Feedback governing climate change

A very interesting and well-written article on one aspect of our climate -- feedback. The Anthropogenic Global Warming folks consider that there is positive feedback. The Earth warms, more water vapor comes into the atmosphere trapping more infrared radiation causing the Earth to warm even more. This idea has their panties in a bunch and is the cause for the hoopla and sub-prime science. Today, at Watts Up With That, Anthony has a guest post from professor Richard Lindzen, PhD (Alfred P. Sloan Professor of Meteorology, Department of Earth, Atmospheric and Planetary Science, MIT) with observational data that implies the positive feedback model is a false one and that there is a very large and very observable negative feedback driving our climate:
Lindzen on negative climate feedback

Simplified Greenhouse Theory
The wavelength of visible light corresponds to the temperature of the sun�s surface (ca 6000oK). The wavelength of the heat radiation corresponds to the temperature of the earth�s atmosphere at the level from which the radiation is emitted (ca 255oK). When the earth is in equilibrium with the sun, the absorbed visible light is balanced by the emitted heat radiation.

The basic idea is that the atmosphere is roughly transparent to visible light, but, due to the presence of greenhouse substances like water vapor, clouds, and (to a much lesser extent) CO2 (which all absorb heat radiation, and hence inhibit the cooling emission), the earth is warmer than it would be in the absence of such gases.

The Perturbed Greenhouse
If one adds greenhouse gases to the atmosphere, one is adding to the �blanket� that is inhibiting the emission of heat radiation (also commonly referred to as infrared radiation or long wave radiation). This causes the temperature of the earth to increase until equilibrium with the sun is reestablished.

For example, if one simply doubles the amount of CO2 in the atmosphere, the temperature increase is about 1�C.

If, however, water vapor and clouds respond to the increase in temperature in such a manner as to further enhance the �blanketing,� then we have what is called a positive feedback, and the temperature needed to reestablish equilibrium will be increased. In the climate GCMs (General Circulation Models) referred to by the IPCC (the UN�s Intergovernmental Panel on Climate Change), this new temperature ranges from roughly 1.5�C to 5�C. The equilibrium response to a doubling of CO2 (including the effects of feedbacks) is commonly referred to as the climate sensitivity.
Dr. Lindzen delivers the money quote:
From 1985 until 1989 the models and observations are more or less the same � they have, in fact, been tuned to be so. However, with the warming after 1989, the observations characteristically exceed 7 times the model values. Recall that if the observations were only 2-3 times what the models produce, it would correspond to no feedback. What we see is much more than this � implying strong negative feedback. Note that the ups and downs of both the observations and the model (forced by observed sea surface temperature) follow the ups and downs of temperature (not shown).
The 200+ comments are well worth reading as well...

January 2021

Sun Mon Tue Wed Thu Fri Sat
          1 2
3 4 5 6 7 8 9
10 11 12 13 14 15 16
17 18 19 20 21 22 23
24 25 26 27 28 29 30
31            

Environment and Climate
AccuWeather
Cliff Mass Weather Blog
Climate Depot
Ice Age Now
ICECAP
Jennifer Marohasy
Solar Cycle 24
Space Weather
Watts Up With That?


Science and Medicine
Junk Science
Life in the Fast Lane
Luboš Motl
Medgadget
Next Big Future
PhysOrg.com


Geek Stuff
Ars Technica
Boing Boing
Don Lancaster's Guru's Lair
Evil Mad Scientist Laboratories
FAIL Blog
Hack a Day
Kevin Kelly - Cool Tools
Neatorama
Slashdot: News for nerds
The Register
The Daily WTF


Comics
Achewood
The Argyle Sweater
Chip Bok
Broadside Cartoons
Day by Day
Dilbert
Medium Large
Michael Ramirez
Prickly City
Tundra
User Friendly
Vexarr
What The Duck
Wondermark
xkcd


NO WAI! WTF?¿?¿
Awkward Family Photos
Cake Wrecks
Not Always Right
Sober in a Nightclub
You Drive What?


Business and Economics
The Austrian Economists
Carpe Diem
Coyote Blog


Photography and Art
Digital Photography Review
DIYPhotography
James Gurney
Joe McNally's Blog
PetaPixel
photo.net
Shorpy
Strobist
The Online Photographer


Blogrolling
A Western Heart
AMCGLTD.COM
American Digest
The AnarchAngel
Anti-Idiotarian Rottweiler
Babalu Blog
Belmont Club
Bayou Renaissance Man
Classical Values
Cobb
Cold Fury
David Limbaugh
Defense Technology
Doug Ross @ Journal
Grouchy Old Cripple
Instapundit
iowahawk
Irons in the Fire
James Lileks
Lowering the Bar
Maggie's Farm
Marginal Revolution
Michael J. Totten
Mostly Cajun
Neanderpundit
neo-neocon
Power Line
ProfessorBainbridge.com
Questions and Observations
Rachel Lucas
Roger L. Simon
Samizdata.net
Sense of Events
Sound Politics
The Strata-Sphere
The Smallest Minority
The Volokh Conspiracy
Tim Blair
Velociworld
Weasel Zippers
WILLisms.com
Wizbang


Gone but not Forgotten...
A Coyote at the Dog Show
Bad Eagle
Steven DenBeste
democrats give conservatives indigestion
Allah
BigPictureSmallOffice
Cox and Forkum
The Diplomad
Priorities & Frivolities
Gut Rumbles
Mean Mr. Mustard 2.0
MegaPundit
Masamune
Neptunus Lex
Other Side of Kim
Publicola
Ramblings' Journal
Sgt. Stryker
shining full plate and a good broadsword
A Physicist's Perspective
The Daily Demarche
Wayne's Online Newsletter

About this Entry

This page contains a single entry by DaveH published on March 31, 2009 5:05 PM.

Life Magazine was the previous entry in this blog.

The Corn Lobby reads blogs is the next entry in this blog.

Find recent content on the main index or look in the archives to find all content.

Monthly Archives

Pages

OpenID accepted here Learn more about OpenID
Powered by Movable Type 5.2.9