Wednesday, May 21, 2014

What Should Replace Religion?

What Should Replace Religion (Originally Posted October, 2010)
Daniel Dennett earlier this afternoon delivered at the Atheist Alliance Conference in Montreal a talk entitled, "What Should Replace Religion?".   It's a rather presumptuous question, which Dennett admitted at the outset.  I've never seen him speak in person, but his roughly one hour presentation was in line with those I've viewed on youtube:  clear, concise, entertaining, and thought provoking.  Unlike his other presentations, however, his thesis was wrong.  Clearly wrong.

The premise of Dennett's thesis was not really "What should replace religion?", but what positive elements or products of religion should we consider retaining?  He provided a laundry list of possibilities that included hope, love, music, art, and community.  There were quite a few more items in the list, but I can't remember them all and it's actually irrelevant.  It's irrelevant, because everything on his list is not the sole domain of religion any more than morals are owned by religion.   Would music disappear in the abscence of religion?  Love?  Hope?  Community?  No.  Isn't this obvious?

To be sure, religion has had influence on many things.  Music can be inspired by religion or religious experience.  Dennett gave the example of the Bach cantatas that are performed at a local church just outside Boston.  Bach was a musical genius--one of the greatest composers in the history of the modern world.  Would he have failed to compose music without religion?  I think not.  While I'm orders of magnitude below the capabilities and talent of Bach, I compose, arrange, and perform music without any religion at all.  I suspect that Bach's inate music ability would have found an outlet in a secular society if such a thing existed in early 17th century.  And I would suggest his musical output would be no less spectacular.  Turning to modern times, Dennett provided a further musical example: gospel music.  Clearly the lyrics of gospel music are religious and the performance of gospel has roots in the church.  But, would have gospel music failed to emerge under a secular history?  Maybe.  Maybe not.  I am certain that some sort of music, perhaps a new genre that we will now never know precisely because of religion, would have emerged from the experience and struggles of blacks in the south.  Maybe we'd have secular gospel music, not unlike the new gospel music that got Dan waving his arms in the air, as well as a few others in the crowd.   Music is not owned by religion.   Therefore, there is no need to consider whether it is a quality that we should consider retaining from religion.

Daniel Dennett gets "religious" listening to atheist gospel music:  
gospel-style music with secular and atheist lyrics.

The same argument applies to love, hope and everything else on the list.  Can atheists love?  Sure.  So, why is that a quality that should be retained from religion.  It's not a religious quality at all.   I'm rather shocked--disappointed, actually--that Dennett would make such an obvious error in reasoning.  There is nothing of value that religion provides uniquely.  Nothing.  It provides no knowledge or insight into the understanding of the universe, and it has no claim to morals, emotions, music, art or any of the other valuable qualities of the human experience.  I would suggest that rather than promoting the items on Dennett's list, religion often suppress and destroys many of the positive aspects of life that we cherish.   Hope and religion:  hope that you don't burn in hell?  Love:  unless of course your gay.  Community?  Sure, as long as you have the correct religion otherwise you burn in hell.

I'm sure a youtube recording of the presentation will be made available soon.  I'll post an update with a link if and when that happens so that you can listen and decide for yourselves.
Posted by Scot Rafkin at 8:59 PM (Originally posted October, 2010)

Wednesday, April 10, 2013

The Cognitive Dissonance of Sam Harris

In “The Moral Landscape”, Sam Harris argues that morality can be determined by considering the impact of actions on social well being.  The impact is quantifiable through the relative comparison of possible social states arising from different actions.  A moral action is one that produces the greatest relative maximum in the topology of possible states of societal well being.  Let us take this definition of morality as an axiom.  For the purposes of this piece, it matters only that Sam Harris believes it to be true not that it is true. 

Now also consider Sam Harris’ position on guns.  He argues vociferously for the right to own guns.  Lots of them.  Of many kinds.  For example, in his “The Riddle of the Gun” he writes:

“Wouldn’t any decent person wish for a world without guns? In my view, only someone who doesn’t understand violence could wish for such a world. A world without guns is one in which the most aggressive men can do more or less anything they want. It is a world in which a man with a knife can rape and murder a woman in the presence of a dozen witnesses, and none will find the courage to intervene.

This is, of course, a strawman argument.  Few are calling for a world without guns, although it is reasonable to ask whether such a world would be in a state of greater well being than a world where guns are ubiquitous.  Does it really follow that in a world without guns that a man with a knife can rape and murder?  Are law abiding citizens really helpless in a world without guns?  Do we see women being raped and murdered across Western Europe where guns are generally far less common than in the U.S.?  Is crime rampant in the UK where not even the police carry firearms (except for Ireland)?  And, couldn't non-lethal methods be used?  How about tasers or pepper spray?  Are guns the only defense we have against violence?  It's a strawman and a false dichotomy.

The reality is, reasonable people are calling for greatly limiting access to firearms or removing certain types of firearms from society.  Is the resulting scenario a state where well being would be increased?  Suppose only law enforcement carried firearms so as to protect law abiding citizenry from violence.  Would this result in a state of higher well being than we have now?  Conversely, would well being be increased by increasing the number of guns and allowing nearly everyone to carry multiple firearms at all times? 

Measuring well being is subjective, so reasonable people might disagree over whether one possible outcome is better than another.  However, it seems that in the spectrum of possible states of well being, a society in which there were no guns, or at the very least, a society where only law enforcement carried firearms would be better off than a society where guns flow like water.  And a society with non-lethal weaponry might be yet an even higher state of well being.

Sam Harris’ moral landscape position seems incompatible with his stance on gun control.  He has provided all sorts of arguments to support his position on guns, but interestingly, he has not yet, as far as I know, argued his position in terms of the moral landscape.  If morality can indeed be quantified by testing actions against their effect on well being, then Harris’ best argument for guns would be to show that a society armed to the teeth is better off than a society without firearms.  Good luck with that one, Sam.  I suspect that in the end, you'll have to choose either guns, or the philosophy of the moral landscape, or reject both.  But you can't have both guns and the philosophy of the moral landscape.

Thursday, August 9, 2012

What Causes Hurricanes (and Some Mars Dust Storms)?

It's not uncommon that I hear incorrect explanations for the origin or behavior of various atmospheric phenomena.  This post was inspired by a recent event where an individual insisted that "extreme pressure variations" are needed to produce a hurricane.  Below, I describe the actual mechanisms that produce a hurricane.  It turns out the same physics may also be responsible for producing some Mars dust storms.

Consider first a motionless atmosphere with no horizontal pressure variations at all.  That is to say, there is no wind and if you were to look at a weather map you would see no high or low pressures.  It is from this state that hurricanes (also known as tropical cyclones) develop.  Immediately, you can see that if this is indeed the initial scenario, then the assertion that "extreme pressure variations" are necessary is exactly wrong.

In reality, there is no such idealized state in the atmosphere.  There is always some amount of pressure variation and therefore some amount of wind.  The process I will describe below works just as well as long as these winds and pressure variations are small.

From this rather boring initial state, heat a chunk of air near the surface from the sun.  It becomes buoyant like a hot air balloon, and rises.  In the tropics, it is not unusual that such rising motion will develop into individual thunderstorms.  Inside a thunderstorm, water vapor condenses, which releases heat.  This heating causes the air to expand.  (Slightly technical here: this is an adiabatic expansion, meaning that no net energy is being added; even though there is heating due to condensation, it is internal heating and represents no external energy input).  This expansion has the effect of causing a weak low pressure to develop near the surface and weak high pressure to develop aloft.  Once there is a low pressure at the surface, horizontal winds develop and begin to flow toward the storm.

If the thunderstorm is over water, the wind now flowing toward the storm interacts with the underlying ocean.  The interaction is actually quite complex, but I'll distill the essential and relevant parts here.  If the ocean is warmer than the air, the air will be heated through turbulent eddies transporting the heat of the ocean upward.  The strength of the turbulent eddies and therefore the efficiency of the exchange is related to the wind speed and the difference in temperature between the atmosphere and the ocean surface.  If the wind is strong (all other things being equal) the exchange will be strong.  If the temperature difference is strong (all other things being equal) the exchange will be strong.

In the case we have so far, the winds are rather weak, so the exchange is rather weak.  Nonetheless, energy is being added to the atmosphere and carried toward our thunderstorm. (Actually, it is entropy that is being transported, but it's not important at this level of discussion, and I digress...)  As the air flows toward the weak low pressure, it expands.  Normally, this expansion would cause cooling.  However, the warm ocean underneath keeps the temperature of the air nearly constant as it expands.  In other words, the heat the air receives from the ocean nearly balances the cooling due to expansion.  This is called an isothermal (same temperature) expansion process.

Once at the storm, the air rises, condenses, and heats the atmosphere.  This strengthens the low pressure at the surface.  In turn, this increases the wind speed flowing toward the storm.  And this in turn increases the heat exchange between the atmosphere and the ocean (recall that the magnitude of the exchange is related to the wind speed).

It should be clear that what we have is a feedback process.   It's a process that reinforces itself.  As more energy is picked up by the air flowing towards the storm, the more heating is produced in the storm, the lower the pressure drops, and the stronger the winds get.  If you look at the entire system of air flowing toward the storm, air rising in the storm, air flowing out of the storm aloft, and then sinking away from the storm, you have a complete cycle.  Approximately 30 years ago the thermodynamics of this system was recognized in two landmark papers (you can get them here and here).  It turns out to be a sort of Carnot engine.  The process was called "Wind-Induced Sensible Heat Exchange", because it coupled the wind to the exchange of heat energy with the ocean.  While the fine details of this mechanism are still being debated in the literature, the overall process is now well established.   In essence, the engine extracts heat from a source, in this case the ocean and turns it into mechanical work (in this case increasing wind speed).

For simplicity sake, I've left out a lot of details, but these are not relevant to the big picture here.  There is at least one detail that is relevant:  The Earth rotates.  This means that as the air moves, it will experience an apparent deflection.  If the movement is over a sufficiently long time, this will result in the air beginning to rotate around the low pressure rather than flowing toward it.  If nothing else were to happen, there would be no air flowing to the storm, just going around it.  That would be the end of the storm.  But, there is friction.  Friction keeps some component of the motion always flowing toward the low pressure.  Thus, the feedback process may continue.  Furthermore, because friction is also a function of wind speed, the strong the winds, the stronger the friction, which dictates how much energy can flow to the storm.

The above process is the basic concept of how hurricanes develop.   No "extreme pressure variations" are needed.  The storm can develop from a completely motionless  atmosphere with no pressure variation at all.  It actually depends on the lack of an initial pressure variation.

Why don't all storms develop into hurricanes?  There's lots of things that can mess up the feedback process.  One is that the system moves over land.  Then there is no heat exchange with the ocean.  Another is that the initial storm can be too close to the equator.  The deflection of winds at the equator is zero, so no rotation can develop.  If the storm moves to higher latitudes, the ocean can become too cold and this limits the energy that can be provided.  Another major hindrance to storm formation is the presence of strong wind shear.  Wind shear is a change of wind speed or direction with height.

Here's the thing about wind shear:  Wind shear results when there are strong pressure variations.  For example, the jet stream is a result of strong large scale pressure differences.  Hurricanes and jet streams just don't get along.  The strong winds that result from the strong pressure differences literally rips the hurricane apart by shearing the top of it off.

Not only do hurricanes not form because of extreme pressure variations, they are prohibited by extreme pressure variations, because such variations produce wind shear.

Obviously, once a hurricane forms, it has strong pressure variations related to the storm itself.  This is not what causes the storm however.  The strong pressure variations are a result of the storm, not the other way around.  The hurricane is produced by the Wind-induced Sensible Heat Exchange--a process that transfers heat from the ocean to the atmosphere.  The process depends upon having a relatively flat pressure field for it to start and proceed.  Again, if extreme pressure variations are present the associated wind shear will disrupt the entire process.

I mentioned early on that a similar process may  occur in some Mars dust storms.  I published a paper about this a couple of years ago (here).  Dust essentially provides the heating on Mars.  As air flows toward the storm, dust is lifted, and that dust is radiatively heated by the sun.  Winds increase in the disturbance and this causes more dust to be lifted.  Thus, I named the process Wind-Enhanced Interaction of Radiation and Dust (WEIRD)  in recognition of the WISHE analog to hurricanes.

Wednesday, September 1, 2010

A Short Lesson in Thermodynamics as it Relates to Life

I was recently presented with the statement that “life is the only force that counters entropy”. This can be taken to mean one of two things. The first is that life results in a net decrease in entropy.  The second is that while life may result in a net increase in entropy, entropy of the life form itself is reduced and life is the only such system that can do this. The first argument is nonsense, as it violates the 2nd Law of Thermodynamics.  The second statement is just plain false; there’s nothing thermodynamically unique about life. Let’s look at both situations to understand why.

The first order of business is to define entropy. There are lots of valid definitions and all valid definitions can be shown to be equivalent. One definition of entropy is the amount of energy that cannot be used to do work. Doing work requires energy. For example, if you want to move something, you need to expend energy.  Except for theoretical systems, whenever energy is expended by a system, some of the energy is wasted—not all the energy can be used to do work. For example, when you move an object, you expend energy to flex your muscles, and this is translated into kinetic energy (energy of motion). As your muscles flex, heat is created. This heat is sent into the environment and is not used to move the object. Thus, entropy is increased in an amount related to the wasted energy.

The inefficiency of systems that do work is at the crux of the 2nd Law of Thermodynamics. In a theoretically perfect system, all the energy would go to do work and no heat would be generated. a perfect system can at best use all energy to do work (resulting in no net decrease in entropy). An imperfect system (e.g., a real world system) will have an inefficiency so that some energy is wasted. The wasted energy produces a net increase in entropy. No system can do work to produce more energy than is needed to do the work. This would be a perpetual motion machine and it would generate a net decrease in entropy.

We can now investigate whether life counters entropy. The answer is no, at least not in the global, net sense. Life can do work (e.g., grow, reproduce, move, etc.), but all these processes involve an inefficient expenditure of energy. Life increases entropy. Period.

Now let’s look at the second possible meaning of “life is the only force that counters entropy.” To do this, let’s consider a different, but equivalent measure of entropy. Entropy is also a measure of organization (or disorganization). A system that moves toward more order has a decrease in entropy. The existence of such a system may seem impossible given the discussion above, but it is not. A system can have a decrease in entropy at the expense of its surroundings. The surroundings will suffer a larger increase in entropy than the decrease in the system, resulting in an overall increase in total entropy. There are a multitude of examples of systems in which entropy is decreased.

Life is indeed one such example. Cells and organisms are assembled from a more disorderly system of atoms and molecules. Life takes in nutrients and assembles these into orderly functioning life systems. So, in this sense, one could say that life counters entropy. This of course ignores that life, on the whole, actually increases entropy when life plus its environment is considered. The outstanding question is whether life is the ONLY system to do so. The answer is clearly and resoundingly, “no”.

Well known examples of systems that have a reduction in entropy are air conditioners and refrigerators, crystal formation, and planet formation. The true list of such systems is possibly infinite. Air conditioners produce cold air from hot air. The cold air is slightly more ordered than the hot air. Entropy decreases. But this is only true if the waste heat is neglected. Anyone that has spent even a small amount of time around an air conditioner knows that in order to produce cold air, hot air—much hotter than originally ingested—must be
ejected. So, in net, entropy increases. Entropy is lower in the cold air, but it is higher in the hot air, and the net effect is an overall increase in entropy. Crystals are very orderly. This order represents a reduction of entropy compared to the original unorganized, uncrystalized molecules. But, as in the previous example, the environment suffers a larger increase in entropy in order to allow for crystallization. Cyrstalization generates waste heat and, therefore, an increase in entropy. The net change in entropy is positive. Solar Systems form from a collection of gases and dust. These spiral in and accrete into larger bodies, eventually becoming planets—a more orderly arrangement. But, this process generates heat, and the entropy generated from solar system formation exceeds the reduction in entropy associated with greater organization.

So, there you have it. The first interpretation is wrong and the second interpretation is wrong. Life does not counter entropy, at least in the global sense. Life increases entropy. The second interpretation is wrong even if life is viewed in isolation from its surroundings. In such a situation, life produces a reduction in entropy in the isolated life system, but there is nothing unique about this process. Lots of systems, in absence of their environment, constitute a reduction in entropy. Life is not the “only” system to do so.

Making a statement such as “life is the only force to counter entropy” is at best misleading, because it implies that life has the overall effect of decreasing entropy. It can’t do this, because of the 2nd Law of Thermodynamics. If the proponent of such a statement tries to hide behind the canard of only talking about the system in isolation, they will find themselves once again in the wrong corner, because life is not in any way unique in this regard. In short, there’s nothing thermodynamically special or unique about life.

Sunday, January 3, 2010

The Death of Planets

The Death of Planets.  No, not the planets themselves.  The idea or concept of what we have recently called planets is doomed, with the demotion of Pluto to a dwarf planet being the most recent step in a process that began with Copernicus.  Then end game will be the realization that the concept of a planet as a meaningful astronomical class of objects is antiquated and archaic.  The concept of planet is no longer compatible with what we know about the Universe.  The bickering by a minority of astronomers about the definition of a planet, and which has achieved tremendous exposure in the public arena, is as pointless as the flat Earthers arguing about whether the flat Earth is rectangular or circular. 

Since humans first looked up at the night sky, they noted that there were some objects, often brighter than the rest that did not follow the other objects in their regular movement across the sky.  The ancient Greeks labeled these objects as “The Wanderers”, or as we know them, planets.  Thousands of years ago, the segregation of these special objects from the rest of the celestial chaff made sense; they were clearly different than all the lights in the night sky, and there was no mistaking what was a planet and what was a star.

       The path of Mars against the fixed stars as viewed from Earth. Click on Image to see animated version.  (Image Source: Unknown) 

Then came Nicolaus Copernicus (19 February 1473 – 24 May 1543) and Galilei Galileo (15 February 1564 – 8 January 1642).  In less than a century, the crystalline spheres upon which the stars rode and the Ptolemic epicycles that described the motion of the planets, came crashing down.  The wanderers were in orbit about the Sun, not the Earth, and they were not just points of light, but other worlds.  Some like Jupiter, had moons, just like Earth.  Luna, the Earth’s moon, had mountains and craters.  And there was more, much more.  The skies were crowded with stars that could not be seen with the naked eye, but which revealed themselves through magnification (this includes nebula and galaxies which could not be easily distinguished from individual stars back then).  The origin of the “milkiness” of  the Milky Way became obvious—it was composed of stars, packed so closely together in such great density that they appeared as a hazy cloud. 

Until 1781, the number of known planets remained at six, all of which could be observed by the naked eye without the aid of a telescope (Mercury, Venus, Earth, Mars, Jupiter, and Saturn).  Sir William Herschel discovered Uranus in 1781.  Neptune was discovered by a Ph.D. student, Johann Galle in 1846, based on predictions provided by Urbain Le Verrier, which explained the small orbital perturbations of Uranus.  The search for a ninth planet (at the time needed to explain additional perturbations in the orbits of Neptune and Uranus, but no longer needed now that the masses of the previous eight planets are better constrained) was ended in 1930 with the discovery of Pluto by Claude Tombaugh.  Pluto was a bit of an odd planet.  It was very small, but more importantly, it orbited in a plane about the Sun that was significantly different than all the other planets.  Neither Uranus, Neptune nor Pluto can be seen without a telescope.

The orbits of the classical planets about the Sun.  All but pluto orbit in nearly the same ecliptic plane. (Image Source: Unknown)

Oddly enough, what we now call an asteroid named Ceres, was discovered in 1801 by Giuseppi Piazzi.  Like the other known planets at the time, it was a wanderer, in orbit about the Sun between Mars and Jupiter.  By all accounts Ceres was a planet, and although not known at the time, it was spheroidal like a planet.    Indeed, it was considered a planet at the time of its discovery.  Within a year or two, the inner Solar System began to get a lot more crowded.  Pallas, Juno, and Vesta were discovered, also in orbit about the Sun between Mars and Jupiter.  It was not long before dozens and dozens of these objects were found.  By the turn of the century, there were hundreds.

The known objects in the inner Solar System, including asteroids (white) and trojans (green).  Hundreds of additional objects are discovered every year.  (Image credit: Unknown; data source: Minor Planet Data Center).

For no other reason than their location between Mars and Jupiter, these objects which had all the same orbital properties of the classical planets, were put into a new class of objects, called asteroids, as suggested by Sir Herschel (the discoverer of Uranus).  However, for many years, the terms planets and asteroids were used interchangeably in the scientific literature.  By the time thousands of the objects had been discovered, the need to distinguish within the literature the classical planets from these minor planets led to the acceptance of the term asteroid (as well as minor planet), which has remained to this day.  Importantly, at the time, the distinction between asteroids and planets was merely one of convenience. 

Asteroid and former planet Ceres, as viewed through the Hubble Space Telescope by my friend and colleague J. Parker at Southwest Research Institute.  Ceres is massive enough that its shape is spheroidal.  (Image credit:  NASA)

For more than a hundred years after the discovery of the first asteroid, Ceres, the known objects in the Solar System consisted of the Sun, the classical planets and their moons, the asteroids, and the occasional comet.  Then, suddenly, the population of the Solar System once again exploded.

Dave Jewitt and his former graduate student Jan Luu found the first Kuiper Belt Object (KBO) in 1992.  KBOs are found outward from the orbit of Neptune to ~55 AU.  Pluto is within this region and is one of the  largest KBOs.  Thousands of these objects are now known to exist, including Eris, which is thought to be slightly larger than Pluto, and Quaoar, Makemake, Haumea, and Ixion, all of which are at least half as large as Pluto.  Pluto is not alone in the outer Solar System, nor is it unique. 

 Known Outer Solar System Objects consist mainly of KBOs. (Image source: Unknown; Data obtained from Minor Planet Center).

Beyond the Kuiper Belt there has been theorized to exist the Oort cloud, filled with additional icy debris left over from the early formation of the solar system.  It is from the Oort cloud that comets may originate.

We now know (thanks to increasingly powerful telescopes and spacecraft exploration) that objects in the Solar System come in a remarkable variety of shapes, sizes and compositions.  The classical planets are all spheroidal.  The inner planets and asteroids are rocky.  The outer planets are gaseous or liquid metal.  The KBOs are icy (probably mostly methane and water ice).   The largest of the asteroids and KBOs are also spheroidal; this an inescable consequence of physics—at some point an object becomes large enough that its self gravity causes it to collapse upon itself and reaches so-called hydrostatic equilibrium.   At the very small end of the size distribution, we know there exist small grains of dust.  Thus, the Solar System is populated by objects smaller than a dust grain and as large as the Sun with a continuum of objects in between.

Asteroids can occasionally present a hazard to the Earth (just ask the dinosaurs).  Recent efforts to survey the asteroid belt for those objects that may pose a future hazard has resulted in a very well characterized size distribution.  As the size of asteroids decreases, the number of asteroids increases.  In other words, there are just a few very large asteroids (Ceres, Vesta), and thousands upon thousands of the very small (under 100 m).  

The size distribution of asteroids surveyed by the Sloan Telescope.  The population number is normalized the population of 10 km objects.  The asteroid population is a continuum, as is the population of objects in the Solar System.  (Image credit:  Unknown).

If the origin of the classical planets and their moons, the asteroids, the KBOs, and the uncountable dust grains were different, these different origins might serve as a means by which to establish a scientific categorization.   However, the origin of all these objects is the same.  All the objects are the result of countless collisions and gravitational collapse of a protoplanetary disk.   It is the collision and accretion that results in the nearly log-normal size continuum of objects in the Solar System.  Asteroids are just the bits of rubble left over that were not accreted by larger objects.   The asteroids themselves may very well be conglomerations of smaller bits of dust and rock rather than the more solid monolithic structures of the science fiction genera.  KBOs are the bits of rubble in the Outer Solar System that were not accreted.

So here we are today.  We inherited the term planet, originally used to describe the wandering nature of objects against the more predictable background stars.  Millennia ago, we were aware of only a handful of these objects.  In time we found that the wanderers were not only distinct from stars in their journey across the sky, but that they were not stars at all; they really were in a class by themselves.  The idea of planet made sense.  Then, we found that there were more than just a handful of planets.  First there were dozens, then hundreds, then thousands, then tens of thousands!  It still makes sense to distinguish these objects from stars, as they are quite clearly different (for example, there is no nuclear fusion and they are not at the center of the Solar System). 

What does not make scientific sense is to further scientifically categorize the range of solar system objects.  Doing so inherently requires defining arbitrary defining lines in a size continuum.  While such dividing lines can certainly be legislated by such bodies as the International Astronomical Union (IAU), they have no meaningful basis, and such an exercise merely brings to light the hubris of man trying to sort nature into boxes and bins.

In time, the concept of a planet will find its way to the dust bins of astronomical rubbish, atop celestial spheres and the geocentric model of the Solar System.  Astronomers of the future will recognize the continuum of objects in our Solar System and in extra solar systems, too.  Any distinction between objects will be one of convenience rather than of scientific purpose, just as asteroids were once distinguished from planets solely for convenience.  Historians of science will study the transition of the Classical Planetary Model to the Modern Solar System Continuum Model, and children of the future will chuckle at the silly argument made over whether Pluto is a planet, just as we all chuckle over the argument of a circular or rectangular flat Earth.

The concept of a planet is dead. 

Wednesday, December 16, 2009

Overwhelming Scientific Consensus on Anthropogenic Global Warming? Beyond a Doubt.

I just returned to my hotel after attending my first day at this year's American Geophysical Union Fall Conference in San Francisco.  The meeting started on Monday and runs through the entire week.  It is the largest meeting by far for the Earth and Planetary Sciences with well over 12,000 scientists in attendance.

After listening in on this morning's session on Venus, and prior to the Venus poster session, I found myself with a couple of hours of unscheduled time.  It didn't make sense to walk back to the hotel, as I would have to turn around an hour later and walk back the Moscone Conference Center.  Instead, motivated by some recent discussions on internet fora, I decided to attend a few talks and browse a few poster presentations related to global and regional climate change.
It was a bit like coming home.  My education is firmly grounded in the Earth and Atmospheric Sciences.  All my graduate research was related to the Earth's atmosphere.  It's only in the last decade that I transitioned to planetary work.  Not surprisingly, I ran into a few old friends and grad school buddies that remained in the terrestrial scientific community.  I was able to catch up on a few topics that I hadn't thought about for quite some time.  I even took note of a few terrestrial studies that might have some application to the work I'm currently doing on Mars and Titan.

A picture paints a thousand words, but unfortunately the camera in phone decided to go kaput, so let me describe what I saw at the poster sessions, hopefully in less than a thousand words.  Imagine a room the size of a football stadium.  Now double it.  This is roughly the size of the room allocated to display posters.  Within this room are dozens of aisles of bulletin boards, numbered from one to approximately 2,000.  Each day, the posters change, resulting in the display of roughly 10,000 scientific presentations over the conference period.  [Edit:  Turns out there are gaps in the numbering, so that actual number of posters is actually close to several thousand.]  The aisles of posters are categorized into broad topics like "Planetary Science", "Atmospheric Science", "Seismology", etc.  Within these broad categories there is further categorization into subfields such as "Climate Change", "Climate Observations", "Regional Modeling", "Stratospheric Dynamics", etc.  In order to avoid mass congestion, poster presentations are scheduled on a staggered system; only about one-half of the room has active presentations at any given time, although all the posters are up for perusal.  The scientific content in the room is massive.

A good fraction of the posters are related to climate and climate change.  Some directly target the issue of anthropogenic global warming (AGW), some are tangentially related to AGW and investigate, for example, global and regional climate model accuracies. Other posters look at various observational records, while still others focus on the intersection of science and policy.  Just about every angle on the AGW issue is covered in some manner.

Clearly, given what I've just described, it was not possible to read every poster in detail.  Likewise, there are so many lectures on climate science, that they are often scheduled on top of one another; it's not possible to attend every talk.  Still, most posters have a summary section or conclusion section that can be read in just a couple of minutes.  Based on the talks I did attend, on reading some posters in detail, on reading most of the poster conclusions, and on talking with a variety of the presenters, there is only one possible conclusion that can be reached regarding the consensus of experts on AGW:

There is overwhelming scientific consensus on the issue of Anthropogenic Global Warming.  That consensus is that humans are producing a warming of the climate due to the emission of CO2 and the positive climate feedbacks that result from that emission.

To deny this overwhelming consensus is to deny gravitation, the heliocentric model of the solar system, or the spheroidal nature of the Earth.  Let me make it perfectly clear, however, that this is no way means that the consensus is correct.  Neither is this consensus unanimous.  There were clearly speakers and poster presentations that were contrary to the consensus, but they were in the minority by far.  Really far.

I don't expect that the random qualitative sampling I did today would be much different than any other days, but I'll pop in on the climate presentations over the next few days just to confirm.  If anything changes, I'll post an update.

The next time you hear someone forward the argument about a lack of consensus on AGW, tell them to go to the AGU meeting and collect some data.  There is only one conclusion that can be reached after such an exercise.  The conclusion is inescapable and irrefutable.  The overwhelming consensus is that AGW is here. There may be other arguments against AGW, but the "lack of consensus" argument is dead on arrival.

Monday, December 7, 2009

My Position on Anthropogenic Global Warming

I am often asked by friends and relatives about my take on Anthropogenic Global Warming (AGW), because I am an atmospheric scientist presumably with more knowledge and expertise on the subject than the lay person. I am also often hesitant to respond, because my current position on AGW is complex, full of caveats, and a careful explanation of such typically requires more time and patience than is available to me or the inquisitor. Below, I lay out my thoughts on AGW with as full an explanation as I can, complete with all the caveats. It is lengthy, but the written word allows for perusal at the reader’s leisure. I hope you will bear with me.
My overall position is that I accept the consensus view of AGW: there is a preponderance of the evidence that humans are causing an increase in global tropospheric temperature instigated by the combustion of CO2-producing fossil fuels. Now, don’t stop reading. Here come the first couple of caveats that some mischievous AGW opponent may be inclined to leave off in favor of selective quote mining.

Caveat #1: While I have the background to understand the complex science behind the AGW argument, I have neither the time nor the interest in poring through the immense and growing mountain of literature required to personally evaluate both sides of the argument. Doing so would require me to dedicate most of my waking hours to the subject, and I’ve got better things to do, including science that I personally find more interesting, albeit perhaps not as pivotal to our future on this planet. I have complete confidence in the brilliant scientists on both sides of the AGW issue that do dedicate their life to the subject; I’ll let them hash it out. Likewise, I have complete confidence in the scientific process; that is, the better scientific argument will prevail. The main point is this: I accept the veracity of AGW not because I have personally weighed both sides of the argument in any rigorous way, but because I accept the scientific method. I treat AGW no different than any other scientific area in which I possess insufficient knowledge to make a determination of veracity even though I may have the expertise or capacity to fully understand the area given a sufficient investment of time. For those that do not have the expertise or capacity to understand AGW, taking a position other than consensus is certainly illogical, as it would be for any other scientific question.

Caveat #2: I reserve the right to change my position on AGW as additional data and information become available. AGW is not a theory in the sense of the Law of Thermodynamics or Newtonian Gravitation. From the peer-reviewed literature that I have read on AGW, there are good arguments to be made on both sides of the issue. I personally know several very well respected scientists on both sides of the issue. For example, Dr. Roger Pielke, Sr. was on the faculty in the Department of Atmospheric Sciences at Colorado State University while I was in graduate school (he’s now at the University of Colorado) and I maintain a professional relationship with him to this day. He is a brilliant scientist and my interactions with him indicate that his ethics are second to none. He is also a vocal anti-AGW advocate (see his website for more info: in that while he accepts human-induced warming, he believes there are other significant forcings besides CO2. All is not resolved. Unlike evolution by natural selection, where religious creationists attempt to create a controversy where there is none within the scientific community, there is a real scientific controversy about AGW. There are two scientifically valid but opposing views on AGW and each deserves to be considered. Importantly, the weighing of this evidence must be done by experts via the scientific method, and specifically not by the lay person or the expert in the public arena. At present, the overwhelming consensus is that AGW is real.

I want to be very clear how scientific consensus is established. First, it is not established by petitions. Ever. Neither is it established by vote.  I was never asked, for example, as a member of the American Geophysical Union (AGU) whether I supported the AGU position on global warming.  Voting has its issues and does not allow for scientific argument.    How about the IPCC consensus?  Just because the IPCC has voted and come to a consensus does not make it a scientific consensus. Anyone who has ever been on scientific panels knows the politics behind them. I can easily put together a panel to give me the answer I want simply by excluding those opposed in favor of those that support my ideas. NASA does this all the time. In fact, it’s not uncommon for a NASA panel to be dissolved and then later reestablished (with different members) until such time as the chosen answer is delivered by the panel. There are also inherently conflicts of interest with many panels. Is it appropriate for the panel chair to oversee a panel that has a direct impact on their research? NASA mission science definition teams strongly influence the language that goes into solicitations for future missions. Is it any surprise that the solicitations have language that emphasizes the panels’ expertise in instrumentation often at the expense of others? Is it any surprise that many of the scientists involved in active missions just so happen to also be the very same scientists that helped produce the mission announcement of opportunity? Consensus is established over time in a slow motion duel of ideas as presented in peer reviewed literature supplemented by gray literature (i.e., conference papers). There is no quantitative measure or yardstick by which one can declare that scientific consensus has been met; it simply emerges, reaching the point where it becomes self evident. I am familiar enough with the literature and those involved in climate research to state that there is an overwhelming consensus. It is not unanimous! There are dissenters—honest to goodness dissenters with real issues and questions that have yet to be resolved. At this time, I have to go with the majority of experts. I have no qualms about changing my position if the consensus view, based on evidence, changes. I presently accept the veracity of AGW but with the knowledge that this could be a false position.

I would now like to throw in a little bit of commentary that is not directed toward establishing the truth about AGW. The first bit concerns the climate signal and the second concerns policy.

There is much debate in the literature and especially in the public arena as to whether the global temperature is increasing. The incessant debate over whether the temperature is going up, down or sideways misses the mark completely. The question should be whether there is an anthropogenic signal on top of the natural climate signal. If we were naturally heading into an ice age, it would be good to know whether humans might be slowing the progression. If we are naturally heading into a very warm interglacial period, it would be good to know if humans are accelerating the process. AGW, if true, operates regardless of whether the natural climate is warming, cooling, or staying the same. Antagonists of AGW sometimes suggest that the atmosphere has actually cooled over the last decade or two, or that it has periodically cooled and warmed over the last couple of centuries. This is irrelevant. What they need to do is show that cooling or warming can be entirely explained by natural variations. In other words, if the climate has indeed cooled in the last decade or sometime over the last decade, that is not sufficient to dismiss AGW. AGW opponents need to show that anthropogenic forcing did not offset the cooling. Doing this places them in exactly the same pickle that the AGW supporters currently find themselves; having to demonstrate complete mastery and understanding of the natural climate cycle. Likewise, it is not sufficient for AGW supporters to simply show the “hockey stick” temperature graph indicating a rapid rise in temperatures coincident with the onset of the industrial revolution. What this camp needs to show is that the temperatures are higher than they otherwise would have been. In other words they need to demonstrate that the natural climate would not have produced such a trend.

So, it seems that both sides need to establish what the natural climate signal is in order to determine whether AGW is true or false. Or maybe not. While some employ various complex signal processing techniques in attempt to tease out the different climate signals, would it not also be sufficient to determine the impact of rising CO2 under a range of reasonable natural climate scenarios? If the AGW supports could show that the temperature forcing is positive regardless of what the natural climate is doing, that should be sufficient. Likewise, if the anti-AGW camp can show that the forcing from CO2 is unimportant under a range of natural climate scenarios, that would also be sufficient. This is where models can help.
Although I do not consider myself informed enough to make a personal determination of AGW, there are some aspects of the subject in which I am generally able to make an expert assessment. One such area is that related to climate models, subject to the caveat below:

Caveat #3: Although I am familiar with climate models, I have never applied these models to the study of Earth’s climate. I have used these models for the purposes of terrestrial weather prediction (note: weather, not climate) and in application to the climates of planets other than Earth. I can provide no expert opinion on the specific application of the models to Earth’s climate, but I do have sufficient knowledge to understand the numerics and general principles of modeling, which are more or less universal constants for application to any planetary atmosphere, including Earth.

Much has been made that the climate models have difficulty reproducing past climate trends. Whether this is true is arguable; models do very well in some areas and less well in others. Still, it may be mostly irrelevant. Consider, for example, the climate of Mars.
We know that the climate of Mars has changed, and is likely currently changing. More so than Earth, Mars undergoes large orbital excursions due to the lack of a large moon to stabilize the orbit. These excursions produce variations in the magnitude and distribution of solar irradiance over timescales of thousands to hundreds of thousands of years—the so-called Milankovitch climate cycles. At times, the Milankovitch cycles likely result in water ice becoming stable in the tropical latitudes, as opposed to the poles where it is currently found. Changes in global temperature may also vary with the changes in solar insolation and the accompanying perturbations in atmospheric mass (most of which is CO2). Beyond these climate cycles, we basically have almost no idea of what produces other climate cycles on Mars, nor do we have much detail on what previous climates were like. For Mars then, we have a trio of problems. Not only do we not know the previous climate states in any detail, we cannot possibly test the Mars climate models (essentially Earth climate models with physical constants and processes appropriately modified for Mars) to determine whether they accurately reproduce the climate variations, nor can we be confident that the models have the necessary physics to reproduce the natural, long-term climate signal, whatever that may be.

Despite what sometimes seems like overwhelming and insurmountable ignorance about the Mars climate, substantial progress has and continues to be made. We are very confident that global temperatures rise when the atmospheric dust load is increased. This is a robust finding, and is independent of the trajectory of the Mars climate. It matters not whether Mars is warming, cooling, or holding steady. Dust produces a net warming of the atmosphere. We know this not only from observations, but also from models. Even though the Mars climate models are completely incapable of reproducing the long-term climate variations of Mars (and since we do not have any meaningful detailed information on these previous climate states, we would have no way of knowing the accuracy of the models even if they could produce such variations), we can use the models to assess how the climate responds to dust loading. The models do not need to reproduce the climate trend to establish the magnitude of forcing. Instead, the models must simply reasonably reproduce the current climate state. The difference here is in reproducing the climate state rather than time derivative of the climate state. The phrase “reasonably reproduce” is actually a fairly loose requirement. In fact, a simple time-independent, 1-dimensional model of the atmosphere--one with no atmospheric motion or variation in time whatsoever—is all that is needed to understand the basic climate forcing of dust. Going to a full 3-D time dependent climate model simply provides more fidelity but does not change the underlying physics or outcome.

So it goes for Earth. The natural climate may be heading off on some trajectory: up, down, sideways. Even though the models may not be able to reproduce this trajectory, it is still possible to use the models to understand how processes will perturb the trajectory. To me, this is the real crux of the AGW issue. It is not whether the Earth will warm, cool, or stay the same. It is weather humans are producing a perturbation on the natural climate. Consensus findings indicate that there is a human perturbation.

Now I turn to policy. Policy decision is, unfortunately, often entangled in the science of AGW. Whatever policy is enacted (or not) to deal with AGW has absolutely no bearing whatsoever on the veracity of AGW. If the consensus view of AGW is correct, than it is theoretically possible that policy could remediate (although not eliminate) the impact. If the consensus view is incorrect, than any implemented policy might theoretically be a costly folly. Enough of the theoretical, how about reality?

I have yet to see a credible proposal that will reduce CO2 emissions to inconsequential levels. Simply curbing the growth of CO2 emissions is not sufficient. The majority of the world has yet to industrialize, and it does, it will likely do so on fossil fuels. Reducing emissions from the industrialized countries may temporarily reduce the problem, but it will not solve it. There are billions of people in the rest of the world ready to take our place as oil, gas and coal consumers.

Further, is the increase of CO2 emissions sustainable? Can we continue on our pace toward doubling CO2 levels? Those who subscribe to the concept of peak oil may have something to say about this. Eventually, they say, the world supply of fossil fuels will run out, perhaps within the century. This will necessarily result in a reduction of emissions.
Associated with policy to counter AGW is the inherent assumption that a warmer climate is bad. There are obvious impacts if AGW is true: rising sea levels or perhaps the increase in prevalence and coverage of tropical disease, for example. On the other hand, large regions of frozen, agriculturally poor land might become arable. The opening of an arctic Northwest Passage could speed commerce and reduce the cost of products that advance the human condition. It is not my intention to argue one way or the other on this, but simply to point it out. If we were naturally going into an ice age, would AGW be bad? Or more fundamentally, is it bad to perturb the natural climate in any way, up or down?

The tragedy is that with the focus on AGW and the connection to fossil fuels the issues that ought to be front and center with respect to policy is lost. First, even without AGW, fossil fuels are dirty. Combustion of these fuels results in pollution that has been definitively linked to respiratory illnesses, acid rain, heavy metal poisoning of waterways, and the production of carcinogenic compounds. The drilling, extraction, transport and refining of oil is a dirty business with noticeable first order impacts that should be avoided. We should be reducing our reliance on carbon, and in doing so our emissions would automatically fall.
Another issue related to fossil fuels is that the money finances some of the most vile dictatorial and dangerous regimes around the world. It is in the best interest of those who believe in basic human rights to reduce and eventually eliminate world dependence on oil. Instead of spending trillions of dollars on wars in the Middle East, that money could have been put to better use funding alternative energy. Without petrodollars, terrorists would be hurling rocks from donkeys instead of training and coordinating overseas attacks on civilians. Iraq was funded by oil. Iran is funded by oil. The Saudis are funded by oil. Indonesia is funded by oil. Without oil, these nations are nothing but impotent.

In short, regardless of the veracity of AGW, we should be limiting our CO2 emissions. If AGW is false it is not a reason to continue our destructive ways. The AGW argument is not needed, yet it has become the focus on whether or not to reduce our dependence on fossil fuels. That is a shame.