Ten Degrees, Part Deux - erratum et apologia

[GliderGuider]

Last edited Fri Nov 23, 2012, 11:49 AM - Edit history (1)

My +10C scenarios were developed based on my misreading of McKibben's statement of how much carbon there is available to be burned in fossil fuel reserves. The Rolling Stone article was unclear, and said 2,795 Gt of carbon, when in fact they meant 2,795 Gt of CO2. The true number they meant therefore is less than 1/3 the amount I was working with. So the actual warming potential if we burned it all is in the range of +5 degrees or so. It's still too high for the continuation of civilization as we know it but not quite the planetary existential calamity I was worried about.

Mea culpa for not cross-checking the numbers before I ran with them.

This also points out the risk associated with having a doomer mentality. The ability to accept extremely negative information can result in believing erroneous information just because it presses one's "confirmation bias" buttons.

I withdraw the OP. Back to the drawing board for me...

My apologies to all who were misled by me error.

[NoOneMan]

1. The cockroaches laugh at your alarmist hyperbole

Ok, read. Well, Ill stick to my original point. Who cares? 3 to 9 species will make it and Ill get to enjoy the new iPhone 7.


Sigh.

[AverageJoe90]

3. Unfortunately, the snark is actually based in truth more than you may know.

Some of the stuff that's been posted by Paul here is indeed hyperbole, like it or not. 16-18*C by 2100? Not even close to possible, under ANY circumstances.

Even the most pessimistic legit models don't have us reaching much more than 7*C by 2100, and even that, while still possible, isn't likely by any means.

When people keep exaggerating like this, it makes it harder for those people actually in the know, like the Skeptical Science guys or Peter Sinclair(yes, our very own GreenMan!), to get the message out. I seriously don't get why it's so hard for some to understand that playing the "Chicken Little" role is about as risky as blowing the problem off, because it's really not that hard to figure out.

[GliderGuider]

5. Before you snark too hard, I'd suggest you look this backcast

I've been using historical carbon emission records (1751 to 2008) from here:
http://cdiac.ornl.gov/trends/emis/tre_glob.html

I just plugged those numbers into my spreadsheet, and got this:



This is using a climate sensitivity of +3.0C per doubling. The blue line is my calculation based on the raw carbon data, the yellow line is from the [link:ftp://ftp.cmdl.noaa.gov/ccg/co2/trends/co2_annmean_mlo.txt|Mauna Loa records]. You can see how close the CO2 concentration is (it's within 1.5% from 1959 to 2010), and the temperature rise came out to 0.78C, just 2.8% low, starting from a temperature of +0.0 in 1800. I'm pretty happy with those results.

So the most I can give you is that you can use the +3C lines in my OP graphs if prefer. That's why I put them in there, after all

The reason nobody talks about rises over about 6C is not because the math won't work out, but because the social consequences are too hard (or uncomfortable) to predict. You'll notice I did say that my BAU scenario was unrealistic, right?

When you say "even that ... isn't likely by any means" what are you basing it on? Anything beyond the fact that you haven't heard many people talking about it? Because if that's it, it's your own psychology talking. Dr. Jim Kiehl from NCAR has certainly talked about a +14C world by 2100, with CO2 of 1000 ppm. That's one of the temperature results my BAU model shows.

Try reading this: https://www2.ucar.edu/atmosnews/news/3628/earth-s-hot-past-could-be-prologue-future-climate

Kiehl drew on recently published research that, by analyzing molecular structures in fossilized organic materials, showed that carbon dioxide levels likely reached 900 to 1,000 parts per million about 35 million years ago.

At that time, temperatures worldwide were substantially warmer than at present, especially in polar regions—even though the Sun’s energy output was slightly weaker. The high levels of carbon dioxide in the ancient atmosphere kept the tropics at about 9-18 degrees F (5-10 degrees C) above present-day temperatures. The polar regions were some 27-36 degrees F (15-20 degrees C) above present-day temperatures.

Kiehl applied mathematical formulas to calculate that Earth’s average annual temperature 30 to 40 million years ago was about 88 degrees F (31 degrees C)—substantially higher than the pre-industrial average temperature of about 59 degrees F (15 degrees C).

Here's the ThinkProgress piece on Kiehl's paper: http://thinkprogress.org/climate/2011/01/13/207334/science-kiehl-ncar-paleoclimate-lessons-from-earths-hot-past/

I could swear we've mentioned this to you before.

I know my conclusions make you uncomfortable, but your discomfort doesn't make them incorrect.

[hypergrove]

2. other factors?

Excellent - thank you for this; I'm sure I'll be a joy to be around tomorrow (not). I'm wondering though whether war, pestilence, droughts hurricanes and fires might spur a massive drop before 2030? Or fish-stocks that have practically disappeared over a period of several years this decade?

It'd be interesting to know the effect of zero-carbon usage, at given dates.
Thanks again for your analyses.

[AverageJoe90]

4. Here's my response.

I'm wondering though whether war, pestilence, droughts hurricanes and fires might spur a massive drop before 2030?

Barring an Apophis impact, full-scale nuclear war, or a megapandemic(all of which are very, very, unlikely btw), then no, no massive drop.

Thanks again for your analyses.

I'd rather stick to guys like Peter Sinclair and the Skeptical Science staff. They don't need hyperbole to tell us that this is something that urgently needs to be dealt with.

[Odin2005]

6. Tome for climate modification, I fear.

[GliderGuider]

7. Kick to make sure people see my error and apology nt