PNAS: AGW may have been overestimated by a factor of 2

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kramer
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PNAS: AGW may have been overestimated by a factor of 2

Post by kramer » Sat Feb 09, 2013 4:05 pm

Hmmm, does this suggest that the skeptics of 'how much warming was caused by human caused CO2' were right?...
Abstract

The observed global-warming rate has been nonuniform, and the cause of each episode of slowing in the expected warming rate is the subject of intense debate. To explain this, nonrecurrent events have commonly been invoked for each episode separately. After reviewing evidence in both the latest global data (HadCRUT4) and the longest instrumental record, Central England Temperature, a revised picture is emerging that gives a consistent attribution for each multidecadal episode of warming and cooling in recent history, and suggests that the anthropogenic global warming trends might have been overestimated by a factor of two in the second half of the 20th century. A recurrent multidecadal oscillation is found to extend to the preindustrial era in the 353-y Central England Temperature and is likely an internal variability related to the Atlantic Multidecadal Oscillation (AMO), possibly caused by the thermohaline circulation variability. The perspective of a long record helps in quantifying the contribution from internal variability, especially one with a period so long that it is often confused with secular trends in shorter records. Solar contribution is found to be minimal for the second half of the 20th century and less than 10% for the first half. The underlying net anthropogenic warming rate in the industrial era is found to have been steady since 1910 at 0.07–0.08 °C/decade, with superimposed AMO-related ups and downs that included the early 20th century warming, the cooling of the 1960s and 1970s, the accelerated warming of the 1980s and 1990s, and the recent slowing of the warming rates. Quantitatively, the recurrent multidecadal internal variability, often underestimated in attribution studies, accounts for 40% of the observed recent 50-y warming trend.

http://m.pnas.org/content/early/2013/01 ... 1110.short
And consider that in 2009, scientists said that CO2 only produced around 40% of the warming:
Those conversations led Gore to politically inconvenient conclusions in this new book. In his conversations with Schmidt and other colleagues at the beginning of the year, Gore explored new studies - published only last week - that show methane and black carbon or soot had a far greater impact on global warming than previously thought. Carbon dioxide - while the focus of the politics of climate change - produces around 40% of the actual warming.

http://www.guardian.co.uk/world/2009/no ... nt-climate
In summary, the new PNAS paper says that the amount of warming caused by humans putting colorless and odorless plant and tree fertilizer in the air should be about 50% of what's been measured and then adjusted and re-adjusted etc... And the 2009 comment by Gore said that CO2 only produces around 40% of warming because other human caused factors were causing warming.

So if I'm doing the math right (and if there is no mention of some of the warming caused by soot or black particles in the PNAS paper), a more reasonable estimate for the total warming caused by humans releasing plant and tree food in the air should be 50% * 40% = 20%. Put another way, of the amount of warming that we have had since 1900, only 20% of it may have been caused by human released CO2.

Assuming my math is correct, this much smaller amount of human CO2 caused warming of just 20% looks more reasonable to me.

Given that the temperature recored has been adjusted and readjusted and that there are now known temperature biases from thermometer placement issues, I think it's possible that the amount of CO2 warming is more like 10% to 15%, an amount that I would not be skeptical of.
“We should have been warned by the CFC/ozone affair because the corruption of science in that was so bad that something like 80% of the measurements being made during that time were either faked, or incompetently done.”

- Scientist James Lovelock

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kramer
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Re: PNAS: AGW may have been overestimated by a factor of 2

Post by kramer » Sun Feb 10, 2013 6:35 pm

Hmmm, I would have thought Fordama would have been all over this post with cries of "carbon cycle," you don't understand science," and denier!...
“We should have been warned by the CFC/ozone affair because the corruption of science in that was so bad that something like 80% of the measurements being made during that time were either faked, or incompetently done.”

- Scientist James Lovelock

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kramer
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Re: PNAS: AGW may have been overestimated by a factor of 2

Post by kramer » Tue Feb 12, 2013 7:14 pm

3 days since I created this post and still no comment by Fordama. He must be waiting for Cook's site to come up with a general response to the PNAS paper so he can copy and paste it...
“We should have been warned by the CFC/ozone affair because the corruption of science in that was so bad that something like 80% of the measurements being made during that time were either faked, or incompetently done.”

- Scientist James Lovelock

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Re: PNAS: AGW may have been overestimated by a factor of 2

Post by Wabash » Wed Feb 13, 2013 5:45 am

Did you know that Costco sells aluminum foil in bulk?
They told me if I voted for Hillary Clinton the president would be emotional, impulsive, and unpredictable. They were right. I voted for Hillary Clinton and got a president that is emotional, impulsive, and unpredictable.

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Re: PNAS: AGW may have been overestimated by a factor of 2

Post by kramer » Wed Feb 13, 2013 6:58 am

Wabash wrote:Did you know that Costco sells aluminum foil in bulk?
Is that were you go to get your aluminum to make your tin foil panties?
“We should have been warned by the CFC/ozone affair because the corruption of science in that was so bad that something like 80% of the measurements being made during that time were either faked, or incompetently done.”

- Scientist James Lovelock

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Re: PNAS: AGW may have been overestimated by a factor of 2

Post by MDDad » Wed Feb 13, 2013 9:14 am

Wabash wrote:Did you know that Costco sells aluminum foil in bulk?
Did you know they also sell tampons in bulk?

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kramer
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Re: PNAS: AGW may have been overestimated by a factor of 2

Post by kramer » Wed Feb 13, 2013 4:40 pm

4 days and still no comment from Fordama... Wonder why?
“We should have been warned by the CFC/ozone affair because the corruption of science in that was so bad that something like 80% of the measurements being made during that time were either faked, or incompetently done.”

- Scientist James Lovelock

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kramer
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Re: PNAS: AGW may have been overestimated by a factor of 2

Post by kramer » Fri Feb 15, 2013 8:12 am

6 days and still no comment by Fordama...
“We should have been warned by the CFC/ozone affair because the corruption of science in that was so bad that something like 80% of the measurements being made during that time were either faked, or incompetently done.”

- Scientist James Lovelock

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kramer
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Re: PNAS: AGW may have been overestimated by a factor of 2

Post by kramer » Mon Feb 18, 2013 5:19 pm

9 days now and still no comment by Fordama...
“We should have been warned by the CFC/ozone affair because the corruption of science in that was so bad that something like 80% of the measurements being made during that time were either faked, or incompetently done.”

- Scientist James Lovelock

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kramer
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Re: PNAS: AGW may have been overestimated by a factor of 2

Post by kramer » Fri Feb 22, 2013 5:15 pm

Hmmm, 13 days and still no comment by Fordama, the expert on carbon cycles...
“We should have been warned by the CFC/ozone affair because the corruption of science in that was so bad that something like 80% of the measurements being made during that time were either faked, or incompetently done.”

- Scientist James Lovelock

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kramer
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Re: PNAS: AGW may have been overestimated by a factor of 2

Post by kramer » Mon Mar 04, 2013 10:22 am

Almost a month and still no comment from Fordama...

Maybe he needs a little help:
Image
“We should have been warned by the CFC/ozone affair because the corruption of science in that was so bad that something like 80% of the measurements being made during that time were either faked, or incompetently done.”

- Scientist James Lovelock

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Re: PNAS: AGW may have been overestimated by a factor of 2

Post by Vilepagan » Mon Mar 04, 2013 6:42 pm

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