Tag Archives: climate

Vampires, Mummies, and Ghost Fears

by Shane L. Larson

By the time I went to college, I had mastered my fear of vampires enough to not have to sleep with my neck covered. Kept my kid sheets, mastered my kid fears.

When I was a kid, I was completely terrified of the dark. I would sleep at night with the blankets bunched up around my neck (to protect me from vampires) and with a bright light on all night long so if I happened to wake up, I’d see anything sneaking up on me.

Don’t get me wrong — I’m still terrified of the dark. I don’t do stupid things like walk into dark rooms without turning the light on, or watch horror movies (in case you’re wondering — 25 years is too short of a gap between viewings of The Exorcist). But as I got older, my fears evolved.

I grew up during the Cold War, and I was terrified of a nuclear holocaust — my nightmares of vampires were replaced by mushroom clouds and warheads unexpectedly raining down on Saturday morning breakfast. There was a lot of general malaise about this, but a particularly strong memory I associate with my burgeoning fear was seeing a 1985 Twilight Zone episode called “A Little Peace and Quiet“. The closing shot of that episode planted enough disturbing imagery in my head to fuel dark dreams for years to come.

The final terrifying scene in the Twilight Zone episode, “A Little Peace and Quiet.” The image of a warhead hanging over a town terrified me.

Today, I still worry about nuclear conflict (moreso lately, given the instability in the United States’ executive leadership). But other nightmares, possibly far more likely, have found purchase in the soil of my psyche. I worry about the resurgence of diseases like measles and whooping cough, the result of peoples’ resistance to vaccinations. I worry a lot about the steady and constant damage we are inflicting on Earth and its biosphere. I worry about the collapse of bee colonies and the massive bleachings of coral reefs. I worry that we see unprecedented changes in climatic patterns, atmospheric chemistry, and arctic ice that herald an uncertain terrifying future not just for humans, but for every lifeform on the planet.

There are lots of problems facing the world. (L) Rampant impact of human civilization on the environment. [Wikimedia Commons] (C) Coral bleaching, one indicator of planetary wide changes due to climate change [NOAA] (R) Viruses once held in check by herd immunity gaining footholds once again amid people disavowing vaccinations [Wikimedia Commons].

But none of this produces the same inconsolable dread in me as vampires. One of my friends was befuddled by this fact. She insisted that climate change and resurgent killer diseases were real threats that should terrify us, whereas vampires and ghosts are figments of our imagination. How could it be that I’m terrified by a figment of our imagination?

A peek inside my (irrational) nightmares.

She’s right — vampires and ghosts are a figment of our imagination, but as such there are no fixed rules about how to deal with them. There are as many ways of conquering and facing the supernatural as there are fiction authors.

But virulent diseases, arms control, and climate change? There are well established ways of finding out what’s at the heart of those threats and figuring out how to combat them. You and I call that science.

Where does my faith in science come from? A long and storied history, written by you and me and 40,000 generations of people before us. Humans, more than any other lifeform we are aware of, look at the world with a critical eye and ask “what do we see happening? what does it mean? what can we learn from this?” The result of that process, pursued relentlessly in the face of superstition and the over-active darkness of our imaginations, are all the wonders of the modern world we see around us — wi-fi and pacemakers and insulated coffee mugs and teflon pans land ballpoint pens and flying drones and digital cameras.

Technology is one of the most obvious manifestations of science in our everyday lives. Simple examples include insulated coffee mugs that exploit a deep understanding of thermodynamics (L), modern pens that utilize fluid dynamics and mechanical interfaces (C), and teflon coated non-stick pans are the product of chemistry and materials science (R).

But the process of science has also resulted in knowledge and discoveries that are as poetic and stunning as the finest piece of porcelain, the most beautiful rhythm of poetry, the most exquisite painting or the most stirring symphony. Consider the lives you and I lead — we live in a world where baseballs and rosebushes abound, we walk around at the pace our feet carry us, and the most extraordinary event most of us ever experience is a thunderstorm or a kiss on a first date.

Some of the everyday extreme events experienced by ordinary humans.

But that same world is a world where people like you and me have left footprints on the Moon. We’ve sent robots to sift the sands of Mars and photograph the far side of a remote icy world called Pluto. We’ve discovered that stars burn at millions of degrees in their hearts and when they die they explode, creating every atom in every cell of you and me. We’ve taken those atoms and broken them apart to discover they are made of smaller particles called protons, neutrons and electrons. We’ve even broken protons and neutrons apart to find they are made of even smaller particles, called quarks.

Well before science turns into ways to improve your golf game or make your life in the kitchen easier, it is simply pushing the limits of what we think is possible. [L] Buzz Aldrin’s bootprint on the Moon; the Moon is the farthest any human has ever been from Earth [NASA]. (C) The New Horizons spacecraft, after a 10 year journey, sent home the most exquisite images of Pluto ever taken. Pluto is the most distant object ever visited by spacecraft from Earth. [NASA] (R) We have the technology to manipulate and image individual atoms, a million times too small to be seen with your naked eye. [NIST]

We’ve got no business knowing any of that, because it has nothing to do with foraging for food, or making babies. It has nothing to do with sheltering from hail storms, or staying warm. It has very little to do with making clothes or making farm implements from rocks and sticks.

So why do we know about the Moon and Mars and Pluto? Why do we care about atomic nuclei and quarks? Because we let our imaginations get the better of us. Unfettered, we let ourselves ask any question we want to ask, and we set out to find the answers. Every time a curious question presented itself, we rolled up our sleeves and we figured out the answer. But discovery and understanding are only the beginning. Once we have the knowledge in hand, then our innovators and engineers can figure out how to bring it into our homes and lives.

That’s how science works.

In the end, science is the most powerful tool we have to solve problems, and we can use it to solve any problem in front of us. We should be convinced of that by the fact that we can visit planets that no human has ever been to, and that we manipulate and image the very atomic building blocks that make up the world even though we cannot see them. We have the ability to use these tools for our own good. We have the choice to use these tools to overcome those dark corners of our imaginations and create a future our children will look back on and remember for all the good that we did to save ourselves from ourselves.

The New Cold War

by Shane L. Larson

I was a child in the 1980s, during the climax of the Cold War.  I had always known about the Cold War, and knew in an off-hand way about the vast stockpiles of nuclear weapons. I had heard of the concept of “mutual assured destruction,” but I didn’t learn the fear associated with a nuclear holocaust until late one night in 1985 when I watched a horrifying episode of The New Twilight Zone, called “A Little Peace and Quiet.”

In that episode, a harried suburban housewife is digging in her garden and uncovers a magical amulet that, when worn, allows her to stop time by uttering the words “shut up.”  She predictably uses this excellent ability to bring some modicum of peace to her life, stopping the morning breakfast routine so she can enjoy her coffee and newspaper, and stopping throngs of crazy shoppers so she can navigate the grocery store.  The episode culminates late at night, with air-raid sirens going off and the Emergency Broadcast System blaring its baleful warnings about the onset of a nuclear holocaust.  Without thinking, our heroine demands that time stop, and the crisis freezes.  Stumbling out of the house in her dressing gown, she is confronted with the sight of a Soviet nuclear missile hanging in the sky over her town, moments away from destroying her and everything she knows.

That image of a nuclear missile, poised moments before detonation over a small American town freaked the crap out of me.  Thinking about it, I still feel the pangs of terror that raced through me as a boy.  That single image made the whole notion of nuclear destruction real to me.

Ultimately, the Cold War came to an end, largely through the advent of perestroika and glasnost in the USSR.  From an estimated peak of 70,000 nuclear warheads, that number has today fallen to around 25,000.  While the number is roughly a third what it used to be, it is still vast enough to rain unimaginable devastation down on the world.  The world’s fear level regarding nuclear weapons (at least those held by superpowers) has waned, but the level of perception held by the public regarding a nuclear holocaust is strong.  On the one hand, part of the public consciousness is built on visions built by television and film dramatizations such as “Fail-Safe” and “The Day After,” and novels like Pat Frank’s eponymous “Alas, Babylon” and William Prochnau’s “Trinity’s Child.”

More importantly, the effects of atomic warfare had been burned into the public memory after the atomic bombing of Hiroshima and Nagasaki.  Pictures and detailed medical reports concerning the injury and deteriorating health of survivors in the days after the bombings illustrate in no uncertain terms the punishing cruelty of death by atomic warfare.  More poignantly, the oral history of the event lives with us today through the eyewitness testimonies of Japanese citizens who had looked to the sky at the droning sound of the B-29 bombers that carried the first (and to date, only) atomic weapons to their detonation sites.  These oral histories have been documented in many books over the years, and in many instances can be read online (one famous collection of eyewitness accounts of the Hiroshima bombing is The Voice of Hibakusha, http://www.atomicarchive.com/Docs/Hibakusha/ ).

An attempt to illuminate the details of a full nuclear exchange were captured by Jonathan Schell in his 1982 book, The Fate of the Earth.  Written at the height of the Cold War, The Fate of the Earth captured with harsh candor the future of the world in light of a nuclear holocaust.  Portrayed in language that is decidedly non-technical and accessible, Schell outlines the physical consequences to our planet and biosphere; he explores the complex disconnect between scientific revolutions and the unpreparedness of society to deal with those revolutions; and perhaps most strikingly, he confronts face-on the almost certain reality that all our fiction and film dramatizations steadfastly ignore, the extinction of the human species.  The book is brilliantly written, and is often regarded as one of the seminal works about the threats to our civilization posed by the Cold War.

Today there is a New Cold War threatening our world, once again ostensibly based on ideology – this war is a war against science.  It is not a war framed by foreign powers vying for global domination.  No, this war is far more sinister, propagated by fuzzy thinking, authority based on personal opinion, callous disregard for facts and observations, and a fundamental ignorance about the process of science.  There are two focal points for conflict.  In one instance, the predictions of science conflict with deeply held, core ideological beliefs – certain socio-economic philosophies do not permit the acknowledgement of scientific data or predictions that conflict with their core tenets, particularly in our age of polarized and inflexible politics.  In the other instance, the predictions of science posit problems that have dire and far reaching consequences for our civilization – consequences so dire, that their resolution will require international cooperation and alliances, expenditures  of vast amounts of capital, and investments of intellectual effort the likes of which the world has never seen.  In both cases, the battle lines drawn against science are lines based on fear – fear of facing up to what science has to say about our future.

While there are many battle fronts in this war – evolution, stem cell research, vaccination, and many others – the most prominent battleground is centered squarely on the changing climate of the planet.  At the crux of this battle are some issues that can be tested, measured, and understood. The planet is, without a doubt, warming.  The understanding that the Earth is warming is not a matter of conjecture; the long term climatic data show that the planet is warmer today than it was a century ago.  That the Earth has gone through periods of warming in the past is not a matter of conjecture; climatic data from the geologic record show that the Earth has repeatedly experienced periods of warming and cooling.  That the warming seen on Earth today is at a rate that is far in excess of any previous known warming spell is also not a matter of conjecture; it is a matter of scientific fact supported by thousands of independent lines of evidence.  That the current warming trend corresponds temporally with the growth of industrialization is also not a matter of conjecture; it is fact.

The battle over climate is being fought over the implications of the temporal overlap of industrialization with the current observed warming trend.  The consensus of the scientific community is that our civilization must start making dramatic and immediate changes in our energy habits, particularly as they relate to the generation of carbon that is being dumped into the atmosphere.  As one might imagine, this has important and far reaching consequences for our energy-hungry culture.  Those consequences themselves have huge economic and political ramifications that have sparked a firestorm of debates.

Why are scientists so adamant that our civilization become more serious about controlling our carbon emissions?  Many believe that the correlation between the growth of industrialization and the current warming trend indicates an irrevocable link between humans and the changing climate.  But even for those who are less certain of the direct link, there are arguments that demand our civilization respond and curtail our carbon emissions.  One argument is the understanding that the climate is a non-linear system.  Non-linear systems are a well understood phenomenon in science – they represent interconnected situations where small changes to the physical conditions of a system can feedback on themselves and grow to drastic proportions.  You can demonstrate simple non-linear systems yourself at home.  Imagine having a stack of a child’s blocks.  Stacking two on top of each other is simple and stable.  If you continue adding blocks, short towers are stable but progressively taller towers are more wobbly. There will come a moment where the addition of a single block will cause a catastrophic shift in the tower’s configuration.  The climate is also a non-linear system; what is unknown is how unstable is it?  At what point will the climate reach an unstable point where simple changes will push it into a catastrophic and unrecoverable change.

The idea of an irrevocable catastrophic change strongly advocates for a course of action that can be described in terms of Pascal’s Wager, originally formulated by Blaise Pascal and published posthumously in 1669 in his last book, “Pensées.”  The Wager was a way to address the question of whether God exists or not, and is most easily thought of as a 2×2 box.  The columns represent the possible ways the world is designed – in Pascal’s case, these were “God Exists” and “God does not exist”.  The rows represent actions on our part, in Pascal’s case “Lead a pious life” or “Lead a hedonistic life.”  The entries are the consequences to us given the way the world is and the choices we make.  In Pascal’s case, if you lead a pious life and God does not exist then you only missed out on some sex, drugs and rock and roll, whereas if God does exist you’ll not suffer the fate of sinners.  If you lead a hedonistic life and God does not exist, then you had a lot of (perhaps immoral) fun, whereas if God does exist then your eternal soul will not have much fun.  Pascal used the wager to argue that in the face of any uncertainty in the existence of God, the only logical choice was to lead a pious life because the only bad outcome was for those who lead hedonistic lives.

In a very similar way, the question of human action and the climate can be framed as a 2×2 Pascal Wager.  The columns are “humans do not affect the climate” and “humans do affect the climate”, and the rows are “reduce our carbon emission” or “continue carbon emission.”  If we reduce carbon emission and we do not affect the climate then nothing untoward will happen to our planet, whereas if we do affect the climate then reducing carbon emission can prevent a headlong rush toward a non-linear catastrophe.  If we do not affect the climate and keep up our carbon emissions, then again nothing would happen to the planet (though the morality of our stewardship might be questionable), but if we do affect the climate then continuing to emit carbon will destroy the only planet we know that can support lifeforms as fragile as we.  Just as with Pascal’s original Wager, there is only one choice that has drastic consequences, so why would we avoid it?

While the scientific observations are clear, and the possible futures are certainly describable, the decisions about what to do are not so easy.  Mostly because those decisions are not matters of science – they are matters of philosophy, economics and politics.  The unfortunate truth is that the battles stemming from the philosophy, economics and politics have blossomed and, as with many conflicts, sought easy and soft targets.  In this case, science itself.  Why is science a soft target?  Because in the world today the understanding of science and the nuances of science are poorly understood and widely disregarded by an otherwise intelligent and capable population of citizens.

As was the case during the nuclear Cold War, many attempts to make the issues accessible to the general populous, to educate the average citizen, have been made. Many excellent books have been written explaining not just the science, but the politics of the situation: James Hansen’s “Storms of my Grandchildren”, James Gustave Speth’s “Red Sky at Morning”, and Tyler Volk’s “CO2 Rising”.  Many attempts have been made to create films about this topic, but they fall miserably short of being useful because they are subsumed in the modern entertainment machine where special effects and epic mayhem dominate the weekend box office.

But even if you could produce a film that garnered wide attention and praise, the world today is different than it was in 1982, and the effect of a single film or book on the public consciousness is perforce limited.  We are all dramatically linked through a global network of websites and social media.  Our news, rather that coming from a common source (the original triplet of national news networks), is garnered from a dizzying array of satellite and cable TV channels and online news sources.  This fracturing of the media means that we don’t all share a common source of information.  People can, and do, draw all their information from single sources that have been deemed philosophically appropriate, even if the information from those sources is contrary to all scientific evidence and based on an alternative knowledge system.  How can we ever hope to have a single unifying voice, like Schell’s book at the height of the First Cold War, in such a fragmented information culture?

And so we stand at a crossroads in the New Cold War, much as we did in the early 1980’s, when Schell penned his conclusion to The Fate of the Earth.  Curiously, his entire concluding monologue is devoid of almost any mention of nuclear weapons.  Reading it, one could easily believe it was written just today about the New Cold War and the battle over climate.  In his conclusion, Schell wrote of two paths, not unlike Robert Frost’s celebrated allegorical paths in the woods.  Then, as now, the paths represent different outcomes for the fate of humanity based on the outcome of the Cold War.  One path leads to extinction, while the other leads to survival of our planet.  His words are as relevant today as they were then: “One day – and it is hard to believe that it will not be soon – we will make our choice. Either we will sink into the final coma and end it all or, as I trust and believe, we will awaken to the truth of our peril, a truth as great as life itself, and, like a person who has swallowed a lethal poison but shakes off his stupor at the last moment and vomits the poison up, we will break through the layers of our denials, put aside our fainthearted excuses, and rise up to cleanse the earth…”

The Sustainability of an Unscientific Society

by Shane L. Larson

Some days, when I’ve been reading too much Edward Gorey and listening to The Cure at the same time, I imagine what it would be like to get a heart transplant.  “If I have to get a heart transplant,” I think to myself, “then the person I definitely want doing it is Fred Hansen, the proprietor and master cabineter of Intermountain Custom Cabinets.  Fred is a master artisan, well schooled in cutting things up and a master of joinery.  If he can put two pieces of oak together so I can’t even tell they are two different pieces, then surely he can do something as simple as stitching my aorta onto a new heart.”

On the surface, this idle daydream seems completely crazy, and it should.  Fred is not qualified to conduct heart transplants, though he knows about hearts and aortas, and has watched many documentaries on heart transplants on the Discovery Channel and seen a variety of Time magazine articles and news clips on CNN about heart transplants.  Fred knows enough to “talk some talk.”  And he knows how to cut and join things.  But in all likelihood, I should probably not put my life in his hands.

The first human to human heart transplant was conducted by Dr. Christiaan Barnard on 3 December 1967 in Cape Town, South Africa.  Barnard was a trained cardiac surgeon, with a deep experience in heart transplants based on a series of 50 previous transplants conducted on animal subjects leading up to the first human trial.  Despite early disillusionment on the part of cardiac surgeons after the invention of the procedure, technology and medicine have improved over the years, and cardiac transplants are now an accepted life-extending practice with some 3500 heart transplants conducted worldwide every year.  The population of cardiac doctors on the planet are a vital resource to the millions of people living their lives under the shadow of heart disease and heart defects.  If the cardiologists all vanished tomorrow, life would be much worse and in all likelihood shorter for millions of people, some of whom each of us know.

Cardiologists are one piece of the great puzzle of endeavours that makes modern society go, and play a role that they are uniquely qualified to hold.  Life on modern Earth churns forward under the auspices of a myriad of roles that single professions are uniquely qualified to hold: lawyers, diesel mechanics, longshoremen, electricians, dentists and cabinet makers.  Just as Fred knows a bit about heart surgery, all of us know some basics about the way our law system works and know not to stick forks in electrical outlets.  Our surface level knowledge of the world does not make us qualified to overhaul the engine in a 3500 HD Chevy Silverado or to install the electrical feeds in a new cell phone tower, though with enough training and study we could.

Where do scientists fit into the vast machine of society?  What unique role do they play, and in what way does science affect the inexorable churning of our civilization from today to tomorrow?  The root of the word “science” in Latin means “knowledge” and the practitioners of science are engaged in the systematic exploration of the natural world, expanding our knowledge and understanding of how Nature works and how all the parts of Nature are interconnected.  Like Fred and his penchant for surgical documentaries, some non-scientists know a lot about science.  Some take notice when the Large Hadron Collider is turned on underneath Switzerland and know that the generation of a quark-gluon plasma on the microscopic scales of the great particle smasher will reveal secrets about the origin of the Cosmos.  Some participate in the scientific enterprise by observing variable stars from their backyard or by letting their computer execute protein folding calculations while they are downstairs watching football.  There are awesome things that scientists do and discover every day, some of which ordinary citizens are very aware of.

But scientists, like cardiologists and teachers and auto-mechanics and insurance adjusters, are professionals who are uniquely qualified to address and solve particular problems by virtue of their training and expertise.  They are serious people who take their profession seriously.  The world collective of scientists has well defined rules by which problems are explored, debated and understood: experiments are conducted and the results reported, in the scientific literature.  The results are interpreted and debated, in the scientific literature.  New predictions are made and experiments built with the results reported, in the scientific literature.  Overwhelming statistical evidence is accumulated, in the scientific literature.  The collective scientific knowledge of humanity is reported and debated by scientists, in the scientific literature.  Results, theories and opinions which do not appear in the scientific literature have not survived the intense scrutiny and validation afforded by the collective mind and expertise of the scientific community.

The blogosphere, primetime television newscasts and Google are not the medium by which science is debated and communicated.  But here at the start of the Twenty-first Century, where science and technology are all around us and penetrate deeply into the fabric of our everyday lives, a large fraction of our society gleans their understanding and opinions about science through the filters of the blogosphere, primetime television newscasts and Google’s “I’m Feeling Lucky” button.  As a consequence, scientists and their profession are increasingly colliding with sectors of our society that find the process and conclusions of science to be disturbing, distressing and at odds with ideological beliefs.  Increasingly, science finds itself at odds with sociological forces which act out of enlightened self-interest and, increasingly, out of ignorance of the scientific process.  This filtering of scientific knowledge through ideological lenses, and the conflicting information that then propagates through common media channels, is a confusing muddle from which it is impossible to extract any truths.  For a huge segment of our society, this filtered muddle is their only exposure to science.  An entire generation of American children, who are already falling behind their peers around the world in math and science ability, spend their lives plugged in and glean enormous amounts of information from the multimedia circus.  The majority of society today is getting their scientific information from non-scientific sources, at a time when our lives increasingly depend on science.

Perhaps the most prominent example of this is the societal debate surrounding the Earth’s climate.  There are many questions about the Earth’s climate that have yet to be fully understood and answered.  If everything about the climate were completely understood, it would be a subject of record, not a subject of intense research.  But on the question of whether the climate is changing, the scientific literature outlines 28,000 independent lines of observational evidence that point toward the fact that the Earth is warming. Even if one line of evidence is uncertain, there are thousands of other indicators that point toward a warming planet.  This simple fact has brought the scientific community to a consensus — an understanding that the overwhelming evidence, presented and debated in the scientific literature, points toward a warming planet.  The idea of “consensus” has been twisted in the public eye to imply that there is uncertainty and wiggle room in the scientific data, an idea which lends itself well to the ideological polarization of our current culture. It has become fashionable to speculate on the veracity of climatological data when that data has been reviewed, vetted and debated in the scientific literature by the world community of professionals who are trained experts in the interpretation and analysis of such data.  Informing yourself on the nature of climatic data from people other than those qualified in the collection, analysis and interpretation of such data is tantamount to getting advice on heart transplants from someone who is not a cardiac surgeon.

Are there scientists who disagree and don’t believe in the consensus of the community?  Absolutely, and they should, because science does not move forward without the debate.  There are many famous examples of dissenting voices throughout the history of science.  Ernst Mach, one of the most renowned scientific minds of the early Twentieth Century, never believed in the existence of atoms, but the field of materials science grew and exists none-the-less, giving us teflon and polymer paints and carbon graphite tennis racquets.  Harold Jeffreys, a Fellow of the Royal Society and the Plumian Professor at Cambridge University in the 1950s, was one of the most distinguished geoscientists of the Twentieth Century.  He never believed in platetechtonics, but today high precision satellite monitoring and laser metrology incontrovertibly prove that the crust of the Earth is made up of plates shifting and sliding against one another, giving rise to earthquakes and volcanoes at the boundaries.  Albert Einstein was never comfortable with the idea of quantum mechanics, but we still have a semiconductor industry that uses quantum mechanics to make computer chips and feed our appetite for smartphones and Playstations and supermarket checkout scanners.  Being a brilliant mind does not mean a scientist is infallible; we are after all, still human.  Sometimes, unpopular views change the course of science and become accepted by virtue of experimental evidence.  But in the face of overwhelming experimental evidence and data, dissenters cannot argue the entire scientific community away from what Nature has revealed to us.  Science relies on the collective mind to insure that every nuance Nature has to offer is explored, investigated and understood.

Which brings us back to the way modern society approaches science.  In the United States in particular, our current culture of polarization has turned scientific data into an issue, something to be debated and argued about rather than something to be acted upon.  This is not a sustainable policy for our society to hold.   A society that does not embrace and encourage science cannot long endure.  If you take away plastics and electricity and modern medicine, life in the world begins to look a lot like the Middle Ages.  If you take away everything we know about the Earth’s climate and ignore the people who know something about the climate, the world begins to look a lot more like a nightmarish vision of Dante Alighieri.  It is a fallacy to believe that science is a matter of policy that can be debated and accepted based on what makes our leaders, almost all of them non-scientists, comfortable.  It is tantamount to asking Fred about doing a heart transplant.  But then again, I’m sure Fred has something to say about what’s happening to the Earth’s climate too.

Perturbations on Nature’s Design

by Shane L. Larson

At the end of the Cretaceous Period, 65 million years ago, a rock from space roughly 10 kilometers in diameter crashed into the Earth.  The result of that impact was an energy release equivalent to 100 million megatons of TNT and the excavation of a 180 kilometer diameter crater on the edge of the Yucatan Peninsula, known as the Chicxulub Impact Crater.  The outcome of that single astronomical event was the Cretaceous-Tertiary extinction event, in which nearly 75% of all plant and animal species that inhabited the planet died off, vanished from the face of the Earth forever.

This is not the only extinction in the Earth’s history, it is simply the most recent.  Based on fossil evidence, over 98% of all species that have ever been documented are extinct, exterminated from the Earth by the long slow march of history.  Looking around the Earth today, the planet is rippling with life, every nook and cranny of every ecosystem filled with plants, animals and microbes.  One can hardly believe that only 65 million years ago, a blink of an eye in geologic history, life on this planet had been decimated.  But biological systems are designed to evolve, trading entire species for mutation experiments in adaptability.

By all accounts, the Chicxulub impact was a serious event.  The deposition of 100 million megatons of TNT in equivalent energy into the environment had serious ramifications for the design of the Earth’s biosphere: the reptilian lifeforms that had ruled the planet for millions of years were snuffed out and replaced by a new experiment that has since had millions of years to expand and flourish.  We are living in a between time, going about our lifey-business until the next catastrophe pushes Nature toward a new design.  Fortunately for us, huge depositions of energy like the Chicxulub event are rare.  Right?

The prospects of another Chicxulub Impact Event are terrifying to ponder, but remote in prospect.  Based on the historical occurence of impact events on the Earth and the Moon, it seems the likelihood of a similar impact is roughly one per hundred million years.  But the Laws of Nature are broad in scope and aspect; it may be that all the Earth’s biosphere cares about is energy in any form, whether is comes in the shape of a rare astrophysical impact event, or some other seemingly benign trend.

Consider the loss in Arctic sea ice.  There is a concerted worldwide effort to monitor the change in ice levels in the Arctic and Antarctic, and the results are disturbing to many scientists.  Why?  One recent study reported the loss of 1400 cubic kilometers of the (formerly) permanent Arctic ice (Kwok & Cunningham, GRL 37, L20501 [2010]).  For a 1 kilometer thick ice sheet, this is an area roughly the size of Salt Lake City, seemingly small in comparison to the entire Arctic.  But how much energy did it take to melt 1400 cubic kilometers of ice?  An energy equivalent of 100 million megatons of TNT — the energy that was released in the Chicxulub impact.  Worldwide, there are ice melts of this magnitude in the glaciers, on the Greenland ice sheet, and on the West Antarctic Ice Sheet.  Worldwide, the warming of the coldest areas of the planet are indicative of energy shifts equivalent to many times that of the Chicxulub Impact.

By physical accounts, the Chicxulub impact made a small perturbation to the Earth, but in doing so wiped out the dinosaurs, creatures that had inhabited the Earth for hundreds of millions of years, unchallenged in their superiority and adaptability.  They are now all gone.  But Nature is adaptable in design, and replaced the failed ecosystem of the dinosaurs with a new one, the one we inhabit today.  Now humans are making similar subtle perturbations to the world.  Nature will have no qualms about wiping us from the face of the planet, a failed iteration in the 4 billion year old experiment in evolution.  The system is designed to discard the old, and replace it with something more adaptable. Who will our successors be?  What traits will Nature design to make them survive the new ecosystem we are creating?  Will intelligence be one of them?  Perhaps, perhaps not.  The robustness of Nature’s evolutionary machinery is awesome in scope, but ruthless in operation.  Looking at humans as one cog in the great wheel of evolution, it is unclear that Nature will decide that this thing that we call intelligence is a superior trait for survivability.