Tuesday, June 19, 2018

Secret Science Club Post-Lecture Recap: Astrobiology and the Anthropocene

Last night, I headed down to the beautiful Bell House, in the Gowanus section of Brooklyn, for this month's Secret Science Club lecture featuring astrophysicist Dr Adam Frank of the University of Rochester. Dr Frank is the host of NPR's 13.7: Cosmos And Culture and has recently released a book, Light of the Stars: Alien Worlds and the Fate of the Earth.

Dr Frank's talk riffed on the topic of the book- the research behind it came out of being a science writer who specializes in outreach. In the book, he wanted to address climate change denialism. An astronomer looks at what happens to planets undergoing climate change differently than a typical climate scientist. Regarding climate change, the problem can't be solved unless it is understood, and it can't be understood unless its story can be told. Anthropogenic climate change being a recent phenomenon, there is no broad story about it. The story that must be pieced together is: what is the human future on a climate-changing planet? Currently, there is an anthropogenically driven change in the planetary climate state from 'warm and moist' to an unknown state. Climate change will be accompanied by resource depletion, most dangerously, a depletion of potable water.

The effects of increasing carbon dioxide levels has been a source of concern since at least the 1960s, with President Johnson making this declaration in a special message to Congress in 1965:

"Air pollution is no longer confined to isolated places. This generation has altered the composition of the atmosphere on a global scale through radioactive materials and a steady increase in carbon dioxide from the burning of fossil fuels. Entire regional airsheds, crop plant environments, and river basins are heavy with noxious materials. Motor vehicles and home heating plants, municipal dumps and factories continually hurl pollutants into the air we breathe. Each day almost 50,000 tons of unpleasant, and sometimes poisonous, sulfur dioxide are added to the atmosphere, and our automobiles produce almost 300,000 tons of other pollutants. "

Currently, climate change denialism is another aspect of our political polarization.

In 2000 publication, Paul Crutzen and Eugene Stoermer coined the term Anthropocene (PDF) to describe the current geological epoch in which human activity is a fundamental driver of coupled Earth systems. Humans are altering the planet to the extent that researchers a million or two years in the future could be able to detect isotopic evidence of human activity. Humanity is pushing the levers on climate, biodiversity, the nitrogen cycle, and the phosphorous cycle. In 2009, Johan Rockström of the Stockholm Resilience Centre led an effort to describe the planetary boundaries within which humanity could thrive and to foster stability. Dr Frank described the Anthropocene with a wonderful turn of phrase: We have reached a mythic power regarding planetary change.

Dr Frank characterized his fusion of astrobiology and the Anthropocene as the 10,000 light-year view. Astrobiology is the study of life in an astronomical perspective. The difficulty in astrobiological studies is that it involves an N=1 problem because we only know of one life-bearing world. That being said, there were three revolutions in the field: the first being the discovery of exoplanets, the second being the exploration of the solar system, and the third being an exploration of Earth's distant past.

The existence of life on other planets has occupied the human imagination for millennia, with optimists and pessimists vying for public acceptance. Epicurus believed that extraterrestrial life was common while Aristotle believed that Earth is unique. Newton believed in extraterrestrial life, but by 1900, pessimism regarding life beyond Earth was ascendant. In 1995, NASA's Kepler Space Telescope detected the first concrete evidence of an exoplanet. Since then, planets have been found wholesale- almost every star has planets orbiting it, with one in five stars having planets in the Habitable Zone- that region around a star in which liquid water can exist.

The exploration of the solar system has proceeded apace, with all sorts of objects (planets, asteroids, comets) being visited. Climate is the generic status of all planets with an atmosphere, and climate models exist for the other planets of the solar system (PDF). Climate is a universal planetary phenomenon. Mars used to be a blue world, with a vast amount of liquid water. Dr Frank described its current state as hellish, a cold and nasty place, and joked 'bring your blanket!' He then noted that you can change your planet, it might not be the one you grew up on.

Dr Frank then showed us an image of various planets and asked us to identify them- they all turned out to be artists' conceptions of the stages of Earth's development, much like depicted in this gorgeous painting. At one stage, the Earth was molten. At another stage, before the formation of continents, the only landmasses were cratons. At another stage, it is believed that there was a Snowball Earth. During the Paleocene-Eocene Thermal Maximum, it is believed that Earth had no sea or land ice. Dr Frank quipped that the Earth has worn many masks.

The study of the Earth's past involves the study of many Earth systems: the co-evolution of the atmosphere, cryosphere, hydrosphere, geosphere, and biosphere. The Holocene, the geological epoch which encompasses our current Anthropocene, is one of many interglacial periods. AlL of human history has taken place in this epoch, approximately the last 10,000 years. Dr Frank posed the question, what would you experience if you landed on Earth three billion years ago? The answer is that you would asphyxiate because of a lack of oxygen in the atmosphere. The presence of free oxygen in the atmosphere is due to life- the Great Oxidation Event occurred when cyanobacteria 'farted out' oxygen as a waste product of photosynthesis. Life has changed the atmosphere over and over again. Successful species are numerous, but such success can lead to catastrophes- the cyanobacteria changed the atmosphere enough that it killed most of them off.

In 1979, James Lovelock and Lynn Margulis formulated the Gaia Hypothesis, the idea that the planet changes to maintain life. The hypothesis was controversial due to the notion of a teleological planet, a planet that 'wants' life, even though evolution is a blind processs. The idea of a 'living' planet led to some loopy interpretations in the public imagination, which led to some pushback, but it is undeniable that life plays an enormous role in Earth's systems dynamics. Earth and its life have been evolving together as a coupled system for a long time.

Dr Frank's research involves the study of astrobiological systems to determine if sustainable versions of our type of civilization are possible. Do industrialized civilizations like ours burn out in two hundred years? Astrobiological studies can inform us of new perspectives on our trajectory into and through the Anthropocene. How common are 'anthropocenes'? How fatal are 'anthropocenes'? What is the average lifespan of an industrial civilization? What are the characteristics of planets that survive an 'anthropocene'? Dr Frank urged us to take the prospect of exocivilizations seriously.

At this time, I will leave off the recap for now because bar trivia beckons- what good is learning while intoxicated if one cannot follow it up with showing off intellectually while intoxicated? I will finish this recap tomorrow...

By which I mean today!

Different stars have different characteristics. A star with a different spectrum from our sun would mean that photosynthesis on a planet orbiting it would differ from terrestrial photosynthesis. There are no tools in the toolbox to constrain our models focusing on the co-evolution of civilization and planetary systems. One definition of civilization involves the use of energy by intelligent lifeforms. A problem with studying astrobiology is the bad prosthetic forehead variety of science fiction- aliens provide a snicker factor. The search for extraterrestrial intelligence can be refined, as Dr Frank put it, "This is not your grandfather's SETI." Mentioning the excitement over the discovery of a possible extrasolarian megastructure, he exhorted us: "Consider the possibilities!" Within the next thirty years, we may have data relevant to the possibility of extraterrestrial life. For example, atmospheric signatures of industrial civilization include methane and CFCs.

The theoretical studies of exocivilizations involve a battle between optimists and pessimists. Astronomer Frank Drake formulated the Drake Equation, a theoretical exercise to estimate the possible number of detectable extrasolar civilizations, expressed as:

N is the number of detectable civilizations. R* is the average rate of star formation. Fp is the number of stars with planets. Ne is the number of those stars which have planets which can sustain life. Fl is the number of those planets on which life develops. Fi is the number of those planets which develop intelligent life which can produce civilizations. Fc is the number of those civilizations which have developed detectable communications technologies. L is the duration of time in which those civilizations release detectable signals.

Dr Frank posed the question: What sub-questions in the Drake Equation can be answered? Are we the only instance in cosmic evolution that intelligent life evolved? This ultra-pessimistic view would be a one in ten billion trillion chance. Even a pessimist like Ernst Mayr was ten million times more optimistic than that. Most pessimists would get a universe full of civilizations of two hundred years' duration.

Building world civilizations involves planetary feedback- 'anthropocenes' have probably happened before. We now know enough about planets and how they respond to to anthropocenes to begin how species will drive planetary feedback. Science is about constraining imagination, and the astrobiological/archaeological models are based on the predator/prey population models formulated by Lotka and Volterra:

Predator numbers tend to go up after the amount of prey increases, and crash after the prey numbers crash. Dr Frank used similar equations for population and planetary temperatures- he quipped that planets are machines, push hard enough and they go off. The models used for the equations were based on the population of Easter Island, as detailed in his May 2018 article in The Atlantic. Running multiple scenarios, he determined that there are three main results. The first is a mass die off as population exceeds the planet's carrying capacity. The second is the achievement of sustainability- a soft landing to a steady state is reached. The last is a true collapse, perhaps a runaway Venus scenario.

Dr Frank posed the question, what does the astrobiological perspective change? He joked that he is from New Jersey, so he is naturally combative, then noted that this is not a battle to save the planet- as Lynn Margulis joked: "Gaia is a tough bitch." The planet has been the scene of five known mass extinctions, and the only reason why we are here is because the non-avian dinosaurs went extinct, leaving ecological niches for our ancestors. What are we trying to sustain? What moral imperatives do we invoke to do so? Dr Frank showed the picture of the polar bear stranded on a melting ice flow and noted that it is an apex predator that would easily kill you. He then stated that humans can no longer practice ecological hooliganism. Even if humans are successful in reaching sustainability, there will be no more ice ages. Climate change poses a probably existential threat to the project of civilization, but Earth will survive even if we do not. Ecologically, the Earth's phytoplankton is more important than the charismatic megafauna usually invoked in ecological pleas.

Dr Frank urged activists to stop with the human hate- the goal should be to sustain the climatic conditions that are amenable to the project of civilization. Sustainability goals should balance a technologically advanced, energy intensive, high population with quality of life. 'Hockey Stick' diagrams won't change the narrative, stories are needed and the wrong story is 'we suck'. Cities are ecosystems just like forests, they have just been invented recently. The wrong question to ask is 'did we change climate?' The right question is 'what did we expect?' When oil was discovered, humans did not set out to change the climate, it was a mistake resulting from one particular sort of energy production. Our mistake now is to keep using fossil fuels. Climate scientist Raymond Pierrehumbert characterized climate change as 'Humanity's Final Exam'. Through right action and skillful means, we might just pass it. If we acknowledge that planets have rules, and achieve sustainability, we might create an 'awakened' planet on which the biosphere and civilization can flourish together, and the Gaia hypothesis can be realized.

The lecture was followed by a Q&A session. The first question involved mass extinctions, and Dr Frank noted that the biosphere would be happy to move on without us, and the burden falls on us to 'think like the biosphere' to benefit ourselves. Some bastard in the audience asked the good doctor for his opinion on the theoretical notion that a planet had 'one shot' to produce a high-tech civilization, because a failing civilization would 'spend all the startup capital' and impoverish any successors. Happily, Dr Frank's colleague Gavin Schmidt posed a speculative scenario in which a high tech civilization evolved millions of years before humanity. What sort of evidence would survive, say, thirty-five million years? Could climate change end one civilization and set up the cycle of fossil fuel production for the next civilization? Would a wind powered civilization be possible? What does a planet provide? What would our footprint be millions of years from now? It would be weird isotopic anomalies.

Regarding Mars, it is not Planet B. There is no way to move a mass of population and enough resources to sustain them to the red planet. Dr Frank then joked that we should 'fuck up' Mars- as we are triggering climate change, we are becoming spacefarers, and the price for climate change is the rest of the solar system.

Regarding the lifespan of technological civilizations, Dr Frank joked that, two hundred years ago, anyone traveling more than thirty miles per hour would be falling to their death.

Regarding the Fermi Paradox, Dr Frank noted that SETI funding has been slim, and that, if space were an ocean, we have only looked at at thimble. If there were aliens which could travel at approximately the speed of light, they could have disseminated throughout the galaxy in six thousand years, but if they had visited Earth, any traces would have been lost, so researchers should (shades of Arthur C. Clarke) look on the moon. I have my own theory about the Fermi Paradox.

Asked for the most effective story about climate change, Dr Frank opined that climate change shows us how powerful we are. He advised us not to bother talking to hardcore climate denialists, and noted that carbon dioxide doesn't care who you vote for.

Regarding Easter Island models, he noted that in most cases the population of the island exceeds its carrying capacity... sustainability is almost impossible. Carrying capacity studies for the planet use real climate models, with the parameters being based on energy sources. Even using wind power as a parameter, a two-degree change is expected. He noted that doctors don't only study sick people, and that many models are needed.

Asked about what technologies are needed, Dr Frank noted that we must get off fossil fuels and develop renewables. He noted that, near his Rochester campus, there are four bits of transportation infrastructure: the Erie Canal, a railroad, a highway, and an airport. Infrastructure changes, technologies change.

Dr Frank delivered a really great lecture- while much of it was speculative, it was a valuable intellectual exercise, and a call to action. I particularly dug the almost Lovecraftian evocation of vast periods of time, unburdened by Lovecraftian cosmic indifference and other less pleasant baggage. This was a superfun think piece. Kudos to Dr Frank, Dorian and Margaret, and the staff of the beautiful Bell House. Here is a video of Dr Frank discussing his new book:

Pour yourself a libation and soak in that SCIENCE!

ADDENDUM: Here is a short, sweet video featuring Dr Frank:

Now, that's a quick shot of SCIENCE!


Michael Hyatt said...

Are you familiar with the Drake equation? Because it's all right there. A set of variables to allow you to estimate the likelihood and perhaps the number of intelligent, spacefaring civilizations in the galaxy or universe.

The final variable is the most interesting from our standpoint - the lifespan of and intelligent, spacefaring civilization. Because now that we are one - the sample size of one that you noted in your post - we can see that getting here from agricultural roots through industrialization to technology did tremendous damage to the ecosystem and depleted planetary resources at an unsustainable level.

So that makes it interesting to think about in four dimensions - at any given time there might be 10 or 25 or 50 intelligent spacefaring civilizations in the galaxy, but they are regularly dying out due to pollution, resource/food scarcity and war. Of course, there may be another 100 planets evolving intelligent life to replace those, but is there a way to get to where humans are now without destroying the ability of the planet to sustain that intelligent life?

The parallel question is around the number of intelligent beings a planetary ecosystem can support. A necessary outgrowth of industrialization is curing disease and extending lifespan, which allows for more of a given species to live longer. Soon there are more of them than the planet can support in a sustainable manner, so resources are depleted at an accelerating rate and toxic pollutants are massively increased...

Big Bad Bald Bastard said...

The Drake Equation and Fermi Paradox came up. I think the Fermi Paradox can be explained by ‘Make Proxima Centauri IV Great Again’.

mistah charley, ph.d. said...

1)As always, your thoughtful report on the evening is thought-provoking. A couple of weeks ago I saw Adam Frank's latest op-ed in the NY Times:


I am fourth in line to read his recent book when my local library system gets it.

2)My hope is that humankind comes through the impending period of rapid change not only surviving, but with our scientific and technological abilities preserved. On CNN yesterday morning former astronaut Leroy Chiao spoke about efforts to detect and eventually deflect space rocks that might have a major impact on the planet. Surprisingly, he gave an incorrect number about the last extinction-causing event - '300 million years ago', he said - twice. Actually, the Yucatan impact in question was a mere 66 million years ago. I wrote him about this error, but have received no acknowledgment from him so far.

3)One hopes wiser heads will be able to mitigate the impending catastrophe - those around at the time will see how it goes (not I - I have perhaps 20 years left, at most). From a Wikipedia summary of a Cosmos episode, hosted by Neal DeGrasse Tyson:

"Tyson then notes that humans have discovered means of harvesting solar power, such as Augustin Mouchot's solar-driven motor in the 19th century, and Frank Shuman's solar-based steam generator in the 1910's. Tyson points out that in both cases, the economics and ease of using cheap coal and oil caused these inventions to be overlooked at the time. Today, solar and wind-power systems would be able to collect enough solar energy from the sun easily. Tyson then compares the motivation for switching to these cleaner forms of energy to the efforts of the Space race and emphasizes that it is not too late for humanity to correct its course."

From the abstract to Jon Kabat-Zinn's "Some reflections on the origins of MBSR, skillful means, and the trouble with maps", Contemporary Buddhism, Vol. 12, No. 1, May 2011:

"The author recounts some of the early history of what is now known as MBSR, and its relationship to mainstream medicine and the science of the mind/body connection and health....He locates these developments within an historic confluence of two very different epistemologies encountering each other for the first time, that of science and that of the meditative traditions. ... The author's perspective is grounded in what the Zen tradition refers to as the one thousand year view. Although it is not stated explicitly in this text, he sees the current interest in mindfulness and its applications as signaling a multi-dimensional emergence of great transformative and liberative promise, one which, if cared for and tended, may give rise to a flourishing on this planet akin to a second, and this time global, Renaissance, for the benefit of all sentient beings and our world." [end of quote from Kabat-Zinn]

Another American Zen teacher, Shinzen Young: "Science has beauty, depth, power, and practical utility. I believe that the two most impressive discoveries of our species are the Eastern method of meditative exploration and the Western method of scientific exploration. Some people claim that meditation and science have mated, but I think they are just starting to date. I believe the true mating will occur sometime later in this century and will give birth to a world-transforming paradigm shift."