January 17, 2005
One of the more interesting "Sky Is Falling" postulations made in recent years has been the claim that the apparently cooling stratosphere is masking observation of anticipated warming in the troposphere. Quaintly, such claimants point to satellite MSU (Microwave Sounding Unit) stratosphere data suggesting such cooling to try to invalidate satellite MSU troposphere data, data which obstinately declines to demonstrate the trend Big Warming requires to maintain the scare and nurture the cash cow.
One of the reasons suggested for stratospheric cooling is that more infrared (re-)radiation from the Earth is being trapped by increasing atmospheric carbon dioxide and is thus unavailable to warm the stratosphere (you are required to ignore any thought of saturation to believe this). Another, more plausible explanation would be reduced stratospheric ozone (ozone is a greenhouse gas) from whatever cause and the stratosphere is thus capturing less energy and cooling. Possible reasons for 'loss' of ozone are not addressed here but no, we are not staunch supporters of the Montreal Protocol either.
Typically, the cry at JunkScience.com is "Show me the data!" and, happily for our band of wandering skeptics, the required data is readily available here. Since most people exhibit signs of distress when faced with tabular data we have provided a representation in graphical format (linked from the thumbnail below). Two startling anomalies are obvious in the data, the stratospheric response to explosive volcanic eruptions of El Chichon in 1982 and Mt. Pinatubo in 1991. Although they are of limited value we know that people will ask, especially as they are not marked on the graph so, entire series trend value: y = -0.0038x + 0.5538 and first split 12/78 - 12/93 trend value: y = -0.0021x + 0.4581.
We've all heard the claims (repeatedly) that the Earth is currently hot and getting hotter. In fact, a quick sort on the GISTEMP near-surface amalgam shows the top 7 global mean temperatures since 1880 have occurred in the period following our Pinatubo shading. Logically then, if "global warming" (enhanced greenhouse) causes stratospheric cooling and 7 of the 11 years in our final trend split are the hottest years, at least since 1880, we expect to see stratospheric temperatures cooling, no? Let's look at the graph...
... uh-oh - that's not Big Warming's desired result is it. What could have gone "wrong?"
Perhaps the near-surface record is now so UHIE-corrupted that the planet wasn't really that warm? Possible but they won't go there because that would trample the enhanced greenhouse thing about increased infrared capture in the troposphere denying the stratosphere and causing cooling there (which is masking the warming in the tropospheric record - right?).
Recovery in the stratospheric ozone? Nope, that would upset too many fellow travelers because there'd be no need to continue attacking chlorine/bromine compounds as alleged ODS (Ozone Depleting Substances) - imagine a world where you couldn't get rid of so useful a compound as methyl bromide - unthinkable!
Hmm... a tough one. Big Warming seems to have [another] problem.
How long, do you suppose, before they come up with the old shell game: stratospheric cooling being masked by tropospheric warming?
No? Why not? Big Warming, the three-M coalition of Misanthropists, Miscreants and Misguided are certainly masters of the art of circular reasoning. The troposphere is really warming, despite what your lying eyes and empirical data tell you, it's just being masked by the cooling stratosphere - which you could see to be cooling except that cooling is being masked by tropospheric warming. Quod erat demonstrandum.
More for amusement than anything the two tracks prove, here then is the combination showing both the lower troposphere and lower stratosphere along with a few important influences noted.
Presenting data in this fashion does not help Big Warming's campaign since, absent obvious external factors, one track neither consistently mirrors nor mimics the other - not what we might expect if warming one cools the other.
We might surmise that components of Mt. Pinatubo debris increased ozone destruction, contributing significantly to stratospheric cooling as the atmosphere cleared following that event. It is interesting that there appears to be two step reductions in stratospheric temperature following both the explosive volcanic events that caused initial warming - that would not appear consistent with enhanced greenhouse-induced cooling since increase in atmospheric carbon dioxide has been more or less consistent over the period. We might surmise a lot of things but we find no support for Big Warming's contention though.
Obviously we're still having trouble with the "it'd be hotter if it wasn't cooled" thing.