coral reefs doomed?
Alan E Strong
Alan.E.Strong at noaa.gov
Mon Sep 10 13:59:40 EDT 2001
Dear Ove, Bob, and others,
It seems about the right time to correct a misimpression that we spoke to at
Bali last October. Our Bali paper noted that NOAAs satellite SST data from
around the tropics were believed to have been indicating an alarming increase
(upward tendency hardly a trend!) over the past two decades
high as 0.5 deg C at 5 N latitude! A re-evaluation of these data, through a
program sponsored by NASA and NOAA, called Pathfinder has taken all the
year-to-year improvements in making correct measurements over that time interval
and reprocessed the data in an up-to-date and uniform fashion. More importantly,
in-situ SST data from all the drifting and fixed buoys available were utilized
to both validate and correct satellite calibrations on a regular basis. From
Pathfinder we now believe that we have a more accurate set of NOAA satellite SST
the best results for buoy comparisons are still seen when using
only those Pathfinder satellite SSTs made at night.
>From Pathfinder nighttime SST observations (Paper will be presented at the
upcoming Ocean Sciences AGU) it is seen that SSTs through most of the tropical
latitudes have not been rising but holding rather steady. In fact some regions
have been showing steady DECLINES in SST. We still are finding greater declines
in the southern hemisphere (reported at the Bali meeting) but even northern
tropical locations show decreases: e.g., region around Midway; the region known
as The Warm Pool both continue to trend downward during the 80s and 90s. Even
though much of the Indian Ocean experienced devastating bleaching from high SSTs
in the late 90s, this area is basically experiencing a downward SST tendency.
There are several regions that may be showing statistically significant
increases, but this final say will not be official until the Feb 2002 Ocean
Sciences meeting when we expect to have Pathfinder 1999 and 2000 SST data
fully incorporated. Regions that have been experiencing upward tendencies are:
American Samoa Fiji Cook Islands; some regions of the Caribbean (especially
eastern portions); Mexicans Pacific coast; Red Sea; Arabian Sea/Persian Gulf;
and possibly the extreme southern regions of GBR. There are other regions in
the northern Atlantic and Pacific, outside areas of interest to coral folks,
that show upward trends. These upward tendencies may be starting to show
effects of climate increases that, from the oceans standpoint seem to be mostly
noted at higher latitudes in the Northern Hemisphere
.see you at Oceans
A much scarier scenario is seen when the 1997/98 El Nino period is incorporated,
a scenario we believe that will be largely eliminated with the addition of 1999
and 2000 SST data. Any trends ending during such a significant event are
statistically flawed. What some are concerned about for the future of coral
reefs from the standpoint of temperature is what will El Ninos be like over the
next 50 years
So far I know of no reliable model with the answer to that
> -------- Original Message --------
> World coral reefs to die by 2050, scientist warns
> By Ed Cropley, Reuters
> Thursday, September 06, 2001
> GLASGOW, Scotland The world's coral reefs will be dead within 50 years
> because of global warming, and there is nothing we can do to save them, a
> scientist warned Wednesday.
> "It is hard to avoid the conclusion that most coral in most areas will be
> lost," Rupert Ormond, a marine biologist from Glasgow University, told a
> science conference. "We are looking at a loss which is equivalent to the
> tropical rain forests."
> Only the coral reefs in nontropical regions such as Egypt stand any chance
> of lasting beyond 2050, Ormond said, but even the days of the stunning
> marine parks of the Red Sea are numbered as sea temperatures continue to
> creep up.
> In the past, reefs have suffered from sediment buildup and the coral-eating
> crown-of-thorns starfish, whose numbers have exploded due to the
> over-fishing of their predators.
> Now the main threat to the delicate structures that harbor some of nature's
> most stunning creations comes from warmer seas, which cause coral bleaching.
> Microscopic algae that support the coral polyps cannot live in the warmer
> water, and the polyps, the tiny creatures who actually create the reefs, die
> off within weeks.
> Scientists agree the world's oceans are now warming at a rate of between one
> and two degrees Celsius every 100 years due to the increased amounts of
> greenhouse gases in the atmosphere which trap the sun's rays.
> But even if humans stopped pumping out greenhouse gases such as carbon
> dioxide tomorrow in a bid to halt the process, it would still be too
> late to
> save the reefs, Ormond said. "I don't know what can be done, given that
> there's a 50-year time lag between trying to limit carbon dioxide levels and
> any effect on ocean temperature," he told the conference, held by the
> British Association for the Advancement of Science.
> The implications stretch far beyond the death of the colorful coral
> structures themselves. The weird and wonderful eels and fish which inhabit
> the nooks and crannies will become homeless, and many species will die out.
> "We are looking at a gradual running down of the whole system. Over time,
> the diversity of coral fish will die," Ormond said.
> Humankind will also suffer directly as the dead reefs are eroded and
> shorelines that have been protected for the last 10,000 years face the wrath
> of the oceans without their natural defenses.
> In an age of relatively cheap scuba-diving holidays, this also means many
> developing countries in the tropics, such as Kenya or those in the
> Caribbean, face losing a major source of revenue.
> The only cause for optimism was that new coral reefs could start to emerge
> in colder waters such as the north Atlantic Ocean and Mediterranean Sea.
> Copyright 2001 Reuters
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**** <>< ******* <>< ******* <>< ******* <>< *******
Alan E. Strong
Acting Chief, Oceanic Research & Applications Division
Team Leader, Marine Applications Science Team (MAST)
NOAA/NESDIS/ORA/ORAD -- E/RA3
NOAA Science Center -- RM 711W
5200 Auth Road
Camp Springs, MD 20746-4304
Alan.E.Strong at noaa.gov
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