Another Dark Little Corner

moon phases

Started this before change to "New Blogger", as backup in case of trouble with digiphoto blog "In a Small Dark Room", or rants & links blog "Hello Cruel World" . Useful - at one stage Dark Room was there, but like the astrophysical Dark Matter, we could't see it ... better now, but kept Just In Case.

Your ABC

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There is nothing. There is no God and no universe, there is only empty space, and in it a lost and homeless and wandering and companionless and indestructible Thought. And I am that thought. And God, and the Universe, and Time, and Life, and Death, and Joy and Sorrow and Pain only a grotesque and brutal dream, evolved from the frantic imagination of that same Thought.
Mark Twain (letter to Joseph Twichell after his wife's death)
[me, on a bad day]

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When the Hubble Space Telescope rocketed into orbit aboard the Shuttle Discovery on April 25, 1990, the world of astronomy was forever changed for the better
Anniversary Feature

Four Famous Photos

Register for MyNASA and get the NASA information you want. As a member you can customize your MyNASA page with the NASA channels and content that interests you. Members can also bookmark articles and features throughout the portal for quick access during future visits.

In German ...

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Cats, Butterfly weight, Haiku Earrings, Schiavo subtext, etc  
How not to get a good nights sleep
New rule: before strapping on the CPAP mask, check to make sure that no cat has thrown up in it.

Sleeping Cats
... was experimenting with sleeping next to me last night, so I didn't get much sleep ...

Having seen RESIDENT EVIL 2
... It's not a horror film. It's a video game film. You can always hit replay on a video game so there's no element of tension, no possibility of permanent loss.
I've proposed what I call "Less Virtual Than It Looks Reality" games (in which the dangers to the character in the game are translated into real danger to the player) to various companies but they all lacked my visionary nature. They call it "negligent homicide" but I call it "artistic vision."

In breaking news: Fox announces PONTIFF!
CNN is reporting that Fox has signed a deal with the Vatican for the next big reality show, PONTIFF!. This will use the format of shows like SURVIVOR and THE APPRENTICE, mapped onto the selection process for the next Pope.
April 11, 2005
Andrea Dworkin Has Died
Vanessa cardui
I watch the painted ladies flying north.
Hundreds of the butterflies pass me in any five-minute period. They’ve been headed north for some weeks, nourished by a spectacular
growth of annual flowers in the Mojave and deserts south ... It's really rather impressive. This blizzard of orange and black crepe crossing mountains, desert valleys, going from country to country, no luggage nor passport, orange and black wings thinner than crepe and fueled by tiny sips of flower, and they're moving faster than I can run. Each is just slightly more substantial than a thought, maybe a tenth of a gram of chitin and water and light. But probably ten thousand butterflies will pass me on my hike, a kilogram of flying stained glass shards. My hike covers five and a half miles. Extrapolate from there: many tons of butterflies are moving north in California today.
Butterflies hate cameras, I find. With the lens stowed safely in my pack the painted ladies linger in my gaze ...
When stealth and slyness fail, a cheating hunter uses bait. I park myself near a black sage in flower ...

Philadelphia Flower Show, 2005. Photos - very large.

Haiku Earrings
The concom got Elise Matthesen to come out and sell her jewelry. On Sunday she did haiku earrings. This is the process:

Elise lays out a bunch of small earrings on her table.
You pick out one or a pair and bring it to her.
She gives you a title.
You write the haiku that has that as the title.
You put the haiku where the earrings were.
Now you own the earrings.
Optionally you grant her the right to reproduce your haiku in a chapbook and/or a card to be strung on a necklace.

My earrings had two beads: the upper was an oval with pointed ends, a shiny yellow, with a picture of an oval-shaped leaf, strung through one
end; the lower a clear blue faceted ball.

I took them to Elise. She asked me, "Silly or serious?" (I found out later that she had asked someone else, "Ancient or modern?".) I chose serious, and received 'The Price of Immortality'.

The Price of Immortality

Yellow leaves in blue
Water are carried away
And never touch me.

I read this to Elise. She smiled. "Yes," she said. "That's the haiku that goes in that place."

Farthing, Jo Walton -- A beta read, gloat gloat. This is supposed to be out sometime this year from Tor Forge, but I haven't seen it on their
schedule yet. A mystery novel set in an alternate timeline where Rudolf Hess actually managed to make peace between Nazi Germany and the UK. Very powerfully written, one of the best books I read all year.

David Scott Marley

Debbie N.
10:28 am - The New Yorker killed Terri Schiavo
Apparently, I'm not allowed News/2005/04/04/981625-sun.html to make public entries about the thing I really want to be talking about today (is blogging journalism? is a livejournal a blog? my head hurts.), so I'll take on the New Yorker instead. One of the things that's struck me about all of the verbiage devoted to the Terri Schiavo case is that there's been very little mention of how she was reduced to a permanent vegetative state in the first place. Amidst the discussions from both left and right about whether a brain cavity filled with spinal fluid actually qualified as "life," why is "look, bulimia can kill you!" not being shouted from every rooftop? As one of the few publications that actually mentions the disease in conjunction with Schiavo, the esteemed New Yorker might have an answer for us. Hendrik Hertzberg writes, in the column "The Talk of the Town" for the April 4th issue (emphasis mine):
Terri Schiavo was born on December 3, 1963, near Philadelphia, the first of three children of Robert and Mary Schindler.
As a teenager, she was obese -- at eighteen, she weighed two hundred and fifty pounds -- but with diligence she lost a hundred pounds, and by the time she married Michael Schiavo, in 1984, she was an attractive and vivacious young woman. By the end of the decade, she had moved with her husband to Florida, was undergoing fertility treatments, and had slimmed down further, to a hundred and ten pounds. On February 25, 1990, Terri suffered cardiac arrest, leading to severe brain damage. The cause was a drastically reduced level of potassium in her bloodstream, a condition frequently associated with bulimia.
Do I really even have to subject this to an analysis? Perhaps I do. All right, then. The above paragraph implies not only that a young woman who weighs two hundred and fifty pounds can be neither "attractive" nor "vivacious," but also the inverse, i.e., that losing a hundred of that two hundred and fifty pounds will automatically make you both of these things, even if you lose that weight through bulimia. Even worse, it reduces bulimia -- a disease in which people starve themselves by self-induced vomiting or abuse of laxatives -- to "diligence," and praises a dead woman for having the disease that killed her. A disease which it goes on to mention in the *very same paragraph*. Never mind that many healthy young women exist who are attractive, vivacious, *and* fat. Never mind that a young woman with bulimia, a disease which, among other things, causes feelings of ill health, is most likely anything but "vivacious." Never mind that one of the U.S.'s foremost magazines turned an opportunity to educate people about bulimia into a subtle propagation of the demonstrably false ideology that arguably killed the very person they were writing about. Never mind that the truth about what science has learned about fitness and fatness -- that there is no provable relationship between so-called obesity and poor health -- is out there for anyone who wants to read about it:
Dutch language blog about my daily life and my cats

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I like Science (aka Speculative) Fiction for its ideas  
If you want information on the authors, titles, series, dates, etc., of published works, try:
The Internet Speculative Fiction Database

ISFDB blog

ISFDB2 documentation

The Linköping Science Fiction Archive

The Locus Index to Science Fiction: Site Directory

Online Indexes:
The Locus Index to Science Fiction: 1984-1998

The Locus Index to Science Fiction: 1999

The Locus Index to Science Fiction: 2000

The Locus Index to Science Fiction: 2001

The Locus Index to Science Fiction: 2002

The Locus Index to Science Fiction: 2003

The Locus Index to Science Fiction: 2004

Index to Science Fiction Anthologies and Collections.

Science Fiction, Fantasy, & Weird Fiction Magazine Index: 1890-2001
A Checklist of Magazine Titles and Issues
This checklist is an excerpt from the Science Fiction, Fantasy, & Weird Fiction Magazine Index by Stephen T. Miller & William G. Contento, published on CD-ROM by Locus Press. The index lists by author, title, issue, and cover artist the contents of some 900 magazines with 13,000 individual issues.

The Locus Index to Science Fiction (1984-1997)

The Locus Poll Database: Locus Awards

Contento's Index to Science Fiction Anthologies and Collections

The Library of Congress Home Page

Ingram Book Group's The Book Kahoona

Mystery Short Fiction: 1990-2000

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First Person - A Mastectomy in 1811  
First Person - A Mastectomy in 1811
One reason I'd hesitate if time travel became practicable. Thank goodness for anaesthetics (& of course antisepsis).
Thursday 21/04/2005 at 10.45am, as part of Life Matters.

First Person - Letter from Fanny Burney to her sister Esther
Read by: Kate Roberts
(Listen - Real Media Format)
In 1811 Fanny Burney was diagnosed with cancer of the right breast and endured a mastectomy.

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Sometimes all that I need is the air that I breathe ...  
Sometimes all that I need is the air that I breathe ...
Department of the Environment and Heritage
GPO Box 787 Canberra ACT 2601 Australia
Telephone: +61 (0)2 6274 1111
Non-Dust Atmospheric Emissions From Minerals Processing
Environment Australia
2002 minerals/booklets/atmosphere/what-is.html

What is clean air?

The major constituents
The earth's atmosphere has evolved over geological time to its present composition, which, excluding water vapour, comprises a mixture of gases; approximately 78% nitrogen, 21% oxygen and 1% argon. The concentration of water vapour is highly variable but can reach up to 3%. This booklet is mainly concerned about gases present at concentrations much less than 1%.
The importance of trace constituents
With the exception of water vapour, the current proportions of gases are maintained by equilibrium processes which include biogenic and anthropogenic activity as well as geological processes which in many cases are intimately connected with biogenic processes. Scientists estimate that the current level of oxygen in the atmosphere was reached approximately 400 million years ago (Cloud, 1983). As the input and removal rates of the constituent gases change so too does the point at which equilibrium is established. Carbon dioxide is perhaps the most obvious example where this is occurring. Since the industrial revolution, the rate of input of carbon dioxide to the atmosphere has increased. If the input rate were to stabilise at its new higher level a new equilibrium would be established where concentrations would be higher than in the past and at the point where the removal rate matched the rate of input. The same principle applies for all the constituents of the atmosphere.
These gases are transparent to visible light. At sea-level light scattering from particle-free air would allow a theoretical visual range of approximately 320 km (Stern et al., 1984), which is well beyond the distance to horizon for most ground-based observers. Trace contamination can reduce visibility significantly. Small particles will scatter light and reduce visibility. The United States Environmental Protection Agency (US EPA, 1979) estimates that a density of 1 µg/m3 of particulate matter in the size range effective for scattering visible light (0.1 to 1 µm) along a sight line will reduce visual range by 30% from 320 km to 224 km and 10 µg/m3 will reduce visual range to between 30 and 40 km.
Not only do small changes in the composition of the atmosphere have significant effects on visibility and climate, but small changes in the concentrations of other trace gases can have implications for health and the viability of life. For example the World Health Organisation ( WHO Fact Sheet No 187 , 2000) guideline value for 15-minute exposure to carbon monoxide is 100mg/m3 (87 ppm) and the 10-minute exposure guideline for sulphur dioxide is 0.5mg/m3 (0.175 ppm). These exposure levels are acceptable, but concentrations at ten times these levels are not.
Thus clean air is best defined by quantifying the trace levels of harmful polluting gases rather than focussing on the major constituents ...
Last updated: Sunday, 20-Jun-2004 05:52:11 EST

State of the Environment Tasmania (2003)

The preparation of this SoE Report is one of the features of Tasmania's Resource Management and Planning System. SoE reporting provides a means to assess progress towards the sustainable development objectives defined under the system ...
A 'printer-friendly' version of the report, which contains the 'at a glance' pages from this website and the recommendations in full, can be downloaded from :
Atmosphere Key Concepts
Structure of the Atmosphere
Composition of Air Near the Earth's Surface
Gases Formula % by Volume
Nitrogen N2 78.08
Oxygen O2 20.95
Argon . Ar 0.93
Neon . Ne 0.001 8
Helium He 0.000 5
Hydrogen H2 0.000 05
Xenon Xe 0.000 009
Carbon dioxide CO2 variable (average 0.036)
Methane CH4 variable (average 0.000 1)
Ozone . O2 variable (polluted air average 0.000 004)
Carbon monoxide CO variable (polluted air average 0.000 02)
Sulfur dioxide SO2 variable (polluted air average 0.000 001)
Nitrogen dioxide NO2 variable (polluted air average 0.000 001)
Particles (dust etc.) variable (polluted air average 0.000 01)
Water vapour H2O variable (up to 4% in some areas)
Source: adapted from Crowder 1995 <source/523/index.php?PHPSESSID=4d6dd6e9890cd5187d5d0d971f1c37 3a&g

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Habemus Papam  
Habemus Papam
News has run through the city, and the bells are ringing in Rome. The people are gathering in Piazza San Pietro in an ancient vigil. The city and the world know there is a new Pope. They wait to see who will appear through the window and step onto the balcony.

There is a room where the newly elected one usually goes to prepare himself for the step that starts an extraordinary journey, I believe it is called The Crying Room (Chamber of Weeping). Even for someone who hoped and schemed for the position, it must not be an easy transition.

Someone must have put in a good word for Benedict XVI - at least we can put paid to the George Ringo jokes. It's Uncle Joe, sometimes called Cardinal Rat.

Well, we shall see: Man proposes; God disposes. The rain has started here in Sydney, and I am well overdue for bed.

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These recipes are not for 'Babe' lovers (Warning: Your arteries may clog up just reading). article/0,2668,ALBQ_21236_3699656,00.html
... 300 million years ago, 8-foot-long millipedes (arthropleura) were in control of the landscape in New Mexico ... "This is basically the Tyrannosaurus of the Pennsylvanian period (325-280 million years ago), millions of years before dinosaurs evolved." (Picture of a smaller specimen [ ] The largest one is only known from its footprints.) Evidence of the creatures has also been found in Nova Scotia and Scotland ... Arthropleura died out at the end of the Pennsylvanian, probably because the amount of oxygen in the air was reduced from 30 percent during that time period to closer to the 21 percent we have today, ... They just couldn't survive at that size in modern air," Lucas said. (anatomy puppets) muppet wizard of oz

The best book on vampires, ever, is Paul Barber's Vampires, Burial and Death: folklore and reality, published Yale UP 1988 [Well, that's one person's opinion. Might check this out - find a LINK] story.jsp?story=630165
Oxyrhynchus Papyri decoded
... The papyrus fragments were discovered in historic dumps outside the Graeco-Egyptian town of Oxyrhynchus ("city of the sharp-nosed fish") in central Egypt at the end of the 19th century. Running to 400,000 fragments, stored in 800 boxes at Oxford's Sackler Library, it is the biggest hoard of classical manuscripts in the world.

The previously unknown texts, read for the first time last week, include parts of a long-lost tragedy - the Epigonoi ("Progeny") by the 5th-century BC Greek playwright Sophocles; part of a lost novel by the 2nd-century Greek writer Lucian; unknown material by Euripides; mythological poetry by the 1st-century BC Greek poet Parthenios; work by the 7th-century BC poet Hesiod; and an epic poem by Archilochos, a 7th-century successor of Homer, describing events leading up to the Trojan War. Additional material from Hesiod, Euripides and Sophocles almost certainly await discovery.

Oxford academics have been working alongside infra-red specialists from Brigham Young University, Utah. Their operation is likely to increase the number of great literary works fully or partially surviving from the ancient Greek world by up to a fifth. It could easily double the surviving body of lesser work - the pulp fiction and sitcoms of the day.
Speaker A: . . . gobbling the whole, sharpening the flashing iron.

Speaker B: And the helmets are shaking their purple-dyed crests, and for the wearers of breast-plates the weavers are striking up the wise shuttle's songs, that wakes up those who are asleep.

Speaker A: And he is gluing together the chariot's rail.
These words were written by the Greek dramatist Sophocles, and are the only known fragment we have of his lost play Epigonoi (literally "The Progeny"), the story of the siege of Thebes.

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Federalism & Feminism  
Federalism & Feminism
Back in The Good Old Days (e.g. 1850s), even a married women's own earnings became her husband's. It helped trap wives in almost intolerable situations & kept suffering families under the control of sometimes bad, greedy, or incompetent men. Even after some improvements in these laws (e.g. 1950s), a wife's dependence could be used as a psychological & financial weapon.

With this government's record of withdrawing funds from people who criticise it, or just don't do exactly what they say, it's quite clear why States would prefer to keep some independent funding.

Already it has made financial threats not just to community groups and citizens who assert their responsibility to represent what they think will improve our country - or prevent harm to it - but also to State Governments with differing opinions to it.

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NewScientist: Climate change: Menace or myth?  
The bulk of this needs to be behind a 'cut', but I can't get the code to work. My apologies

NewScientist: Climate change: Menace or myth?
12 February 2005 news service
Fred Pearce

ON 16 FEBRUARY, the Kyoto protocol comes into force. Whether you see this as a triumph of international cooperation or a case of too little, too late, there is no doubt that it was only made possible by decades of dedicated work by climate scientists. Yet as these same researchers celebrate their most notable achievement, their work is being denigrated as never before.

The hostile criticism is coming from sceptics who question the reality of climate change. Critics have always been around, but in recent months their voices have become increasingly prominent and influential. One British newspaper called climate change a "global fraud" based on "left-wing, anti-American, anti-west ideology". A London-based think tank described the UK's chief scientific adviser, David King, as "an embarrassment" for believing that climate change is a bigger threat than terrorism. And the bestselling author Michael Crichton, in his much publicised new novel State of Fear, portrays global warming as an evil plot perpetrated by environmental extremists.

If the sceptics are to be believed, the evidence for global warming is full of holes and the field is riven with argument and uncertainty. The apparent scientific consensus over global warming only exists, they say, because it is enforced by a scientific establishment riding the gravy train, aided and abetted by governments keen to play the politics of fear. It's easy to dismiss such claims as politically motivated and with no basis in fact - especially as the majority of sceptics are economists, business people or politicians, not scientists (see "Meet the sceptics"). But there are nagging doubts. Could the sceptics be onto something? Are we, after all, being taken for a ride?

This is perhaps the most crucial scientific question of the 21st century. The winning side in the climate debate will shape economic, political and technological developments for years, even centuries, to come. With so much at stake, it is crucial that the right side wins. But which side is right? What is the evidence that human activity is warming the world, and how reliable is it?

First, the basic physics. It is beyond doubt that certain gases in the atmosphere, most importantly water vapour and carbon dioxide, trap infrared radiation emitted by the Earth's surface and so have a greenhouse effect. This in itself is no bad thing. Indeed, without them the planet would freeze. There is also no doubt that human activity is pumping CO2 into the atmosphere, and that this has caused a sustained year-on-year rise in CO2 concentrations. For almost 60 years, measurements at the Mauna Loa observatory in Hawaii have charted this rise, and it is largely uncontested that today's concentrations are about 35 per cent above pre-industrial levels (see Graph).

The effect this has on the planet is also measurable. In 2000, researchers based at Imperial College London examined satellite data covering almost three decades to plot changes in the amount of infrared radiation escaping from the atmosphere into space - an indirect measure of how much heat is being trapped. In the part of the infrared spectrum trapped by CO2 - wavelengths between 13 and 19 micrometres - they found that between 1970 and 1997 less and less radiation was escaping. They concluded that the increasing quantity of atmospheric CO2 was trapping energy that used to escape, and storing it in the atmosphere as heat. The results for the other greenhouse gases were similar.

These uncontested facts are enough to establish that "anthropogenic" greenhouse gas emissions are tending to make the atmosphere warmer. What's more, there is little doubt that the climate is changing right now. Temperature records from around the world going back 150 years suggest that 19 of the 20 warmest years - measured in terms of average global temperature, which takes account of all available thermometer data - have occurred since 1980, and that four of these occurred in the past seven years (see Graph).

The only serious question mark over this record is the possibility that measurements have been biased by the growth of cities near the sites where temperatures are measured, as cities retain more heat than rural areas. But some new research suggests there is no such bias. David Parker of the UK's Met Office divided the historical temperature data into two sets: one taken in calm weather and the other in windy weather. He reasoned that any effect due to nearby cities would be more pronounced in calm conditions, when the wind could not disperse the heat. There was no difference.

It is at this point, however, that uncertainty starts to creep in. Take the grand claim made by some climate researchers that the 1990s were the warmest decade in the warmest century of the past millennium. This claim is embodied in the famous "hockey stick" curve, produced by Michael Mann of the University of Virginia in 1998, based on "proxy" records of past temperature, such as air bubbles in ice cores and growth rings in tree and coral. (see "Hotly contested") Sceptics have attacked the findings over poor methodology used, and their criticism has been confirmed by climate modellers, who have recently recognised that such proxy studies systematically underestimate past variability. As one Met Office scientist put it: "We cannot make claims as to the 1990s being the warmest decade."

There is also room for uncertainty in inferences drawn from the rise in temperature over the past 150 years. The warming itself is real enough, but that doesn't necessarily mean that human activity is to blame. Sceptics say that the warming could be natural, and again they have a point. It is now recognised that up to 40 per cent of the climatic variation since 1890 is probably due to two natural phenomena. The first is solar cycles, which influence the amount of radiation reaching the Earth, and some scientist have argued that increased solar activity can account for most of the warming of the past 150 years. The second is the changing frequency of volcanic eruptions, which produce airborne particles that can shade and hence cool the planet for a year or more. This does not mean, however, that the sceptics can claim victory, as no known natural effects can explain the 0.5 °C warming seen in the past 30 years. In fact, natural changes alone would have caused a marginal global cooling (see Graph).
How hot will it get?

In the face of such evidence, the vast majority of scientists, even sceptical ones, now agree that our activities are making the planet warmer, and that we can expect more warming as we release more CO2 into the atmosphere. This leaves two critical questions. How much warming can we expect? And how much should we care about it? Here the uncertainties begin in earnest.

The concentration of CO2 in the atmosphere now stands at around 375 parts per million. A doubling of CO2 from pre-industrial levels of 280 parts per million, which could happen as early as 2050, will add only about 1 °C to average global temperatures, other things being equal. But if there's one thing we can count on, it is that other things will not be equal; some important things will change.

All experts agree that the planet is likely to respond in a variety of ways, some of which will dampen down the warming (negative feedback) while others will amplify it (positive feedback). Assessing the impacts of these feedbacks has been a central task of the UN's Intergovernmental Panel on Climate Change, a co-operative agency set up 17 years ago that has harnessed the work of thousands of scientists. Having spent countless hours of supercomputer time creating and refining models to simulate the planet's climate system, the IPCC concludes that the feedbacks will be overwhelmingly positive. The only question, it says, is just how big this positive feedback will be.

The latest IPCC assessment is that doubling CO2 levels will warm the world by anything from 1.4 to 5.8 °C. In other words, this predicts a rise in global temperature from pre-industrial levels of around 14.8 °C to between 16.2 and 20.6 °C. Even at the low end, this is probably the biggest fluctuation in temperature that has occurred in the history of human civilisation. But uncertainties within the IPCC models remain, and the sceptics charge that they are so great that this conclusion is not worth the paper it is written on. So what are the positive feedbacks and how much uncertainty surrounds them?

Melting of polar ice is almost certainly one. Where the ice melts, the new, darker surface absorbs more heat from the sun, and so warms the planet. This is already happening. The second major source of positive feedback is water vapour. As this is responsible for a bigger slice of today's greenhouse effect than any other gas, including CO2, any change in the amount of moisture in the atmosphere is critical. A warmer world will evaporate more water from the oceans, giving an extra push to warming. But there is a complication. Some of the water vapour will turn to cloud, and the net effect of cloudier skies on heat coming in and going out is far from clear. Clouds reflect energy from the sun back into space, but they also trap heat radiated from the surface, especially at night. Whether warming or cooling predominates depends on the type and height of clouds. The IPCC calculates that the combined effect of extra water vapour and clouds will increase warming, but accepts that clouds are the biggest source of uncertainty in the models.

Sceptics who pounce on such uncertainties should remember, however, that they cut both ways. Indeed, new research based on thousands of different climate simulation models run using the spare computing capacity of idling PCs, suggest that doubling CO2 levels could increase temperatures by as much as 11 °C (Nature, vol 434, p 403).

Recent analysis suggests that clouds could have a more powerful warming effect than once thought - possibly much more powerful (New Scientist, 24 July 2004, p 44). And there could be other surprise positive feedbacks that do not yet feature in the climate models. For instance, a release of some of the huge quantities of methane, a potent greenhouse gas, that are frozen into the Siberian permafrost and the ocean floor could have a catastrophic warming effect. And an end to ice formation in the Arctic could upset ocean currents and even shut down the Gulf Stream - the starting point for the blockbuster movie The Day After Tomorrow.

There are counterbalancing negative feedbacks, some of which are already in the models. These include the ability of the oceans to absorb heat from the atmosphere, and of some pollutants - such as the sulphate particles that make acid rain - to shade the planet. But both are double-edged. The models predict that the ocean's ability to absorb heat will decline as the surface warms, as mixing between less dense, warm surface waters and the denser cold depths becomes more difficult. Meanwhile, sulphate and other aerosols could already be masking far stronger underlying warming effects than are apparent from measured temperatures. Aerosols last only a few weeks in the atmosphere, while greenhouse gases last for decades. So efforts to cut pollution by using technologies such as scrubbers to remove sulphur dioxide from power station stacks could trigger a surge in temperatures.

Sceptics also like to point out that most models do not yet include negative feedback from vegetation, which is already growing faster in a warmer world, and soaking up more CO2. But here they may be onto a loser, as the few climate models so far to include plants show that continued climate change is likely to damage their ability to absorb CO2, potentially turning a negative feedback into a positive one.
Achilles' heel?

More credible is the suggestion that some other important negative feedbacks have been left out. One prominent sceptic, meteorologist Richard Lindzen of the Massachusetts Institute of Technology, has made an interesting case that warming may dry out the upper levels of the innermost atmospheric layer, the troposphere, and less water means a weaker greenhouse effect. Lindzen, who is one of the few sceptics with a research track record that most climate scientists respect, says this drying effect could negate all the positive feedbacks and bring the warming effect of a doubling of CO2 levels back to 1 °C. While there is little data to back up his idea, some studies suggest that these outer reaches are not as warm as IPCC models predict (see "Areas of contention). This could be a mere wrinkle in the models or something more important. But if catastrophists have an Achilles' heel, this could be it.

Where does this leave us? Actually, with a surprising degree of consensus about the basic science of global warming - at least among scientists. As science historian Naomi Oreskes of the University of California, San Diego, wrote in Science late last year (vol 306, p 1686): "Politicians, economists, journalists and others may have the impression of confusion, disagreement or discord among climate scientists, but that impression is incorrect."

Her review of all 928 peer-reviewed papers on climate change published between 1993 and 2003 showed the consensus to be real and near universal. Even sceptical scientists now accept that we can expect some warming. They differ from the rest only in that they believe most climate models overestimate the positive feedback and underestimate the negative, and they predict that warming will be at the bottom end of the IPCC's scale

For the true hard-liners, of course, the scientific consensus must, by definition, be wrong. As far as they are concerned the thousands of scientists behind the IPCC models have either been seduced by their own doom-laden narrative or are engaged in a gigantic conspiracy. They say we are faced with what the philosopher of science Thomas Kuhn called a "paradigm problem".

"Most scientists spend their lives working to shore up the reigning world view - the dominant paradigm - and those who disagree are always much fewer in number," says climatologist Patrick Michaels of the University of Virginia in Charlottesville, a leading proponent of this view. The drive to conformity is accentuated by peer review, which ensures that only papers in support of the paradigm appear in the literature, Michaels says, and by public funding that gives money to research into the prevailing "paradigm of doom". Rebels who challenge prevailing orthodoxies are often proved right, he adds.

But even if you accept this sceptical view of how science is done, it doesn't mean the orthodoxy is always wrong. We know for sure that human activity is influencing the global environment, even if we don't know by how much. We might still get away with it: the sceptics could be right, and the majority of the world's climate scientists wrong. It would be a lucky break. But how lucky do you feel?

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