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Reader (and Statistician) Jan Galkowski’s Quick Primer on CO2 and Climate Change

This weekend’s open thread here on AB produced an awesome post by reader, statistician and obvious genius Jan Galkowski on the significance of last week’s report on the level of CO2 now in the atmosphere.  Here’s part of the thread, including Mr. Galkowski’s post:

Rjs / May 11, 2013 4:54 am

in case you missed it, yesterday we breached 400 parts per million of atmospheric carbon dioxide…

all you need to know in just one chart

Sammy / May 11, 2013 3:54 pm

rjs,

Don’t fall for the scare tactics. The y axis scale on your graph is “parts per million.” So we’ve gone from 300 max parts per million, to 400 parts per million. Or .0003 to .0004 percentage CO2. This is statistically insignificant. Plus, as Jack pointed out, there “little correlation with global temperature.”

This graph backs up Jack’s point over a longer time frame; and also shows that we are historically at a low in atmospheric CO2:

Sammy / May 11, 2013 3:54 pm

rjs,

Don’t fall for the scare tactics. The y axis scale on your graph is “parts per million.” So we’ve gone from 300 max parts per million, to 400 parts per million. Or .0003 to .0004 percentage CO2. This is statistically insignificant. Plus, as Jack pointed out, there “little correlation with global temperature.”

This graph backs up Jack’s point over a longer time frame; and also shows that we are historically at a low in atmospheric CO2:

http://www.bing.com/images/search?q=CO2+over+time&FORM=HDRSC2&&id=F13D874C4502CF62C6C7A3A8DB2764DBC4C2E038&selectedIndex=1#view=detail&id=F13D874C4502CF62C6C7A3A8DB2764DBC4C2E038&selectedIndex=0

Jan Galkowski / May 12, 2013 2:52 pm

@Sammy,

Surely you’ll agree the argument that materials in systems are safe as long as their concentrations are small is erroneous. There are many examples where tiny amounts will derail proper operation.

But, to your specific point, the fact that CO2 concentration is, as Richard Alley calls it, The Biggest Control Knob of Earth’s climate is due to a simple confluence of [t]hree physical facts.

First, blackbody radiation from a body at Earth’s temperature happens to have the bulk of its outgoing radiation in the region of the infrared spectrum between 400 per cm and 1000 per cm.

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Second, CO2 happens to have a broad absorption between 550 per cm and 750 per cm.

Third, CO2 happens to resonate strongly at 667 per cm and, when it goes to ground state, reemits photons with frequencies very close to that. CO2′s cross-section for 667 per cm photons is very high. Thus, a stray photon at 667 per cm will in all likelihood be reabsorbed by another CO2 molecule.

This means about 2/3 of the radiation in the 550-750 per cm band gets captured by CO2, and the stronger the concentration, the more thorought the lasing effect of emission and reabsorption.

The net of this is that about 1.8 Watts per square meter are re-radiated from CO2 in the lowest 100 meters of atmosphere all around the planet. 1.8 Watts per square meter times the area of the Earth is about 690 Terawatts. That energy has to go somewhere, and does, boosting convection in atmosphere and oceans, as well as being conveyed in the water evaporation and condensation cycle, which essentially serves as a heat pump. Some goes into deep ocean, raising its temperature and weakening its ability to absorb CO2.

The greater differences in energy density, as always, demand equalization, so the poles warm more, percentagewise, than the tropics and intermediate lattitudes. This 690 Terawatts increases to 2000 Terawatts at 700 ppm CO2.

There is no trending or paleoclimate evidence needed to establish this. This is simple physics. It would be truly remarkable if 690 Terawatts of additional forcing had no effects upon Earth weather.

They who might be interested in more details regarding this should monitor my blog,

http://hypergeometric.wordpress.com

where a 4-part lecture describing these mechanisms and the reason we know atmospheric CO2 increases are due to people’s actions, namely fossil fuels, will be described in detail, probably some time this summer.

Thanks.

Those among us who can do such things as add and subtract will have an easier time understanding the specifics of Mr. Galkowski’s post than those among us (okay, the one among us) who cannot.  But even those of us in the latter category can understand the gist of this.  And its importance.  (Trust me on that.)

 

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Hurricane Sandy and climate change

Reader Jan Galkowski sends this caution about promoting Hurricane Sandy as the result of climate change.  The following is taken from an e-mail to me yesterday:

There’s a lot being written about Hurricane Sandy in connection with climate change. It is likely that this hurricane was exacerbated by human induced climate change, notably the excessively warm waters off New England, but it is not scientifically correct to say the hurricane or its merging to become a nor’easter were caused by climate change. It is possible that the blocking high over Greenland contributed to that, however the attribution is dilute, if present.

Andy Revkin in the New York Times has a nice summary of the current science.

Although we know all is affected by greater energy on the planet, the fraction of Sandy’s fury attributable is perhaps 10%. Thus, comments like the following from 350.org are simply incorrect, and are misleading:

It’s as out of kilter as the melting Arctic or the acidifying ocean. And if there were any poetic justice, it would be named Hurricane Chevron or Hurricane Exxon, not Hurricane Sandy.

The ends do not justify the means.
If there’s something to be learned by this experience, it is that climate change is expanding and enlarging the oceans by thermal effects, and eventually by ice mass melting, both through displacement and gravitational effects. Eventually, common nor’easters will suffice to breach Battery Park walls and drown barrier islands. And there may be surprises in store as well.

As some of you have seen, I myself have done a calculation showing that the frequency of out of season hurricanes has increased since the late 19th century. That increase is statistically significant, although it may not be enough for everyone to notice.

Despite the great need to move policy towards a global economy that grows without more material consumption, which I very much agree with, distorting the facts destroys trust and disturbs the healthy ecosystem of scientific funding and research. It is also unethical.

It may be inconvenient that people are not moved by reason as much as by fear. But that is their choice, even if they suffer the consequences. It’s the responsibility of science to educate and be principled, even if we know that delay implies additional cost, additional deaths. It will also be the responsibility of science to tell policymakers and people that certain aspects of climate change are no longer reversible in any time frame that makes political or economic sense, and the longer we wait, the more of that kind of thing there will be.
I ask your collective understanding of this matter, and draw your attention to what will be the increasing problem of mitigating rather than preventing climate-related risks, as they are described in the SREX report from the IPCC. (Revkin alludes to this at his page.) 

Thanks. Hope everyone’s healthy and safe.
– Jan

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