2011-04-14 21:27:15What was it like the last time co2 levels were this high?
John Cook

john@skepticalscience...
60.231.60.165

New blog post:

What was it like the last time co2 levels were this high?

Was thinking of sending this one off to Huff Post and/or Guardian. So feedback with that in mind is welcome.

2011-04-14 22:50:38
Daniel Bailey
Daniel Bailey
yooper49855@hotmail...
97.83.150.37

Dunno where you might mention it, but perhaps some brief discussion or mention of interglacial maimums relative to today's T & CO2 levels might be in order.

 

For example:

  • The temperature maxima achieved in this interglacial is somewhat less than the last 3 (until the last 20 or so years)
  • Yet the peak CO2 levels at any point in the last 400,000 years prior to the modern era is 298.7 ppmv (with ample warming in the pipeline as a result).
  • As a result, even 350.org may have set a "too high" target themselves.

 

The Earth's climate is like a pressurized boiler, running best in an established natural range.  We are now far, far into the "Red Zone"...and the ascent is itself increasing more than linearly (the pressure is spiking)...

If the Earth's climate is the Titanic, the helmsman has it aimed squarely at the iceberg while the Captain is ordering for "Flank Speed!"...

2011-04-15 00:53:36
logicman

logicman_alf@yahoo.co...
86.145.235.170

John: this paper suggest that the climate was like a continuous el nino:

www.colorado.edu/GeolSci/faculty/molnarpdf/2007Geosphere.MolnarCane.WhichElNino.pdf

 

May I suggest that it would appeal more to general readers if these questions were addressed:

What might the modern world be like under such continuous el nino conditions?

What would the impacts be on our current populations, agricultural methods, lifestyles and global economy?

 

Minor typo:

... movements like 350.org who they tell us we need to ...

2011-04-15 05:54:11good
dana1981
Dana Nuccitelli
dana1981@yahoo...
69.230.97.203

Looks good.  I went in and made a few minor edits, including fixing the typo noted by logicman.

The end is a bit weak and could use something like "...or we may eventually face the potentially catastrophic conditions of the Pliocene once more."

2011-04-15 15:29:30John Cook. Basic level for this post?
villabolo

villabolo@yahoo...
76.167.96.50

John; is this post at Intermediate level? Is there a basic level? If not, is it OK that I write one?

I would be covering the suggestions made by logicman:

"May I suggest that it would appeal more to general readers if these questions were addressed:"

"What might the modern world be like under such continuous el nino conditions?"

"What would the impacts be on our current populations, agricultural methods, lifestyles and global economy?"

I would also suggest taking logicman's suggestions, at an intermediate level, and expand your post. Even non-general audiences at Intermediate and Advanced levels should be interested in an elaboration on those two issues.

I'm sure that the answer 'Skeptics' would give to an undecided general audience would be along the lines of "So what? A warmer Earth is good for us. Nature survived well."

Emphasis must be placed, not on nature's survival of the Pliocene (there have been worse epochs) but on the fact that civilization is much more fragile than nature. Especially when the transition into a warmer state happens very rapidly wit AGW as opposed to nature's slower, more adaptable changes.

2011-04-15 16:42:29This post is basic level
John Cook

john@skepticalscience...
60.231.60.165

Eg - I've written it as simply and briefly as possible, hoping to get it in some mainstream outlets. But it's not a rebuttal - just a blog post so having intermediate versions aren't obligatory. But if you want to write a fleshed out version, great - especially if it can be applied to a rebuttal somewhere (or grafted into an existing rebuttal).

2011-04-15 17:27:59
Ari Jokimäki

arijmaki@yahoo...
192.100.112.210

"This tells us our climate is sensitive to changes in CO2."

I think you are jumping to conclusions here. While the connection with high CO2 levels and high temperature is suggestive, you haven't addressed the situation of other forcings. I would make this statement more conditional ("might be" instead of "is" for example).

2011-04-15 18:12:10
Glenn Tamblyn

glenn@thefoodgallery.com...
124.176.171.83

John

If this is aimed at HP or the Guardian, may be make it simpler and punchier. - The paper shows how warm current CO2 levels will make the world. Don't confuse the punters with Temp rise wrt pre-industrial AND wrt current. Push the sea level rise angle harder. Push more strongly that if we stopped ALL CO2 EMISSIONS TODAY, ths would still be the future. Maybe touch on some of the other 'small problems' of such a warmer world.

Outside the world of Joe Public, this paper is support for CS being significantly more than 3 when long term effects are factored in. But this doesn't come through strongly in the piece.

Learning oppurtunity for the average punter. Where we are now is already VERY serious. But Also!!. The effects build up over decades and even centuries. The decades our grandchildren will be living through.

 

2011-04-15 19:01:32Good post
James Wight

jameswight@southernphone.com...
112.213.198.175

A couple of comments:

  • If it’s aimed at mainstream media it’ll probably need a more engaging start, but I can’t think of one.
  • “The last time CO2 levels were that high were” should read “The last time CO2 levels were that high was
  • Wasn’t three million years ago the late Pliocene, not the early Pliocene? According to Wikipedia, the Pliocene lasted from 5.3 to 2.6 Ma.
  • Maybe you might want to add that although these conditions happened in the Pliocene, that was before homo sapiens existed. So deniers can’t argue we adapted to it then. Plus today the climate is changing many times faster.

Interesting paper; sounds like it supports Hansen’s argument about slow feedbacks. Also interesting about the constant El Nino conditions in the Pliocene – I haven’t heard of that before. It reminds me, I must get around to reading Six Degrees by Mark Lynas, which has been on my reading pile since Christmas.

 

2011-04-16 18:22:33
James Wight

jameswight@southernphone.com...
121.79.12.163

@Glenn: "Push more strongly that if we stopped ALL CO2 EMISSIONS TODAY, ths would still be the future."

That’s not necessarily the case. If we stop all CO2 emissions now, the oceans should absorb some of the extra CO2 relatively quickly (though it would take 100,000 years for weathering to absorb the rest). Concentrations would start dropping, and if they drop below 350 ppm before slow feedbacks can kick in, that would get the Earth back in approximate energy balance, which should stop further warming from slow feedbacks.

The real problem is that politically it doesn’t look like we’ll reduce emissions fast enough for carbon sinks to take over anytime soon.