Tuesday, March 30, 2010

The Benefits of Health Care

As those of you who read this column regularly know, I'm not one given to posting my initial response to events. I prefer to let things percolate for a bit and try to flesh out all the implications. The recently passed health care legislation in the United States is no different. First of all, I would like to congratulate the US Congress for their work. They have made the health system much more fair, and took a stab at trying to slow the growth of costs, something that will benefit all in the long term. Universal health care is something we have enjoyed in Canada now for many decades. In recent years this has proved to be a boon for private industry; they do not need to spend as much out of pocket providing coverage for their employees located here as for those in the US.

Thus, this provides an excellent place to talk a little bit about the benefits that one might expect working as a postdoc or undertaking a PhD. In Canada, things are pretty simple: with few exceptions postdocs and PhD students are left to fend for themselves. In the US there is more variation. Typically, as university employees (RAs and TAs), PhD students and postdocs are entitled to some basic health care, subject to reasonable co-pays ($5-25 for a doctor's visit, $100+ for emergency rooms, in-network). In many ways this replicates the Canadian health care system, so long as you remain a student in good standing and continue to work a certain minimum number of hours per week. Rare indeed is the postdoc or PhD that covers regular preventative care, such as dental visits, or provides it to spouses and that goes for both countries.

While this all sounds good, make no mistake, as Robert Heinlein once said "There ain't no such thing as a free lunch." (TANSTAAFL) If you work in the US, the cost of providing benefits with a position is passed on to you in the form of lower salary then you might earn otherwise. In fact, I have heard of positions that have a "marriage penalty" of sorts in which a pay cut is the price of adding a spouse to a coverage plan. These losses can be significant, totaling thousands of dollars over the course of a year.

Still, the situation is more complicated. For cultural reasons, Postdocs and PhD students in the USA tend to make significantly more then their Canadian counterparts (for instance, US$25k is not an unusual 1/2-time Science RA/TA, whereas the most lucrative NSERC PGS-D pays only C$21k and does not come with a tuition waiver, like the US counterpart; likewise US postdocs typically start around $50k and go up from there, whereas C$40 is much more common here), even factoring in the higher cost of providing benefits. Thus any reductions in cost associated with the new legislation will only widen this gap and make US Positions more attractive.

Monday, March 22, 2010

Astrobiological Disparity: A Commentary on the International Year of Biodiversity



From left to right: Deinoccocus radiodurans, a hardy extremophile capable of life in nuclear reactors, middle, the strange body plan of the now-extinct cambrian animal Opabinia Regalis (As envisioned by Nobu Tamura), an afican wild cat (as photographed by Wikipedia user Sonelle). General Sherman, a sequoiadendron, the tallest tree in the world at 275 feet.

2010 is the International Year of Biodiversity, following up 2009, the International Year of Astronomy. This makes it a particularly good time to discuss the field that links these two subjects, Astrobiology. Much of astrobiological work today occurs along two linked themes. The first is assessing habitability and the potential for life elsewhere in the Universe. This is what we are trying to do by following the water on Mars. However, this endeavour cannot proceed without input from the second theme, understanding the origins of life and its early development on the earth.

Unfortunately, both of these themes face a fundamental problem. Even though there is great diversity between extant forms of life on Earth, there is remarkably little disparity, from a cosmic perspective. This difference is a subtle, but important one. While diversity is a measure of the number of different forms in a collection of organisms (usually taken as the number of different species, or non-reproductively mixing groups), disparity is an expression of the degree of differentiation between these forms often in terms of body plans and survival strategies. So a collection of 500 species of shrimp is more diverse, but less disparate then a collection of 100 species made up of plants, fish, crustaceans and plankton. Notably, neither measure takes into account any measures of the success of a particular species in terms of number of organisms, range, species longevity, etc.

Since we only have one example of a planet with life, it is worth asking: how disparate is life on Earth? While there may be as many as 100 million different species present on the planet today (most remaining as yet undiscovered), these can be divided into just three domains of life based upon the form of their constitutive cells. These domains are Bacteria, Archaea, and Eucarya. Yet even these large meta-groups have inter-relationships. Eucarya, the domain of which we and nearly all other macroscopic life are a part, is thought to be the result of a beneficial symbiosis between an Archaean and a Bacterium at some time between 1.7 and 2.7 billion years ago. More fundamentally, all three domains are based on the replicative abilities of a single polymer, DNA and share a common ancestor. Thus in terms of strategies for propagation, the disparity of life on Earth is zero!


The three domains of life with Archea in Green, Eucaryotes in Red and Bacteria in Blue. Note that all three domains share a common ancestor which would be located at the center of the tree. The close relationship between the Archaea and Eucarya is shown as a larger subgroup before linking back to the last universal common ancestor.

Part of the reason for this could be the surprising observation that while diversification increases in time, disparity actually tends to decline. For instance, Stephen J. Gould observes that the number of different body plans (loosely equivalent to the classification level of phyla) in animals present just after the Cambrian Explosion is significantly greater than today. Analogously, it has been hypothesized that several different biopolymers, including RNA, PNA and TNA might have been able to perform functions similar to that which is played by DNA today. All may have been present on the early earth, but DNA, having advantages, outcompeted all of these other forms. The history since has been written by the victorious molecule.

However, this also suggests that even on the earth there may have been greater disparity in the past and that had conditions been different, then the balance could have been tipped in favour of other forms or strategies. As a result, we are left contemplating not just where in the Universe we might find life that has been successful on Earth, but where other kinds of life, as yet unknown, might be possible. There are some theoretical bounds we can put on such a problem; however, I expect that this is an area in which we will be surprised by discovery in the future. As many prognosticators are aware, it is always a dangerous proposition to define the limits of the possible.

Instead, we can proceed by determining what factors will tend to improve the odds of life beyond the earth, based on our limited earthly experience. For instance, liquid water certainly helps the chemistry that we require to function. The presence of certain elements in particular Carbon, Hydrogen, Nitrogen, Oxygen, Phosphorous and Sulphur (collectively referred to as CHNOPS) are also helpful, allowing for systems that can replicate and store energy. Similarly the presence of an energy source to power cellular reactions is critical; both chemosynthesis and photosynthesis, in which energy is gained from chemical disequilibrium or radiation, are practiced on the Earth. This has led to the hypothesis that the powerful oxidants found in the martian soil by the Phoenix Lander could represent a power source for a martian biochemistry.


Above: a soil sample is collected for analysis. On Mars, solar UV causes oxidants to form in the soil, building up to as much as 1 percent by weight of the upper layer. Perchlorate, discovered by the MECA instrument aboard Phoenix represents a potential power source for chemosynthesis, if there is an organism available to metabolize it.

But the most important factor seems to be time. Over time, organisms evolve to move into new habitats that were previously empty. To illustrate this, consider that despite the incredible biodiversity on the Earth, certain niches remain unfilled. Why do the deserts or the summits of mountains not flower with plants and animals? Turn the question around and ask why the continental surface was barren half billion years ago? And why, before that, no animals, plants or larger creatures beyond bacterial colonies filled the seas?

It is worth keeping in mind that all of these biomes, including the terrestrial abodes not filled today, are far more clement locations for the kind of life we know then exists on Mars, Enceladus or Europa. That these are the leading candidates for life elsewhere in our Solar System underscores not only the difficulty of our Astrobiological quest, but also the fragility of life on our planet. It requires that we protect something so rare in all its diverse forms. This is the realization that is at the foundation of the year of Biodiversity.


From left to right: Earth, Mars, Europa and Enceladus (showing water plumes)

As a final thought let us consider what the evolution of intelligence on the Earth has meant for the survival of life on Earth. The fragility of life relates directly to three factors: environmental variation, diversity/disparity and range.

The effects of the first two factors are simple to grasp. The greater the frequency and magnitude of the variation in environmental conditions, the more difficult it is to maintain a stable system. Likewise, the more diversity and disparity there is amongst organisms inhabiting a particular region, the more likely that one or more species will be able to deal with the environmental variations that do occur.

Range, however, is the most crucial. By spreading itself over a large territory, life cannot be extinguished easily by isolated events. This is the advantage of large animals. We cannot tolerate the extremes that bacteria can, but we can deal with inclement conditions by adapting or moving on. Migration is a particularly good example of an adaptation unavailable to simpler life which allows the organism to derive benefits from a much larger range.

Intelligence is by far the best known means of increasing the range of a species. Through our use of tools and clothing, human beings now inhabit the entire planet and can claim a range in pressure, temperature, salinity, pH, you name it - larger than that of any other organism, bacteria included. As such, the Intelligence habitable zone (IHZ) for a solar system housing intelligent life is limited only by the availability of raw materials and energy; aside from politics and economics, there is no reason why humans could not establish a permanent presence on Europa or even further out in the solar system.

As such, we are the first organism produced by our planet with the capability to outlive the death of our Sun, four billion years hence. Thus spaceflight represents the most important adaptation ever produced by life on Earth, and it is an adaptation that we must not lose if we are to preserve life in our corner of the universe.


With the emergence of intelligent life, the habitable zone (HZ) increases in size. This larger Intelligence Habitable Zone (IHZ) shows how through the use of spaceflight and nuclear energy generation, it is possible to spread life to any location with sufficient raw materials, mainly water ice. Discarding waste heat is a difficulty which corresponds to the left edge of the purple trapezoid, but the right edge has no well-defined boundary.

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For an interesting introduction to some of the central questions posed by Astrobiology, I highly recommend the book Rare Earth (most recently, 2003) by Peter Ward and Donald Brownlee. For a more advanced read, try Lunine’s Astrobiology (2005), a tome well-worth close study. Those looking for background on questions surrounding the initial emergence and diversification of animals (more generally “complex metazonans”) are advised to consider Stephen J. Gould’s Wonderful Life (1990). As a note on the images, I have selected NASA or Wikipedia media wherever possible and have made an effort to attribute the base images. If I have missed something, please feel free to leave a comment or contact me and I will fix it! With the exception of the Phoenix and planetary images, assume all image content is covered under: http://en.wikipedia.org/wiki/GNU_Free_Documentation_License.

Tuesday, March 9, 2010

Why is Global Warming so hard to understand and respond to?


I attended a professional dinner on the weekend where one of the speakers was a University Executive who was formerly an engineering professor working on biofuels. As you might expect, he brought up the concept of global warming in his talk, but the way in which he explained it made it sound like the burning of fossil fuels raised the average global temperature through the heat generated by combustion and not through the increase in GHGs (greenhouse gasses). As a result, in the Q&A he had to fend off a number of comments that nuclear power was terrible from the point of view of global warming due to the enormous quantities of waste heat released.

While the speaker could obviously have expressed himself better, his talk got me wondering about why global warming due to the emission of GHGs is such a difficult concept to communicate to professionals and to the public. There has been no shortage of press on the topic over the last 20+ years. And while a majority of americans now believe that the earth is warming, the message about why isn’t really getting across. A recent poll found that 65% of people did not feel that human activity was to blame or weren’t sure. Worse, when John Keller, a colleague of mine at the University of Arizona, asked a group of undergraduates the best way to combat global warming in a multiple-choice survey, the top answer was by picking up beach trash. This does not bode well for the future.

Obviously, part of the problem is that many environmental causes, from pollution to overfishing to the ozone layer to global warming, have become conflated in the public’s mind. However, this hasn’t stopped concerted action in the past. For instance, the Montreal protocols of the 1980s that sought to curb the emission of CFCs and preserve the ozone layer was passed easily and by any standard has been wildly successful. So what is it that makes global warming different? Here are a few possible reasons which together suggest a “perfect storm” of confusion and inaction of sorts. I’ll cover reasons both why it is complicated to convince people and why it is difficult to spur them to action:

1) Complexity. The concept of a heat-trapping gas producing an effect similar to that inside your car on a hot summer’s day isn’t a difficult one. It’s when you get to projected effects that the mind starts to boggle; stronger hurricanes, less rain in some places, more rain in others, warmer climate in some places, colder in others, to say nothing of the biological effects real and claimed. As such, it’s very difficult to say with precision what the effect will be on a person living in a particular place and to measure that effect. This contrasts with ozone degradation where you can take someone out in the sun in a well-mapped area of depletion and show them that they burn more easily.

2) Size of the effect and Natural Cycles. Catastrophic increase in temperatures from today’s levels could be as little as a few °C. That’s less than the difference between night and day, less than the difference between yesterday and today, and much less than the difference between summer and winter. I’m sure that you could get almost anyone to agree that an increase in temperatures of 30°C would be bad, but getting people to believe that such a small change could be devastating is difficult. Worse, the increase is not monotonic; it’s not as if global warming will add 2°C to the daily high every day. Instead some years will be colder, in fact some decades will be colder than the decade before, even though the trend is towards higher temperatures. Thus, some preferentially use the moniker “climate change” since any change in the climate, heating or cooling, can then be attributed to the effect without confusion.

3) The challenge of thinking Long-term. By and large human beings are not used to thinking long term, especially not in terms of hundreds of years, our brains just aren’t built that way. This means that it is very difficult to avoid processes which are slow to build, even if we suspect that there could be a runaway or tipping-point effect out there. The same is true of hundred-year floods and storms. Eventually, the cultural memory of the event recedes.

4) Global Reach. If you put together a group of friends to clean up trash in the local park, you see immediate benefits in your life and the lives of those around you. However, global warming can only be combatted on a global scale, and we naturally feel less kinship the farther we go from our own community. Furthermore, there is the spectre that actions you take may in fact cause detriment to your own personal quality of life, even though they will benefit the planet overall.

5) Cost. Unlike CFC reduction, which was a relatively small change, economically, reducing the world’s carbon footprint is a monumental task. It will cost trillions to implement and change our daily lives. Potentially, it will change the job market and sap the economies of those countries that make it a priority, versus those who do not. This is true even though we will all rise or fail collectively. Since the cost to change is so high, the standard of proof demanded is thus correspondingly higher than for any other scientific issue.

6) Politics. Not surprisingly, the issue has also become a political one in which parties exploit public sentiment for and against global warming as a wedge issue. In December there was an entire episode of the McLaughlin group dedicated to the topic which discussed only the horse-trading around the issue and nothing of substance. You’re more likely to hear about global warming as a positive for energy security then for environmental reasons in the political sphere these days.

All of this makes global warming a hard nut to crack. I certainly don’t have all the answers. As a scientist I will continue to do my best to educate wherever possible. But things are starting to look a bit better. Attitudes towards wasteful behavior are changing and more technologies are coming online that can get us through. For instance, the world’s largest emitter of GHGs, China, is also the world’s largest investor in photovoltaics. That bodes well.

But I do not wish to encourage those who would try to convince by false claims or facile arguments. In particular, one famous youtube video shows a man making the following argument (“never refuted!”) which I have paraphrased: that because the possible consequences of global warming are so dire, it behoves us to spend mightily to prevent it whether or not we know if or why it will happen, or how bad it will be. How much should we spend? He doesn’t elaborate.

Unfortunately, governments and citizens are in the business of managing finite resources. Thus, money supplied to one cause has to come from somewhere else. Bjorn Lomborg, derided in many circles as “one of the greatest opponents of global warming,” does in fact list it as one of the most serious problems facing the planet today. However, as he says, there are many better ways to spend that capital that could have a larger impact on alleviating human suffering; a few hundred million to provide access to fresh water for everyone, even less to provide vaccinations, just to name a few. That’s the kind of calculated, sober and rational thinking the gravity of this topic deserves.

As a side note, why does a planetary scientist care? Because understanding the climate of the earth, how it works and what it has done in the past, may be the key to unlocking the past history of the climates of the terrestrial planets in general. For Mars this is an important problem. Did the faint young sun permit liquid water, and perhaps life to exist? The sinuous channels, deltas, and chemical/morphological evidence from the MER rovers say yes. But we don't know how long those conditions persisted. As well, we do not know if the large swings we predict in climate today could make it clement again for life on 100,000-year timescales. If so, then our chances for finding life on Mars are much better!

As well, if we wish to live on the surface of Mars one day, we will need to artificially induce global warming there. By knowing exactly what portion of the current trend on the Earth is explained by anthropological activities, we can more effectively warm Mars or determine if it is even possible (One study by Chris MacKay suggests that it would be quite difficult). This concept is known as Terraforming.

Monday, March 1, 2010

Citius, Altius, Fortius

After last night's closing ceremonies, all I can say is wow. What a finish and what a show. Kudos especially to our Canadian athletes who really finished strongly in the last couple of days with a record haul of medals. You had us worried there for a while! All congradulations aside, however, what I'd like to talk about here in this space today are some of the similarities and parallels between an endeavour like the olympic games and space flight.

Some of these are obvious. When you ask a kid what they'd like to be wheb they grow up, chances are that athlete and astronaut would both appear high on the list of most popular aspirations. As well, they both create great spectacle and highlight incredible human stories. No matter which one you are talking about, a veritable army of dedicated people, toiling for years, are necessary to pull the whole thing off.

Also, like the olympics, spaceflight will yield the highest returns if it is not the sole province of a single nation, or even a small few. It needs to be a truly international experience. Greater and greater collaboration across borders is occurring, but the flag on your passport still matters enormously. This is perhaps one of the greatest promises of commercial spaceflight, which may eventually open up this frontier to people from all nations.

So, could there be an echo to Jacques Rogge's traditional line from last night "I call upon the youth of the world to gather in four years..." for our endeavour?

While you ponder that, think about this: on a deeper level, both the Olympics and Spaceflight are expressions of our civic pride and are funded largely through the public purse. As such, both are run at what is essentially a loss. Today VANOC will reveal its balance sheet, and it's not expected to be good. The City of Vancouver has certainly paid a price for the honour of hosting the games. Many residents fought against the bid and boycotted the celebrations that took place. Likewise, the expenditure on NASA sometimes stirs a similar response. Kritoph Klover perhaps put it best in his song "Others Standing by" from the album "To Touch the Stars:"

'Why would you go there?' they say
'There's nothing up there anyways
We could use the money here
Don't you know that life's to dear?'

Neither hosting the winter games nor exploring are cheap endeavours. The obvious monetary returns in terms of new technologies (memory foam, anyone?) and sporting facilities can be hard to quantify exactly, and never cover the cost. So why do we bother with either?

I think it comes down to our nature as human beings. We all aspire to be more then we are. Life is not just the search for a just and comfortable existence. We need to believe in our ability, as a species to grow beyond what we are. To test the limits of what we can do. It's a big part of what made us the creatures we are today, and it is also key to our long term survival. That's worth a few dollars every four years. So, as the olympic motto says: Faster, Higher, Stronger! Or as Klover answers:

'We'll send the best from Earth
To find out what it's worth.'