Posts tagged ‘Stefan Constant’

## I Can't Help But Laugh

I found this conjured up a terribly funny image in my mind.  JunkScience has a challenge to climate journalists to try the math to test for themselves whether current global warming estimates make any sense.  The challenge per se is not funny, but the picture of a journalist... well, read the challenge first:

We believe climate
models are programmed with excessive climate sensitivity based on a
flawed understanding of past ice ages. Moreover, climate models wrongly
magnify potential warming to accommodate positive feedback mechanisms
while comparison with empirical measure shows negative feedback dominates, reducing warming experienced to about half theoretical values.

The challenge is for you to actually check the numbers -- see for yourselves whether we are wrong or not. Look up Stefan's Constant or just use 5.67 x 10-8
(close enough for our purpose but look it up to be sure). The textbook
derivation of globally averaged greenhouse, using Stefan's Constant,
evaluates to roughly 33 °C and 150 Wm-2. The IPCC Third Assessment Report alt: Third Assessment Report (Equation 6.1) states: "The climate sensitivity parameter (global mean surface temperature response Î”Ts to the radiative forcing Î”F) is defined as: Î”Ts / Î”F = Î»." A blackbody-equivalent Earth climate sensitivity parameter (Î») would be 33 / 150 = 0.22 °C per Wm-2. Real world measures (here) indicate Earth responds with only half the efficiency of a blackbody with a lambda (Î») value of just 0.1 °C per Wm-2.

Now use it to check the assertion: "Global climate forcing was about 6 1/2 W/m2
less than in the current interglacial period. This forcing maintains a
global temperature difference of 5 °C, implying a climate sensitivity
of 3/4 ± 1/4 °C per W/m2.
" Either consult your texts for Earth's temperature in Kelvin and any other numbers you need or see the numbers we've used here. Off you go -- we'll wait. If you can show us where we're wrong we'll retract and correct.

Can anyone out there picture your favorite journalist trying to do this?  Many journalists followed the tried-and-true career path of:  Avoid math altogether --> Become an English major --> Become a journalist as an alternative to playing the guitar in subway stations.  Who else would love to see Maureen Dowd taking on this analysis?