Warming & Ozone: Sea Change?
you haven't seen this story in the local paper or on
tragedy-TV: Global warming may be about to slow down
dramatically, if not completely. Further, a considerable portion
of the warming of the last half of the 20th century may have
been a "natural" internal oscillation of the Pacific Ocean.
news comes from yet another blockbuster paper from the climate
group at Texas A&M University. Last year, as covered in
these pages, Gerry North and his colleagues demonstrated that
sulfate aerosols don't cool the planet very much after all.
That discovery disturbs most greenhouse apocalysts, especially
our more global friends at the United Nations, who rely on
sulfate aerosols to explain why the planet has warmed so little,
compared with what (bad) computer models say should have
happened. If sulfates aren't the reason, then it is likely
that the carbon dioxide warming effect is just plain
this week, Yangang Liu and Peter Daum calculated in Nature
that the cooling effect from sulfate-induced cloudiness, the
so-called "indirect sulfate effect" has been overestimated
by 10 percent to 80 percent, yet another nail in the coffin of
the global warming apocalypse.)
the most recent A&M shocker, Amy Bratcher and Benjamin Giese
show that the vaunted sudden warming of the mid-1970s, known as
"the great Pacific Climate shift," resulted when a warm pool
of subsurface water generated in the Southern Ocean finally
joatered to the top near New Guinea. Once this happens, currents
move the tepid stuff rapidly eastward, and the surface
temperature responds in a few years.
is important because about half of the warming of the last 50
years is contained in the sudden 1976–1977 shift, and
there's no model of human-induced warming that produces such
you would think, if humans didn't cause the mid-1970s shift,
then it's likely that there would be some other compensating
cooling in subsequent decades. Otherwise global temperatures
would progress up and up and up (or down and down and down) much
more enthusiastically than they do.
and Giese write:
possibility exists that some portion of the recent increase in
global surface air temperature is part of a naturally
oscillating system. Examples of such natural variations are
prominent in the tropical Pacific Ocean…A sudden change in the
climate of the tropical and north Pacific Ocean during 1976 has
been extensively documented…Recent work suggests that the
origin of this climate shift comes from the Southern Hemisphere
and may be part of a naturally oscillating climate pattern [emphasis
where's the cooling? It's right around the corner! Bratcher
and Giese show that a big pool of cold water, about the same
size and magnitude as the warm one that caused the 1976 shift,
is about to surface in the western Pacific. Their calculations
suggest that the cooling will become evident within the next few
years. Strictly speaking (something no one in the climate
business has any business doing), the cooling should start in
1. Red line: Subsurface water temperature in the Southern
Ocean. Blue line: Sea-surface temperature in the Central
Pacific, lagged by seven years. Forecast: Clearing and cooler!
your pals at WCR
wouldn't have the guts to write that paper, but if it's
right, temperatures will drop
about 0.2°C in the next few years.
a mess this could cause! Take away this factor from the roughly
0.5°C of the last 30 years, and finally admit that sulfate
aerosols are, at best, also-rans, and that leaves a greenhouse
warming rate of about 0.1° per decade. Given that the consensus
of most climate models (ironically, not verbalized by most
climate modelers) is
that once greenhouse warming starts, it takes place at a
constant rate, this gives a mere 1.0°C of warming for the
Bratcher and Giese bomb dropped in the midst of another shocker,
which is the amazing, disappearing ozone hole. Of course,
we've always maintained that "ozone hole" was a misnomer
and should more correctly be called the "late winter Antarctic
ozone depletion" (LWAOD) because it is most prominent only for
a few weeks of the year, and once the sun gets high enough in
the sky to bust up stratospheric oxygen molecules, most of the
turns out that to everyone's surprise, this year's edition
of the LWAOD is the smallest in 15 years, which isn't many
years after the LWAOD first became prominent.
scientists indicate that the cause of this year's weenie hole
is an unusually warm Antarctic stratosphere. WCR scientists would like to point out that greenhouse warming,
which takes place in the lower atmosphere, commands a
compensatory cooling of the stratosphere.
just have to wonder if the ozone and climate shift stories
aren't a bit related. Is the fact that the stratosphere has
suddenly warmed a result of the equally sudden appearance of the
big Pacific chill? Stay tuned.
1. Maximum size of the Antarctic ozone hole, 1980 to 2002.
and don't go crediting the Montreal Protocol on
ozone-depleting chemicals for this change—observed
concentrations of those compounds haven't dropped enough to
effect this year's change in stratospheric ozone. And never
credit the Kyoto Protocol on global warming for anything
having to do with climate, because it will never have a
detectable effect on anything except our economic well-being.
A., and B. Giese, 2002. Tropical Pacific decadal variability and
global warming. Geophysical
Research Letters, 29,
Y., and P.H.Daum, 2002. Indirect warming effect from dispersion
forcing. Nature, 419, 580–581.
G.R., and Q. Wu, 2001. Detecting climate signals using
space-time EOFs, Journal
of Climate, 14,