Someone emailed me this article which quotes Plimer:

Plimer adds he doesn't want to rain on our parade too much (not half!), but he should mention that when Mt Pinatubo erupted in The Philippines in 1991, it threw out more greenhouse gases into the atmosphere than the entire human race had emitted in its entire time on earth. It was active for more than a year.

This statement is so demonstrably wrong (and yet going viral), it deserves a direct response just to show what a discredited source Plimer is. Does anyone know the original source where Plimer first said this?

Don't know the source of that exact quote, but here's a similar one:

"Over the past 250 years, humans have added just one part of CO2 in 10,000 to the atmosphere. One volcanic cough can do this in a day."

Nope, but how easy is that line to debunk? Pinatubo emissions greater than all of human history? Crikey! Math is clearly not a "skeptic" forte.

Do you want a specific rebuttal to this? If so, I'll try to track down the original reference.

Here it is (emphasis added)

"The volcanic ash emitted into the Earth’s atmosphere in just four days – yes – FOUR DAYS ONLY by that volcano in Iceland, has totally erased every single effort you have made to reduce the evil beast, carbon.  And there are around 200 active volcanoes on the planet spewing out this crud at any one time – EVERY DAY.

I don’t really want to rain on your parade too much, but I should mention that when the volcano Mt Pinatubo erupted in the Philippines in 1991, it spewed out more greenhouse gases into the atmosphere than the entire human race had emitted in its entire YEARS on earth. Yes folks, Mt Pinatubo was active for over one year, think about it."

I'm not convinced Plimer actually wrote that, although the blogger suggests that he did.

Dana, your link appears broken.

Both worked for me, Rob

Righto, got it to work. Some web browser glitch I imagine.

All of human emissions compared to Mt Pinatubo would look very funny. 

"All of human emissions compared to Mt Pinatubo would look very funny. "

Sounds like an idea for a graphic for jg to work on...

It's a little derivative of jg's earlier graphic which is why I was loathe to bring it up but upon reflection, there's nothing wrong with repetitiveness. On the contrary, repetition is a strong communication technique and we should embrace it rather than avoid it. So what about we find out how much CO2 Pinatubo emitted (probably hundreds of millions of tonnes) versus how much CO2 humans have emitted (over 1 thousand billion tonnes) and compare them visually. That would be a useful, strong graphic for anyone who encounters the Pinatubo CO2 argument.

From Terry Gerlach's latest paper - 2010 human CO2 emissions were 700 times greater than the CO2 from the Mt Pinatubo eruption.

Maybe a graphic and a link to Gerlach's paper is all that is required for a basic version rebuttal? The intermediate version could point out the rather obvious flaws in the argument. 

I'm still in favor of the total thingy.  If 2010 emissions (30 Gt) were 700x then Pinatubo was about 21Mt.

Found this:

Humanity has to date burnt about 300 Gt C of fossil fuels.

Not exactly CDIAC, but a number.

From Gerlach above:

Even the Mount Pinatubo paroxysm on 15 June 1991—one of the three largest eruptions of the twentieth century—with an estimated CO2 release of about 0.05 gigaton, would not have overrun the upper limit.

So Gerlach says Pinatubo was about 50 Mt.  Also per Gerlach, peak emissions of Pinatubo only matched that of mankind:

The nearly 9-hour duration of both the Mount St. Helens and Pinatubo paroxysms gives average CO2 emission rates of about 0.001 and 0.006 gigaton per hour, respectively. Intriguingly, the anthropogenic CO2 emission rate of 35 gigatons per year—equivalent to 0.004 gigaton per hour—is similar. So, for a few hours during paroxysms, individual volcanoes may emit about as much or more CO2 than human activities.

We need more solid numbers; right now we have 50 Mt of Pinatubo vs 300 Gt...found this showing peak rates of the Iceland volcano (maintain for a few days):

And this, better info from the USGS:

* Equal to 2% of the world's coal-fired electricity-generating capacity.
**Ratio of annual anthropogenic CO₂ (35 Gt) to maximum preferred estimate for annual volcanic CO₂.

Over half a trillion metric tons of carbon dioxide so far, according to these guys: The Trillionth Tonne.

So (rounding up to 549 billion) total human emissions are 10,980 times greater than the Mt Pinatubo eruption. Just like the original poster JC linked to claimed.......not!  

Using 549,957,000,000 gives us 10,999 greater. Make it 11,000 times greater than Mt Pinatubo, and be done with it. 

Found this on RC