> First, there are energy balance considerations. If the planet (or > anything else) warms up, it radiates away more energy. Things don't just > heat up and warm down (much) by themselves. Variability is the flip-side > of sensitivity here, since a planet that varies by 0.3C in the absence > of any external forcing is likely to vary by rather a lot when it > actually *is* forced!
But the planet does cool/warm by 0.6C all by itself when comparing nearby monthly averages for world temperature. I must say this whole thread has got me thoroughly confused. I searched for Hasselman and red noise and got this http://www-pord.ucsd.edu/~rdavis/publications/Red_Noise.pdf I had to do some analyses of frequency spectra as (a minor) part of my PhD, but my skills there are a bit rusty. So maybe I don't get it, but they seem to dismiss the notion of regime change in the case of the PDO by arguing it could just be noise with a low frequency? And, if ocean currents, and things like systematic changes in Saharan dust storms and cloudiness, are to blame for noise on a 1-5 year cycle between peak and trough, if these were to persist for 30 years, they wouldn't have to be as strong, after all ocean heat capacity flattens out short term jumps (remember all the discussion of how quickly an instantaneous increase in aerosol forcing would lower temperatures). --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups Global Change ("globalchange") newsgroup. Global Change is a public, moderated venue for discussion of science, technology, economics and policy dimensions of global environmental change. Posts will be admitted to the list if and only if any moderator finds the submission to be constructive and/or interesting, on topic, and not gratuitously rude. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/globalchange -~----------~----~----~----~------~----~------~--~---
