12 - 'Doubled CO2 means just 1.64 degrees of warming...' or maybe not.
Channel: potholer54
Date: 2010-12-15

Last week a paper by researchers at NASA's Goddard Institute for Space Studies led to sensational headlines that the Earth will only warm by as much as 1.64 degrees centigrade -- in a couple of centuries. Sound too good to be true? Of course it does. 

I've put this video together faster than I normally would because the myth has already gone viral. But it's so easy to spot the flaws you have to wonder why people who call themselves "skeptics" aren't skeptical enough to check even the most basic facts. 

CORRECTION:
Cbrhawk1 points out an error at around 3:15. He writes: "[Potholer] applies a subtractive 0.26C to the 4.5C estimate of the IPCC rather than properly applying the feedback to the formula." My response: The paper doesn't show how to apply the formula to other models, which is why I subtracted the 0.26 degC figure directly. However, I agree with Cbrhawk1 that it is not that simple, because higher temperatures would presumably lead to higher evapotranspiration rates. If we apply the figure pro-rata, then warming of 4.5 degrees would be reduced to 3.9 degrees.
    I have no argument with that at all; evapotranspiration is a negative feedback, and the paper shows that it is greater than previously estimated. The point of this video is to debunk the absurd conclusion that global temperatures are only set to rise by 1.64 degrees because of evapotranspiration. The focus of the study was not to determine global temps but to quantify the negative feedback effects of evapotranspiration.  Since the model started with a low warming figure, it resulted in a low warming figure when evapotranspiration was plugged in. Had the model started with a higher warming figure, it would have resulted in a higher warming figure when evapotranspiration was plugged in.  

SOURCES:

Original myth published in:
http://www.theregister.co.uk/2010/12/08/new_model_doubled_co2_sub_2_degrees_warming/

"'Greener' Climate Prediction Shows Plants Slow Warming"
NASA press release
http://www.nasa.gov/topics/earth/features/cooling-plant-growth.html

Original paper:
"Quantifying the negative feedback of vegetation to greenhouse warming: A modeling approach"
L. Bounoua et al, Geophysical Research Letters, Dec 2010

Bio of Lewis Page:
http://www.guardian.co.uk/profile/lewis-page

Mauna Loa CO2 growth data:
http://www.esrl.noaa.gov/gmd/ccgg/trends/

Contributions to accelerating atmospheric CO2 growth
from economic activity, carbon intensity, and
efficiency of natural sinks
-- J. Canadell, Proceedings of the National Academy of Sciences 2007

"Probabilistic Forecast for 21st Century Climate Based on Uncertainties in Emissions (without Policy) and Climate Parameters"
-- A.P. Sokolov et al, MIT 2009

Myth from the Register repeated:
http://www.openyoureyesnews.com/2010/12/14/new-nasa-model-doubled-co2-means-just-1-64%C2%B0c-warming/

...and again...
http://www.sott.net/articles/show/219487-New-NASA-model-Doubled-CO2-means-just-1-64C-warming

...and again...
http://www.climatedepot.com/a/9045/New-NASA-model-Doubled-CO2-means-just-164degC-warming-Previous-models-failed-to-properly-account-for-an-important-cooling-factor-which-will-come-into-play-as-CO2-levels-rise

...and again...
http://alethonews.wordpress.com/2010/12/11/new-nasa-model-doubled-co2-means-just-1-64%C2%B0c-warming/

...and again...
NASA Peer-Reviewed Study Finds Low Sensitivity To CO2 Doubling: The UN's IPCC Global Warming Science Is Imploding
http://www.c3headlines.com/are-leftistsliberal-elites-corrupt-stupid-hypocritical/

...and again...
New NASA model: Doubled CO2 means just 1.64°C warming
http://www.climatechangedispatch.com/home/8241-new-nasa-model-doubled-co2-means-just-164dc-warming

...and again...
NASA Peer-Reviewed Study Finds Low Sensitivity To CO2 Doubling: The UN's IPCC Global Warming Science Is Imploding
http://www.c3headlines.com/2010/12/nasa-peer-reviewed-study-finds-low-sensitivity-to-co2-doubling-the-uns-ipcc-global-warming-science-i.html

...and again...
Greenhouse Gasses Aren't Going To Be A Problem For Centuries Say Scientists From NASA
http://rightwingnews.com/2010/12/greenhouse-gasses-arent-going-to-be-a-problem-for-centuries-say-scientists-from-nasa-wait-what/

"Recent decline in the global land evapotranspiration trend due to limited moisture supply"
-- M. Jung et al, Nature, October 2010