answer for this one? I've chosen ChaiotMember's answer because he really kept to the spirit of the question despite having a good idea of the answer.

58 Answers

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  • Anonymous
    1 decade ago
    Favorite Answer

    Well I do know that most of the atmosphere is made up of Nitrogen and the %. The next main constituent is Oxygen. I also know the %, which leaves not a lot for all the trace gases, so on that basis CO2 makes up a very small part of that remaining %. Never thought about it that way before, so well done. Very interesting! Keeping faith with your question, and wishes, I deliberately did not put in the actual percentages and I didn't know the % of CO2 in the atmosphere, still don't, although I now have a much better idea.

  • Anonymous
    1 decade ago

    i knew the anwser once, but can't quite figure out what it was. anyway, people shouldn;t be so worried about the percetnage of co2 in the atmosphere, sure it helps the global warming, but not nearly as much as H2 does, and humans have hardley put any at all of that gas in the atmosphere!! so we shouldn't be s worried about it, what we do with co2 is not as bad as they make it sound. and it's about time people stopped spreading fairytales and started learning the truth, it's not so difficult, it takes like 5 minutes to find and maybe another 5 to understand if you havn't had biology or if you're quite thick. so let's put some effort in learning the truth and stop scaring each other!!!

  • 1 decade ago

    -.-% (--- ppm) and increasing at about -.-ppm per year, with seasonal fluctuations.

    Throughout my teaching career the figure quoted was always -.-% so, although it sounds like a small amount, there has been a --% increase over the last 30 years. Prior to that the figure had been pretty stable for 100 years or more.

    Actual data available on request or from the website below. I, too, would be interested to read laymen's estimates.

  • 1 decade ago

    OK, well as you asked..I've really no idea.

    I don't understand why some people think global-warming is all scare-mongering though. Don't you think there are many large corporations and governments who have a strong vested interest in wanting you to believe its all scare-mongering? Then they can keep exploiting our planet. My cousin is a geologist and I have heard the whole its-all-scaremongering arguments. I don't buy it though.

    I don't need to know the % of C0 2 in the atmosphere, I just open my eyes and use my common sense to see that we are stuffing up our planet.

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  • Anonymous
    1 decade ago

    I'm guessing you don't want people who know the true figure to post here because you don't want anyone with a clue to rain on your little global warming denialist parade you've got going on here.

    Let me guess - you reveal the true figure to be a small fraction of 1% and then 'ta-da'! You've debunked the global warming 'myth'.

    Small numbers only equate to insignifigance in the minds of simpletons. People with actual knowledge of climate science know better.

    Now let's all play Global Warming Skeptic Bingo!

    http://timlambert.org/2005/04/gwsbingo/

  • 1 decade ago

    Yeah - broadly speaking I know the answer too - and am watching the answers coming up with interest. Good question.

    p.s. cows produce methane not Co2

    But percentage or no; the actualy amount of increase is scarily significant. Just look at the current changes and incidents to out weather patterns.

  • 1 decade ago

    3%

    But it is a pointless exersise, because we don't know what percentage will spell disaster. Like it may only be 3% of the atmostpher, but if disaster occurs at 3.2% then that is a big deal. If disaster only occurs when CO2 is 20% then 3% is nothing.

  • Anonymous
    1 decade ago

    I haven't looked at all, and i probably will be way out... but no doubt some smart-alic nob will post the real thing pretending he didn't know...

    my guess woud have to be quite low as it is poisonous to us... so i'd have to guess at something like 0.5%.. however i'd also say that as you went higher into the air into the different atmospheres i think there'd be more, as there is less O2 up there...

  • 1 decade ago

    As far as I can remember N2 + O2 = 99%, so the percentage of CO2 is less than 1 %, I guess.

  • Anonymous
    1 decade ago

    I remember from school that nitrogen is about 76%, O2 is about 20% and all the other gases make up whats left, but I dont know what percent is CO2.

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