PLEASE NOTE:
*
CCNet 111/2000 - 31 October 2000
--------------------------------
"If ISS succeeds over the next few years, and other small
and large
platforms are established in 10-20 years by other entities both
governmental and commercial, continuous human presence beyond
Earth
may become a perpetual state. As I type these words, these may be
the last
few moments in the history of this planet when all earthborn life
was
restricted to Earth itself. Building a permanent space station
may be THAT
significant, and is one more reason to wish the project well.
What
brought us this far is 'runway behind us' and arguments over
routes and
strategies is a subject for future historians. It's what ahead of
us
- if we're clever and bold enough - that needs concentration on
at this
hour."
-- Jim Oberg, 30
October 2000
"It must be tempting this week, especially for the
inhabitants of
Bognor Regis and Selsey, to believe that the weather is getting
more
extreme. It has already passed into folklore that global warming
means
wetter downpours, windier storms and drier droughts. But is it
true? Lots
of journalists and environmentalists say it is. Newsweek
predicted "more
floods, worse hurricanes" because of global warming. [...]
Of
course, journalists and environmentalists have a vested interest
in
claiming such a link, because weather leads to stories about
climate. To
persuade a journalist to quote him, an environmentalist needs to
say
something alarming; to persuade a news editor to run his story, a
reporter
needs to include such quotes. So there is an inherent bias: you
are
unlikely to read of anyone saying that nothing much has changed
and
that the latest storm has nothing to do with climate
change."
-- Matt Ridley, 31 October 2000
(1) JAPANESE SPACEGUARD TEAM DISCOVER LARGE APOLLO-TYPE ASTEROID
Duncan Steel <D.I.Steel@salford.ac.uk>
(2) EPOCHAL CHANGE IN HUMAN HISTORY
James Oberg <JamesOberg@aol.com>
(3) DOD FIREBALL DETECTION
Peter Brown <pbrown@julian.uwo.ca>
(4) DID ASTEROIDS SUPPLY EARTH'S WATER?
Sky & Telescope 29 October 2000
(5) LUNAR CRATER RAYS: ANCIENT OR MODERN?
Sky & Telescope, 27 October 2000
(6) LATEST RESEARCH SHOWS PACIFIC SEA LEVELS NOT RISING
SpaceDaily, 28 October 2000
(7) CURRENT EXTINCTION TURNS OUT TO BE A SLOW PROCESS
Andrew Yee <ayee@nova.astro.utoronto.ca>
(8) PANSPERMIA
Michael Paine <mpaine@tpgi.com.au>
(9) AND FINALLY: WEATHER AND CLIMATE ARE DIFFERENT THINGS
The Daily Telegraph, 31 October 2000
==============
(1) JAPANESE SPACEGUARD TEAM DISCOVER LARGE APOLLO-TYPE ASTEROID
From Duncan Steel <D.I.Steel@salford.ac.uk>
Dear Benny,
Few people yet seem to have noticed the discovery of a very large
Apollo-type asteroid on October 21st by the Japan Spaceguard team
at Bisei.
This has been designated 2000 UV13. For information see MPEC
2000-U34 at:
http://cfa-www.harvard.edu/mpec/K00/K00U34.html
This object has an absolute magnitude H=13.5, which would make it
between 5
and 12 km in size, depending on the albedo one assumes; see:
http://cfa-www.harvard.edu/iau/lists/Sizes.html
Looking down the list of Apollos at:
http://cfa-www.harvard.edu/iau/lists/Apollosq.html
I find only (1866)
Sisyphus with H=13.0 which appears to be brighter (and, one
assumes,
larger). (Note that 2000 UV13 is given as having H=13.3 on that
web page.)
On MPEC 2000-U34 it is stated that 2000 UV13 was discovered using
the 0.5-m
telescope at Bisei; David Asher tells me that in fact the
discovery was made
using the 0.25-m system there, which is noteworthy in itself.
In modelling the population of NEAs down to some set size, many
assumptions
need to be made, and they are not always valid. As Al Harris
pointed out at
the IAU General Assembly in August, to that time the discoveries
of NEAs
larger than a few kilometres in size represented 108% of the
total number
indicated by his modelling. I guess 2000 UV13 skews this
super-completeness
value still higher. But of course it may simply be a singular
object that
happened to have slipped through the fence until now.
Congratulations to the team at Bisei on their BIG discovery.
Duncan Steel
===========
(2) EPOCHAL CHANGE IN HUMAN HISTORY
From James Oberg <JamesOberg@aol.com>
Last Few Hours in History of Unmanned Space?
If ISS succeeds over the next few years, and other small and
large platforms
are established in 10-20 years by other entities both
governmental and
commercial, continuous human presence beyond Earth may become a
perpetual
state. As I type these words, these may be the last few moments
in the
history of this planet when all earthborn life was restricted to
Earth
itself. Building a permanent space station may be THAT
significant, and is
one more reason to wish the project well. What brought us this
far is
"runway behind us" and arguments over routes and
strategies is a subject for
future historians. It's what ahead of us -- if we're clever and
bold enough
-- that needs concentration on at this hour.
Jim Oberg
www.jamesoberg.com
Houston, Texas
October 30, 2000
===========
(3) DOD FIREBALL DETECTION
From Peter Brown <pbrown@julian.uwo.ca>
Fireball Detection
IR sensors aboard DOD satellites detected the impact of two day
time bolides
over the Czech Republic. The first occurred on 6 May 2000 at
11:54:52.545
UTC and the second on 10 May
2000 at 17:15:22.787 UTC. The 6 May object was first detected at
50.42
degrees North Latitude, 17.95 degrees East Longitude at an
altitude of
approximately 36 km. It followed a nearly flat trajectory,
inclined 2
degrees to the horizontal on a heading of 146 degrees. It was
last detected
at 49.64 degrees N, 18.76 degrees E at an altitude of
approximately 33 km.
The object was simultaneously detected by space based visible
wavelength
sensors operated by the DOE.
The observed peak intensity was 1.05 X 10^10 Watts/ster. The
total energy
was 2.5 X 10^10 Joules.
The 10 May object was first detected at 48.53 degrees N, 16.38
degrees E at
an altitude of approximately 55 km. It had a relatively steep
trajectory,
inclined 57 degrees to the horizontal on a heading of 113
degrees. It was
last detected at 48.49 degrees N, 16.53 degrees E, at
approximately 38 km
altitude. This object was also detected simultaneously by visible
wavelength
sensors operated by the Department of Energy. The peak intensity
was also
1.05 X 10^10 Watts/ster, but the total energy was a bit less at
1.9 X 10^10
Joules.
**************************************************************************
PLEASE NOTE THAT THIS SATELLITE BOLIDE RELEASE AND ALL PREVIOUS
SUCH RELEASES CAN BE FOUND ON THE WWW AT
http://phobos.astro.uwo.ca/~pbrown/usaf.html
*********************************************************************
Dr. Peter Brown
Assistant Professor
Meteor Physics Group
Department of Physics and Astronomy
University of Western Ontario
London, Ontario
N6A 3K7
Canada
http://phobos.astro.uwo.ca/~pbrown
Voice:1-519-661-2111 x86458
Fax:1-519-661-4085
email:pbrown@julian.uwo.ca
Meteor Astronomy Lab : 1-519-661-2111 x84744
Meteor Physics Lab : 1-519-850-2385
============
(4) DID ASTEROIDS SUPPLY EARTH'S WATER?
From Sky & Telescope 29 October 2000
http://www.skypub.com/news/news.shtml
Why is our planet so wet? This question has perplexed scientists
for
decades, because the Earth formed in an environment too hot for
water to
condense directly from the solar nebula. One long-held view was
that a swarm
of comets entered the inner solar system at the end of the
planets'
assembly, bombarding the terrestrial worlds roughly 4 billion
years ago
during what's termed the "late heavy bombardment."
Since comets contain lots
of water, they could easily have delivered oceans' worth of the
stuff to
Earth. However the theory has several flaws. Most importantly,
the ratio of
deuterium to hyrdrogen in cometary water is much higher than the
D/H ratio
in our oceans. And as yet there is no compelling explanation for
how and why
so many comets could have arrived in such a geologically brief
time (roughly
100 million years). Moreover, the Moon's cratering record can be
explained
by an abrupt falloff in the impact rate, rather than a late
pulse.
At an international meeting of planetary scientists last week, a
team of
dynamicists led by Alessandro Morbidelli and Jean-Marc Petit
(Nice
Observatory, France) suggested that primitive asteroids -- not
comets --
were the source of Earth's oceans. According to their model,
early in the
planetary-accretion process Jupiter had already grown so large
that its
gravitational force was altering the orbits of virtually
everything in the
region now known as the asteroid belt. At the time the belt was
densely
packed with planetary embryos and asteroids, many containing up
to 10
percent water, but in just a few tens of millions of years more
than 99
percent of these accretional leftovers had been cleared out. Some
were drawn
into Jupiter, others were ejected from the solar system, and more
still were
cast into the Sun.
Computer simulations by Morbidelli's team reveal that several of
the belt's
largest escapees should have collided with the nascent inner
planets. By
then Earth had become massive enough to keep most of the
collisional ejecta
from being lost to space, so the impactors contributed their
considerable
bulk to our planet's growth and supplied more than enough water
to fill its
oceans.
Meanwhile, about 5 percent of the asteroid belt's survivors ended
up in
"excited" orbits with large inclinations and
eccentricities. In the final
stages of planetary accretion, thousands of these objects rained
down on the
inner planets with velocities that averaged 30 kilometers (20
miles) per
second. Coming in so fast, they packed a tremendous wallop: on
the young
Moon, for example, even modest 400-meter objects blasted out
craters 10 km
(6 miles) across.
Comets are not entirely ruled out by this hypothesis. According
to
Morbidelli and Petit, perhaps one tenth of Earth's water could
have arrived
via dirty snowballs without skewing the D/H ratio too much.
Moreover, the
researchers note that if the late heavy bombardment was in fact a
sudden
pulse of colliding objects, rather than a gradually subsiding
storm, then
comets would likely have been the dominant source.
Copyright 2000, Sky & Telescope
================
(5) LUNAR CRATER RAYS: ANCIENT OR MODERN?
From Sky & Telescope, 27 October 2000
http://www.skypub.com/news/news.shtml
The bright, petal-shaped ray systems surrounding lunar craters
like
Copernicus and Tycho are more than fascinating telescopic
targets. Planetary
geologists use them as time markers to help establish the
sequence of lunar
history -- a chronology that relies in part on the belief that
rays surround
young craters but not old ones. Lunar material darkens with time
as the iron
in its minerals becomes less oxidized after exposure to space. So
once a
crater forms, its rays presumably fade to invisibility over
several hundred
million years.
But new results are challenging these long-held assumptions. A
team of
investigators led by B. Ray Hawke (University of Hawaii)
reassessed several
rayed lunar craters using data from the Clementine mission. They
judged the
rays' maturity using not just brightness as the sole criterion
but also
their iron and titanium content and the ratio of their color
intensity at
deep red and near-infrared wavelengths. They find that some rays
form when
bright highlands material is thrown from the impact site and
splashes onto
darker plains, as occurred around the 20-kilometer-wide crater
Lichtenberg.
Other ray systems arise from the plains themselves, because
chunks ejected
from the main crater stir up the surface on which they fall. The
bright
tails of Messier and Messier A are examples of recently exposed
mare
material.
Distinguishing between these two origins is critical to
determining a
crater's age, because Lichtenberg-type rays, which contain lots
of highlands
debris, will never darken completely. "We've assumed that
rayed craters are
all younger than about 800 million years," Hawke explains.
"But these
bright, mature ray systems could be 2, 2½, or even 3 billion
years old."
This has serious implications for how geologists decipher lunar
history, he
warns. If further work shows that many crater rays are extremely
old instead
of relatively young, the whole chronology of the Moon's surface
evolution
will need to be revised.
Copyright 2000, Sky & Telescope
=============
(6) LATEST RESEARCH SHOWS PACIFIC SEA LEVELS NOT RISING
From Space Daily, 28 October 2000
http://www.spacedaily.com/news/001028051438.nd4vw2r6.html
TARAWA, Kiribati (AFP) - October 28th, 2000 - The latest
scientific research
has shown Pacific Ocean sea levels are not rising, it was
announced
Saturday. Dr Wolfgang Scherer, director of Australias National
Tidal
Facility, told journalists covering the Pacific Islands Forum
here that data
gathered over the past nine years showed no evidence of sea
levels
increasing.
Under an Australian aid programme in association with the South
Pacific
Regional Environment Programme, automatic sea level and climate
observation
stations installed in 11 island countries had been feeding data
via
satellite back to his project base in Adelaide.
While there was mounting evidence of oceans warming to some
extent, he said,
no evidence existed of sea levels rising. Scherer said ocean
response times
to change were slow and could take hundreds of years.
"There are interactions between the atmosphere and oceans,
some of which we
understand and some we do not understand," he said.
"But we have no evidence
of sea levels rising."
FULL STORY at http://www.spacedaily.com/news/001028051438.nd4vw2r6.html
==============
(7) CURRENT EXTINCTION TURNS OUT TO BE A SLOW PROCESS
From Andrew Yee <ayee@nova.astro.utoronto.ca>
From The New York Times, 24 October 2000
[ http://www.nytimes.com/2000/10/24/science/24EXTI.html
]
Extinction Turns Out to Be a Slow, Slow Process
By ANDREW C. REVKIN
Scientists studying the planet's stressed-out rain forests,
rivers, reefs,
deserts and islands are increasingly confronting a new kind of
species --
the living dead. They are extant, but, in almost every way, are
already
extinct.
There is the Javan rhinoceros, reduced to 70 or so animals split
between a
tiny tract in Indonesia and another in Vietnam. There is the
golden Vizcacha
rat, which was recently discovered along one edge of a remote
salt flat in
northwest Argentina, just in time for its discoverers to see its
tiny
habitat being replaced by irrigated olive orchards.
Then there is the Hawaiian po'ouli. The number of these
black-masked
honeycreepers on the mountains of Maui has dropped from about 200
in the
1970's to just 3 today. Each inhabits a separate bit of
mountainside,
unaware it is not alone. Scientists do not know the sex of the
birds.
Such species, to borrow a bleak phrase from emergency-room
doctors, are
circling the drain. But they have been able to persist far longer
than the
experts studying them ever anticipated.
It turns out that many species on their last legs -- or wings or
bellies or
roots -- somehow find ways to adapt, albeit temporarily, to stark
changes in
their surroundings. Lonely hearts occasionally find each other to
bear a few
more offspring and so keep a unique genetic branch on the tree of
life
growing just a little bit longer.
They have come to symbolize the challenges faced by biologists
who are
studying and trying to save endangered species. Extinction has
proved to be
complex and sometimes excruciatingly slow, often tantalizing
conservationists with the prospect of bringing a fading species
back.
Some, like the Puerto Rican parrot, which has rebounded after
seeing its
population fall to just 12 birds, do seem capable of recovering.
But others
do not, even when they stare a biologist in the face.
Dr. Stuart L. Pimm, an extinction expert at Columbia University,
pointed to
the example of the po'ouli, whose last known members were tracked
down
several years ago by two of his postdoctoral students after three
years of
slogging through sodden forests.
"There is an extraordinary sense of loss when you see
wonderful animals and
plants and you know you may be the last people to see them,"
Dr. Pimm said.
"The po'ouli lingered below 10 or 20 individuals for years.
It's rather like
looking at some old, beloved relative who you know is simply not
going to
last another year or two. You don't know exactly when old uncle
Joe is going
to die."
In fact, the dogged quality of life in its end stages has come as
a slight
embarrassment to more than a few ecologists and conservation
biologists. Two
decades ago, in studies like the Carter administration's Global
2000 Report,
many experts were predicting that some 20 percent of the world's
species at
that time would be erased by now -- largely because of the
accelerating,
intensifying impact of humans on the landscape.
That may well be happening, but no one has proved it. In fact,
often as not
-- at least for conspicuous creatures like birds and mammals --
an isolated
few specimens tend to pop up just when scientists have decided
they cannot
possibly still exist.
There is a growing realization among ecologists that the endgame
for species
is not nearly as straightforward as it is portrayed in
mathematical models.
These predict extinction rates by crunching the density of
species in a
habitat, the size of the habitat and the rate at which it is
destroyed. The
discrepancy between theory and reality has led some biologists to
call for a
change in the way conservationists describe the extinction
process to the
public, and in the way that scientists study it.
A growing group of paleontologists and ecologists are calling for
a new push
to improve the data behind estimates and to stop making broad
statements
comparing current events to past cataclysmic extinction spasms
like the one
that erased the dinosaurs 65 million years ago. Those
comparisons, they say,
implied a level of clarity in the science that just does not
exist. They add
that scientists should emphasize that extinction itself happens
over a span
that is always going to be hard to measure or comprehend.
"In thinking about global extinction we've got to free
ourselves from this
human time scale," said Dr. John Alroy, an ecologist at the
National Center
for Ecological Analysis and Synthesis of the University of
California at
Santa Barbara. "To a species, a human lifetime is a little
flicker."
Human-caused extinctions are happening, Dr. Alroy said, and he is
one of
many biologists who are convinced that the pace is rapidly
accelerating. It
is just that this wave of biological losses is building but has
yet to break.
Only in retrospect, when some future culture -- human or
otherwise --
examines the fossil record, will the die-off be evident as a
substantial
pruning of the branches of the tree of life, he said. "For
the entire
remaining duration of life on earth," he said, "this
event we're responsible
for is clearly going to show up as a signature."
Instead of focusing on the nearly immeasurable moment when a
species ceases
to exist, he and other biologists say, science should focus
harder on the
forces that lead toward extinction -- the destruction or
fragmentation of
habitat, the introduction of invasive species, the appropriation
of water or
other vital resources.
Dr. Alroy is one of dozens of scientists who are essentially
trying to forge
a new discipline, extinction biology, incorporating ideas from
field
studies, genetics, ecology and paleontology.
They are seeking to know -- up close and in current time -- a
process that
formerly was almost exclusively studied by paleontologists
digging through
dusty layers of fossils. Mostly, they are trying to develop an
agenda to
improve the scientific underpinnings that could clarify why some
species
last and others do not.
Part of the difficulty in extending extinction science from the
past into
the present lies in figuring out how to reconcile the clues left
by past
comings and goings of species with those providing hints of what
may be
happening to existing species.
The main tool used by biologists to calculate current extinction
rates is a
longstanding formula called the species-area curve, which gives
an estimate
of species lost for a given area of habitat destroyed. Another is
population
viability analysis, which uses computer models to project trends
in a range
of conditions affecting isolated populations of a species and
calculates the
probability of long-time survival.
"Conservation biologists see changes in the environment and
estimate the
impact on species, while paleontologists see a record of change
in species
and try to match what environmental issues drove those
changes," said Dr.
David Jablonski, a paleontologist at the University of Chicago.
"The
fundamental problem in all this is the ways we estimate
extinction
intensities are totally different."
Many conservation biologists and groups have compared the current
extinction
episode with the five great dyings that punctuate the fossil
record, but Dr.
Jablonski and many paleontologists say the data are so different
-- and so
incomplete in both realms -- that there is no way to relate past
extinctions
to whatever is happening now.
Much more needs to be done to mesh the two disciplines, he said,
adding,
"Often, I'm the token paleontologist at conservation biology
meetings." That
has to change, he said.
A central challenge frustrating scientists studying the most
imperiled
species is that they are just nibbling at the edges of the
world's
biological diversity, a fact borne out in the vast gap between
the number of
species classified by science -- fewer than 2 million -- and the
latest
far-flung estimates of what is out there: anywhere from 7 million
to more
than 100 million, depending on who is counting.
The complexity of extinction, and the vastness of the biosphere,
have
prompted many scientists to call for a large increase in the
number of
biologists working both in the field and in museums or
laboratories to
clarify the relationships and characteristics of the planet's
myriad
endangered life forms.
Dr. Edward O. Wilson, an entomologist and ecologist at Harvard
University
who helped invent the current methods of estimating extinction
rates,
published an essay in Science last month calling for a large
effort to
improve mapping of biodiversity around the world.
"Right now we spend between $150 million and $200 million a
year in the
United States on studying global fauna and flora," Dr.
Wilson said. "That's
just dabbling. Compared to the magnitude of the problem, it's
chump change."
He and other biologists acknowledge that the need comes just as
the
explosion of advances in genetics and molecular biology is
attracting some
of biology's brightest young minds -- and a lot of the available
grants and
government money.
"If you say I want to go out and look for new mammals that
have never been
found, it's hard to get support," said Dr. Michael A. Mares,
a mammalogist
and director of the Sam Noble Oklahoma Natural History Museum at
the
University of Oklahoma. It was Dr. Mares whose team recently
discovered the
golden Vizcacha rat living on the edge of salt flats.
The nocturnal rodent eats a desert plant that is four times as
salty as sea
water. Dr. Mares discovered it while working far from the
"biodiversity hot
spots" that have become a prime focus of conservationists
lately. Even in
remote Argentinian deserts, pressure from agriculture is
intruding, he said.
While areas with the most species and the most threats are
clearly vital to
protect, he said, someone has to keep looking on the fringes.
"In this very isolated valley, you've got the possibility of
three or four
species and one genus disappearing with very little habitat
damage," he
said. "These are not charismatic species," he added.
"But they play an
important role in the ecosystem and do some very interesting
things."
Other biologists stress the importance, at the same time, of
improving
understanding of what is happening close to home, in places like
the woods
tucked amid American suburbs. Extinction and endangerment are not
limited to
faraway tropics, said Dr. David B. Wake, a biologist at the
University of
California, Berkeley, who divides his time between the cloud
forests of
Costa Rica, the suburbs of Southern California and the
stream-laced mountains of
the Pacific Northwest.
Dr. Wake, whose work in Costa Rica 15 years ago first hinted that
a
substantial die-off of frogs and other amphibians was taking
place, said
that salamanders tucked in moist pockets of woodlands in Southern
California
contained enormous genetic diversity.
Now, though, isolated populations are being quietly rooted out
with each
advance of roads and subdivisions, he said. "I've watched
this happen," he
said. "I've seen these tiny spots going out. A cougar or
bird couldn't exist
there, but salamanders can. The challenge for the future is not
that we're
losing all these species in the rain forest; we're losing them in
our
backyards."
Finally, some scientists say, for extinction biology to gain more
credibility, more work is needed to improve the basic taxonomic
data
determining just what is a species. Last year, Dr. Ross D. E.
MacPhee, the
curator of mammals at the American Museum of Natural History,
published an
analysis of the mammal extinctions in the 1996 Red List, a
quadrennial
roster of the planet's intensive care ward published by the World
Conservation Union, and found dozens of instances in which
species on the
list either were not extinct or were misidentified -- and also of
extinct
species that the list had missed. A separate analysis of data for
fish
extinctions produced similar findings.
Some biologists stress that concern over the current turmoil in
the natural
world should be tempered with the awareness that change,
sometimes a lot of
it -- including extinctions and new bursts of speciation -- is an
essential
part of the ferment of life on earth.
And life can prove quite tough and adaptable. Puerto Rico, which
lost 97
percent of its forests in the centuries following European
settlement, is
almost completely forested again, local scientists say, with a
mix of exotic
and native species. And sometimes species, with a little help, do
pull back
from the brink. The ginkgo tree was nearly extinct in its home
range of
China, preserved only on the grounds of a few monasteries. Now it
has spread
around the world and is ensconced in some rather unforgiving
ecosystems,
including Brooklyn.
Copyright 2000 The New York Times Company
===============
(8) PANSPERMIA
From Michael Paine <mpaine@tpgi.com.au>
I would like to make some comments about the 'panspermia' items
appears in
CCNet on 27 October.
Firstly, HOW LIFE CAN JUMP BETWEEN PLANETS discusses the finding
that
Martian meteorite ALH84001 was ejected from Mars without severe
heating from
the impact event. Jay Melosh showed theoretically how this could
occur over
a decade ago. I have likened it to shaking crumbs off a
picnic blanket (he may shudder at that). See
http://www.space.com/scienceastronomy/astronomy/rocks_fromspace_991108.html
and
http://www1.tpgi.com.au/users/tps-seti/swaprock.html
Secondly, the report of fossilized microorganisms in Russian
lunar samples
is very exciting but, despite extraordinary isolation efforts,
there could
be concerns about contamination. In a 1999 paper 'Contamination
of the
Murchison Meteorite' Andrew Steele and collegues write "The
fact that fungi
cold grow extensively on a coated sample within a sealed
SEM [scanning
electron microscope] box is ominous. It then brings into
doubt meteorite
storage methods and maybe the
protocols for meteorite storage should be looked at again."
The same
concerns might apply to storage of lunar sample. See links at
http://www1.tpgi.com.au/users/tps-seti/reading.html#ez8b
regards
Michael Paine
=============
(9) AND FINALLY: WEATHER AND CLIMATE ARE DIFFERENT THINGS
From The Daily Telegraph, 31 October 2000
http://www.dailytelegraph.co.uk/dt?ac=002830376029449&rtmo=lnFnQAot&atmo=HHHH22NL&pg=/00/10/31/do03.html
By Matt Ridley
IT must be tempting this week, especially for the inhabitants of
Bognor
Regis and Selsey, to believe that the weather is getting more
extreme. It
has already passed into folklore that global warming means wetter
downpours,
windier storms and drier droughts. But is it true?
Lots of journalists and environmentalists say it is. Newsweek
predicted
"more floods, worse hurricanes" because of global
warming. The Earth Island
Journal this year predicted "fiercer winds, deadlier floods,
longer
droughts". The Global Environmental Outlook 2000 claimed
that global warming
will "raise the incidence of extreme weather events,
including storms and
heavy rainfall". Greenpeace, Friends of the Earth and all
the usual suspects
have repeatedly linked global warming and an increase in extreme
weather
events.
Of course, journalists and environmentalists have a vested
interest in
claiming such a link, because weather leads to stories about
climate. To
persuade a journalist to quote him, an environmentalist needs to
say
something alarming; to persuade a news editor to run his story, a
reporter
needs to include such quotes. So there is an inherent bias: you
are unlikely
to read of anyone saying that nothing much has changed and that
the latest
storm has nothing to do with climate change.
Even the VIPs of global warming seem convinced of the link
between global
warming and extreme weather. Vice-President Al Gore asserts that
"the
portion of the annual rainfall and snowfall which falls in
one-time storm
events will go up". Sir John Houghton, head of the Met
Office, started his
book Global Warming with a description of Hurricane Andrew and
implied that
the frequency of tropical cyclones might increase by 50 per cent
if carbon
dioxide levels doubled.
Alas, there is no substantial factual basis to such claims.
Extreme weather
is showing either a slight negative trend, or none at all, or a
slight
positive trend, depending on what you measure and where, but, if
anything,
we are living through quiet times. The number of tropical storms
has risen
in the north Pacific, shown no trend in the south Pacific and
fallen in the
Indian and Australian region. In the Atlantic, the average annual
maximum
wind speed in cyclones has declined steadily since 1945.
"Overall, there is no evidence that extreme weather events
or climate
variability has increased, in a global sense, through the 20th
century,"
says the Intergovernmental Panel on Climate Change. The evidence,
says the
World Meteorological Organisation, "points to an expectation
of little or no
change in global frequency [of cyclones]". Both these
organisations believe
the evidence for man-made global warming, but admit that the
evidence for
more extreme weather is not there.
It is true that weather-related insurance claims have risen
exponentially in
recent years. Environmentalists are fond of citing Munich Re's
estimate that
pay-outs on natural catastrophes have increased nine times since
the early
1980s. But they omit to mention the company's explanation for
this, which is
that there are more people, with more material possessions and
more
insurance, in high-risk zones. Indeed, if Florida had been as
heavily
populated in the 1920s as it is today, the damage done by
hurricanes would
have been far worse then than it was in the 1990s.
In the 1970s, there was also a rush of stories in the press
linking extreme
weather to climate change: rain, storms and floods were all said
to be
getting worse. But in those days, the scare was global cooling.
The planet
was said by scientists and environmentalists to be heading into
an ice age.
How odd that we live in a Goldilocks climate that is so perfect
it would
generate worse weather if it cooled, and worse weather if it
warmed.
The truth is that weather and climate are different things, and
the link
between them is shrouded in mystery. Impatient with acts of God,
we embrace
those who offer causal explanations of storms, just as we fall
for those who
tell our horoscopes.
Copyright 2000, The Daily Telegraph
----------------------------------------
THE CAMBRIDGE-CONFERENCE NETWORK (CCNet)
----------------------------------------
The CCNet is a scholarly electronic network. To
subscribe/unsubscribe,
please contact the moderator Benny J Peiser <b.j.peiser@livjm.ac.uk>.
Information circulated on this network is for scholarly and
educational use only. The attached information may not be copied
or
reproduced for any other purposes without prior permission of the
copyright holders. The fully indexed archive of the CCNet, from
February 1997 on, can be found at
http://abob.libs.uga.edu/bobk/cccmenu.html
DISCLAIMER: The opinions, beliefs and viewpoints expressed in the
articles and texts and in other CCNet contributions do not
necessarily reflect the opinions, beliefs and viewpoints of
the moderator of this network.