Sunday, July 6, 2014

Visions of the Future

I am an avid consumer of the kitschy, dystopian, sci-fi movie.

Give me your misunderstood artificial intelligence, your ethically dubious eugenics, your post-apocalyptic pastiche--I'll eat it right up.

I've only recently realized, though, that this genre obsession is mostly driven by a fascination with the future.

I often find myself reading an article about current debates on gender equality or recent advances in stem cell research and wishing desperately that I could fast-forward a few generations and see how it all plays out. This is probably related somewhere in the depths of my subconscious to why I often glance at the last page of a gripping novel to make sure it has a happy ending, or read the entire Wikipedia synopsis of an old TV series before I decide whether to watch it. I can't help it--I just really want to know how things will end.

Luckily, when applied to thinking about the future of society (as opposed to binge-watching), the questions that this curiosity inspires start to sound a bit more noble.

What will the movements and evolutions of societal and physical systems that we see today look like in a hundred years? In a thousand? Will the arc of the moral universe bend toward justice? Will the world end with fire or with ice, or will it end at all? Will we sail off into the egalitarian techno-topia of Star Trek, or swashbuckle our way into the messy interstellar Western that is the Firefly universe?

I’m so enchanted with these hypothetical thought experiments, that a friend and I are organizing a film series for our colleges’ undergraduates, entitled Visions of the Future. We'll watch and philosophize over some of the great film conceptions of what’s in store for human (and extra-human) civilization: from Blade Runner to Wall-E

As it turns out, this futuristic musing is not entirely divorced from the kinds of questions asked by the climate science/economics/policy community. One of the questions that scientific review bodies like the Intergovernmental Panel on Climate Change must address in their Assessment Reports is how climate may change into the future. And one of the ingredients in that prediction is what decisions society will make over the next hundred years--what technologies we'll adopt, what societal values we'll espouse, how population will grow, etc.

In order to come up with scenarios for the 21st Century, the IPCC has used a few different strategies over its history. In the 2008 Fourth Assessment Report, the IPCC strategy was the following:
Step 1 - Envision several plausible storylines for how society might develop
Step 2 - Program those storylines into Integrated Assessment Models (IAMs), which are simplified economic and technological models of society
Step 3 - Use the IAMs to simulate the evolution of emissions of different pollutants in each of those storylines
Step 4 - Put the emissions from each storyline into global climate models to give a range of possible evolutions of the physical climate system

The storylines (known as SRES, for their provenance in the Special Report on Emissions Scenarios) that were looked at most closely in the 2008 report span a range of possible futures that will not sound unfamiliar to connoisseurs of the Netflix sci-fi section.

The storylines are separated into different scenario "families" within which there are a few variations:

The A1 Scenario Family -- Society develops very rapidly, with population increasing into the mid-21st century and then declining, but does so with equally rapid technological advances and greater global interaction, cohesion, and equality. The variations lie in what energy sources society chooses to rely on: fossil fuel intensive (the A1F1 scenario), non-fossil fuel intensive (A1T), or a balance between the two (A1B). The A1B scenario was the favorite of much of the IPCC analysis, perhaps because it seemed like the right balance of realistic and hopeful. 

The A2 Scenario Family --  Society stays heterogeneous (the taglines of this scenario family are 'self-reliance' and 'preservation of local identities'), with economic growth and technological advance remaining regionally confined. As a result, both occur more slowly than in the other scenario families and population grows throughout the 21st century.

The B1 Scenario Family -- This family is like the A1 family, but with the difference that the global economy transitions to being based mostly on the information technology and service sectors (i.e. our economies are based less and less on making stuff). We adopt global strategies for achieving economic, social, and environmental sustainability, and develop clean and efficient technologies. 

The B2 Scenario Family  -- This family is somewhere between the B1 and A2 families in terms of population growth and the rate of technological and economic advance. There's still an emphasis on sustainability and equity, but it's done at a local level rather than a global one. 

The IPCC scenario strategy has evolved a bit since the 2008 Fourth Assessment Report, but the ideas remain similar. The latest Fifth Assessment Report that came out last year uses Representative Concentration Pathways (RCPs), which describe the evolution of the atmospheric concentrations of pollutants rather than of their emissions, but span a similar range of futures.

Of course, there’s a lot of guesswork involved in predicting the future, and the scenarios don’t span nearly all of the possible trajectories for humanity. They don't include the possibility of climate policies, like those that assign a price to carbon that captures its environmental damages, which could drastically change society’s decision-making around whether or not to do things that emit carbon. They also don’t deal very well with discontinuities—sudden, large disruptions like wars or subprime mortgage crises.

Nonetheless, reading through the scenario descriptions when they were first published gave me the same sense of desperate wishing to know how it would all end. Which path do our decisions of today (after all, we're already a tenth of the way through the 21st century) point us down? Should we think more about what the evolutions of societal and physical systems that we see today will look like in a hundred years?

And, most importantly, how do we make sure it has a happy ending?

Sunday, June 8, 2014

The Hare to Carbon Dioxide's Tortoise

I have often gone looking for mental clarity in a good children's story.

During finals week in undergrad, I used to camp out in my university's School of Education library, where the collection of "juvenile" literature was kept. Between reworking Geophysics problem sets and rereading notes on Existentialism, I would duck between the tall, metal bookshelves and clear my brain with a few chapters from a childhood favorite--Sideways Stories from Wayside SchoolFrom The Mixed-Up Files of Mrs. Basil E. Frankweiler, A Wrinkle in Time. The simple syllogisms  and straightforward analogies to be found in the dim, quiet aisles of J/YA Fiction were an excellent way to refocus when a technical theory or philosophical concept had me thinking in circles.

Perhaps this is why, as I prepared to give a talk a few weeks ago, I found myself gravitating towards one of the best known children's parables to frame the context for my work: Aesop's fable of The Tortoise and the Hare.

As an acceleration in my research responsibilities has led to a deceleration in my blog posts, it's high time for me to introduce the focus of my research: black carbon aerosol--what I like to think of as the hare to carbon dioxide's tortoise.

There are many ways in which the relationship between black carbon and carbon dioxide and their interaction with the climate system reminds me of the hare and his reptilian rival. And I must admit, I'm rather fascinated by the hare.

The old fable tells the story of the overconfident hare--fast, flighty, and inconsistent--who challenges the slow-footed tortoise to a race, but loses when he brashly takes a nap halfway and wakes to find that his unhurried competitor has crossed the finish line ahead of him while he slept. The story is the very embodiment of "slow and steady wins the race," but has variously been interpreted as a warning against idleness and a reprimand of capitalism, among other things.

Although the tortoise wins the race, the hare would probably make for a much better psychological study.

So, let me introduce the protagonists of this version of the fable:

Carbon Dioxide in the role of the tortoise is a familiar antihero--the colorless, odorless gas that comes from fossil fuel combustion and warms the planet by trapping thermal radiation and preventing it from escaping to space. Once carbon dioxide is in the atmosphere, it takes from a century to millennia to remove it. Because it lasts for so long, it gets uniformly mixed in the atmosphere. In this way, carbon dioxide is slow, steady, and predictable.

Black Carbon in the role of the hare is a less notorious villain. It refers to the tiny, dark, solid particles that are emitted whenever something (fossil fuels, biomass, etc.) is burned without enough oxygen. It's basically the part of soot that absorbs sunlight, hence its first name, Black. It also warms the climate system (setting aside its complicated interactions with clouds), but by absorbing solar radiation rather than thermal radiation. In fact, it warms the climate by much more than carbon dioxide does per unit mass, but there's thankfully much less of it. These tiny particles last in the atmosphere for only about a week before they either fall out or are washed out by rain. Fast, flighty, and inconsistent.

Carbon dioxide will ultimately win the race. Even if we were to stop emitting carbon dioxide, it's long lifetime means that its concentrations in the atmosphere (what matters for the Earth's energy balance) would only decrease by about 10% over the next century. If we stopped emitting black carbon today, on the other hand, it would be gone from the atmosphere in a matter of weeks. These characteristics have made black carbon the target of United Nations efforts to reduce the short-lived climate pollutants--black carbon, methane, ozone--that contribute to global warming but are easier to tackle than carbon dioxide.

There are also some interesting geopolitical implications, though, of the difference in the character of our two protagonists.

Because Black Carbon doesn't last in the atmosphere for very long, it stays concentrated near where it's emitted--its distribution is spotty and localized, as opposed to carbon dioxide's more-or-less uniform one. And because black carbon interacts with sunlight, which is unevenly distributed from the equator to the poles, where it is concentrated matters for how much sunlight it absorbs and how much it affects the earth's energy balance. Because of this fact alone, the climate system cares about where black carbon is emitted in a way that it doesn't for carbon dioxide (not to mention the fact that black carbon can interact directly with cloud formation and regional circulation on fast time-scales in a way that carbon dioxide doesn't).

This adds an extra dimension to my earlier blogpost on the Ethics of Air, contemplating the ethics of pollution that we outsource to China through trade. Moving emissions of black carbon from one place to another through trade not only raises issues about who is responsible for those emissions (a concern that is also present with carbon dioxide emission), but also creates the added dimension that the climate response to those emissions may be very different in one place than another (a concern that is not present with carbon dioxide).

It is this mischievous, mercurial behavior of black carbon that fascinates me. Although the tortoise ultimately wins the race, the hare would probably make for a much better psychological study. Despite carbon dioxide greater importance to the climate system in the long run, I am still drawn to understanding the climate impact of black carbon, in all its heterogeneous, transitory glory. My research so far has touched on understanding how black carbon affects precipitation, clouds, and the amount of sunlight at the Earth's surface--little puzzle pieces in the intricate jigsaw of how this tiny, fickle particle can affect the climate.

So back I go to looking for the next puzzle piece and figuring out where it fits. Perhaps I'll publish my next article in the Journal of Geophysical Anthropomorphisms.

Sunday, May 11, 2014

A Climate Scientist's Catch-22

This Tuesday, the U.S. government released its third National Climate Assessment, which chronicles the current impacts of climate change in the U.S. The report is full of illuminating graphics and important information (anyone interested should check out the assessment website, linked above, which is very navigable and clear), but the overall message is that the U.S. is already experiencing measurable and attributable impacts of climate change and that the negative impacts greatly outweigh the positive.

After reading news reports on the assessment, a friend emailed imploring me, as a climate scientist and policy fellow, to tell her what we should do about climate change and mobilize our friends to do it.

This is a tremendously difficult question for me: what should we do about climate change? It's a tremendously difficult question for anyone, but climate scientists like myself get caught in an especially troubling Catch-22 when posed with it. My friend was asking about it on an individual level, but it got me thinking about the bigger question of what we as a society should do about climate change and how (if) climate scientists like myself can go about answering that question.

On the one hand, I have scientific knowledge and some policy experience that perhaps allows me unique perspective. This perspective is ostensibly objective, informed by apolitical facts about the way that the climate system and policy structures work. I also have lots of opinions about what we should do about climate change, but these are colored by my personal values regarding tradeoffs I'm willing to make and what I think is important.

Would we trust climate experts' other statements as objective, if they were simultaneously making subjective recommendations based on their personal values? Some argue that climate scientists damage science by advocating policies. But we also so frequently ask climate experts to tell us what to do, and if they are silent then we lose the arguably best informed voice in the conversation. Figuring out how to separate and balance the two is one of the great struggles of being a climate scientist (or an expert in any politicized field). Here's one climate scientist's approach, as well as a back-and-forth on the subject from the New York Times opinion page. I thought myself in circles just clicking between the various articles that other climate scientists have written on the subject.

On the day that the assessment came out, the American Geophysical Union hosted a conference call for its members with some of the key authors of the assessment. Listening in, I was particularly struck by one exchange during the Q&A portion of the call:

One caller rambled for a bit about his favorite method of capturing carbon dioxide before it's released into the atmosphere, before asking the panelists if they had advocated this method in the report. The panelists' response was one that I hear very often regarding assessment reports: the report is intended to be policy relevant but not policy prescriptive, and as such they listed all well-established methods but did not advocate for any particular one. The caller responded tersely with "well, I don't understand what that means" (after which the moderator diplomatically moved the conversation on to the next question), and I think this gets to the heart of an often under-appreciated subtlety of how we deal with climate change.

Climate experts* cannot strictly tell us what we should do about climate change. Climate science tells us what the impacts of climate change are and can tell us how various policy options might do better or worse at mitigating those impacts. Climate economics can tell us how much those various policy options might cost. Climate policy-makers can provide us with a range of policy options. But the choice of which path to take is a fundamentally value-driven question. Depending on what you think is important, you may think we should do nothing to address climate change, everything to address climate change, or anything in between. (Whether what you think is important is defensible or not is another question altogether.)

*I should clarify that, although I hope half-a-decade in the field has given me some advanced understanding, I'm at best en route to being an expert.

In that way, climate experts can tell us what we can do about climate change. But what we should do about climate change is a volatile substance that comes from the combination of what climate experts tell us and what we think is important.

The silver lining is that this theoretically means that accepting the science of climate change does not oblige you to any one course of action. Many people suggest that one of the root causes of climate skepticism, either of the fact that its happening or the fact that it's human-induced, is that skeptics disagree with the courses of action that are often presented as a necessary consequence of the science.

So perhaps this, at least at this point in my ongoing training, is my climate scientist response to the question of what you should do about climate change:
You should understand it--invest honestly and to your best ability in learning the facts behind it, what the impacts are likely to be, what the suggested policy options are, and what their pros and cons are. Resources like the National Climate Assessment website are a perfect way of doing this without trying to get a PhD in it. Then (and only then) you should use your own value system (being honest about what that value system is) to decide what, if anything, should be done about it.

In the meantime, I'll go tell my friend all of my personal opinions about what we should do about climate change.

Sunday, May 4, 2014

Planet A and Planet B

The end of this week found me in a room full of some of the greatest interdisciplinary thinkers around climate change--at a conference on "Historicizing Climate Change." As a sheltered physical scientist, I'm still not entirely sure what "historicizing" means, but the byline of the conference was "How will future historians discuss climate change?"

This question, as difficult as it is to wrap my head around, got me thinking about the really big picture of how we interact with our planet.

Prof. Richard Somerville, a venerable and now retired member of the climate science hall of fame, presented the conference-goers with a thought experiment:

We currently live on Planet A--a planet where we've burned lots of fossil fuels but also happen to have developed really powerful computers and satellites that have enabled climate science to answer a lot of the questions that society is now asking of it.

There isn't necessarily a reason why humanity had to evolve this way. We could be living on Planet B--a planet where we've burned lots of fossil fuels but also didn't invent advanced computing or satellite technology. When this was mentioned at the conference, the image popped into my head of a sort of reverse steampunk world of coal-fueled locomotives and questionable corset choices.

This is an interesting thought experiment to me. Perhaps it is just a lucky coincidence that climate science has "come of age," as Prof. Somerville put it, at the same time climate change pushes society to look to climate science for answers. Then again, society is only asking climate science these questions because climate science itself made society aware of climate change. Theoretically, though, we could have been aware of climate change without satellites or advanced computing--Svante Arrhenius, the 19th century Swedish physicist, theorized the greenhouse effect in 1896, and most of our measurements of longterm increases in carbon dioxide and temperature come from ground-based observations. We just wouldn't have had all the tools we currently have to fully visualize the problem, test our theories, and predict things into the future.

On the other hand, perhaps it was the development of a technology-minded society in which we wanted vast amounts of energy to do things like shoot satellites into space or run giant supercomputing centers that has led to the huge amount of fossil fuel combustion that happens today. Perhaps a society in which we didn't develop things like climate models is also one in which we didn't use fossil fuels heavily enough to create the magnitude of problem that climate models are useful in addressing.

All of this mind-boggling hypothetical musing reminded me of the Anthropic Principle, a pseudo-philosophical idea from astrophysics.

The basic idea of the anthropic principle is that we observe a universe that is well-tuned to our existence because that's the only way we could be here to observe it. For example, if the physical forces in an atom's nucleus were only slightly stronger, hydrogen would have quickly fused into helium in the early universe, and H2O wouldn't exist--a bit of a slap in the face for the emergence of life as we know it...and for the emergence of a consciousness that can question why the physical forces in an atom's nucleus happen to be such that water can exist.

Similarly, perhaps it's completely unremarkable that we happen to have developed a science that allows us to understand one of the great humanitarian challenges of our time, because if that weren't the case we wouldn't be wondering if it's remarkable.

Maybe (probably) this has all just been a completely arcane mental exercise, but it's at least a reminder not to take for granted that we live in a world in which climate science has been more or less able to keep pace with the questions we need it to answer.

We could be living on Planet B instead, and I don't like corsets.

Sunday, April 20, 2014

Finding Your Research Personality

I love a good Wes Anderson movie.

His humor is whimsical and slightly dark, his cinematography is vivid and fantastical, and his stories are a mess of intersecting character arcs and random tangents that somehow coalesce into a plot.

While watching Anderson's latest offering, The Grand Budapest Hotel, I mused on the mess of intersecting pursuits that frequently seem to characterize my life as a graduate student (with the hope that they will coalesce into a plot nearly as good as Anderson's).

This week has been a jumble of different undertakings: my co-organizers and I ran a biannual mixer and discussion forum for the Princeton Women in Geosciences Initiative; I went to a seminar on writing and reviewing academic papers; I helped an undergraduate with his senior thesis; I learned about China's energy development pathways. And sandwiched between all of these things, I tried to portion out my work time between my current dissertation research, revising my previous dissertation work, my policy project, and another project with some collaborators.

None of these things have immediate deadlines and each could easily occupy all of my mental space if I let it, but I had to figure out how to focus on one thing at a time and in what order (to be honest, it's an ongoing process).

Choosing how to spend my time has been one of the great challenges of doing something as unstructured as getting a PhD. After our general exam, we're essentially sent off into the blue to weave ourselves into fully functional academics. Deciding what it means to be an academic and what kind of academic I want to become has been an intellectual and existential struggle. My friend refers to it as "finding your research personality."

There are many different approaches to being a scientist. Do you value skepticism above all else and advance the field by scrutinizing other peoples' work for improvements? Or do you value collaboration? Will your great contribution come from digging deeply into understanding one phenomenon, or will it come from asking the hypothetical questions that get everyone thinking in a new way? Do you write your papers from beginning to end, or do you write the results first and then go from the middle out? Everyone has a different philosophy, and your philosophy may end up being very different from your advisor's or your institution's or even, ultimately, academia's.

I often struggle with corralling my wide-ranging interests into the standard metric of what constitutes a good academic, namely research productivity as quantified by number of papers published. I enjoy thinking deeply about climate science, but I also want to spend time doing things like organizing scientific dinner discussions for undergrads, or learning how to teach effectively, or running women in science organizations, or taking classes on policy and economics so that I can communicate outside of scientific circles. But what do I do if the things that I value don't align with the things that an academic job search values?

There's a thread on the online Earth Science Women's Network in which one scientist details how having founded a nonprofit organization to give high school girls experience in field research has worked against her in academic job interviews. Earlier this year, two public health professors at Columbia were fired for dedicating too much time to public engagement and not enough to securing grant funding.

Does the evaluating rubric of the academic community need to change to accommodate these different aspects of what makes someone a good contributor to the advancement of science in society? In some ways it is already starting to, with big funding agencies like the National Science Foundation demanding to see a robust explanation of the "Broader Impacts" of any scientific project proposal that crosses its desk looking for money. But this push has been met with no small amount of hesitancy within the scientific community. Do I instead need to change my expectations of what career path will make the best use of my skills and passions?

In one of the discussion forums at the PWiGS mixer this week, I voiced a guiding principle for myself that I'd never articulated or even fully thought through before then: I'm going to choose what to dedicate my time to according to my own internal value system, because in the end those are the only values that I will be able to defend. Whatever career path those pursuits lead me down will then be an honest representation of what I think is important.

Another student in the discussion encouraged me with a word of wisdom from none other than Albus Dumbledore, Headmaster of the Hogwarts School of Witchcraft and Wizardry. Dumbledore gives this gem of tough love to the Hogwarts groundkeeper, Hagrid, who has shut himself in his cabin during a particularly crippling bout of low self-esteem:

"Really, Hagrid, if you're holding out for universal popularity, I'm afraid you're going to be in this cabin a very long time."

Though I don't think the fictional wizard ever pursued a PhD himself, the quote was a reminder that the process of forging one's own research personality sometimes requires forgoing universal popularity.

My drama teacher used to repeat Walt Whitman's poem, To a Pupil, to each of his graduating students, and one stanza in particular has always stuck with me. In this process of finding my research personality, it is perhaps the call to action that I find most compelling.

Go, dear friend, if need be give up all else, and commence to-day
       to inure yourself to pluck, reality, self-esteem, definiteness,
Rest not till you rivet and publish yourself of your own Personality.

Sunday, April 13, 2014

The Ethics of Air

Of all the breaths that I've taken in my life, my favorites are those first gulps of fresh air when I step out of the airport at a destination. It's my first chance to breathe in the character of a new location or to inhale a favorite harbor's je ne sais quoi.

Even now, when I return to my hometown, that first taste of Texas air is like an elixir--warm, slightly humid, and profoundly comforting. In my family's home country of Trinidad and Tobago, stepping out of the Port of Spain airport brings with it a waft of diesel exhaust, sweat, and maybe a little hint of curry from the doubles stand--spicy, alive, and familiar.

I take those waves of sensory nostalgia for granted. This week, though, I came across this article in the San Francisco Chronicle that's been making the rounds on Facebook and that gave me a much overdue admonition on the importance of air.

The article highlights a recent piece of work from a Chinese artist, Liang Kegang, that consists of a sealed mason jar of French Alpine air, sold to the highest bidder for $860 in protest of China's poor air quality. The article also details a few somewhat less symbolic endeavors deriving from China's recent battles with air pollution, including one clearer-aired province's plan to sell canned air for visitors to take home with them and a Chinese entrepreneur who is already doing so.

The issue, though covered in a somewhat tongue-in-cheek way, is a bit disturbing to me. It seems fundamentally unsettling for something like clean air to be commodified (which, perhaps, was Liang's intended point). Is it problematic for clean air to be something that can be bought and sold, something to which some have access and others don't?

I suppose in some ways we already allow clean air to be bought and sold. Some people can afford to move out of areas with urban smog, while others can't. On the other hand, at least in the U.S., universal access to clean water is something that has been made a priority. Municipal tap water is safe to drink and you can get it for free at a restaurant or from a public water fountain. Why is the same universal access not applied to clean air?

All of this contemplation happens to overlap with some in-depth reading I've been doing of a recent paper that does a neat analysis of the amount of emissions of different air pollutants in China that come from exports to other countries.

The most striking result of the paper for me is summed up pretty neatly in the below figure.
The percent change in the surface concentration of the air pollutant, black carbon, due to goods being manufactured in China and exported to the U.S. from Lin et al. (2014).
The figure shows the change in one type of air pollutant, black carbon, (which also happens to be the air pollutant that my research is focused on) due to goods being manufactured in China and exported to the U.S. rather than being manufactured in the U.S.

There are a few interesting things going on in the figure. You can see that the U.S. has had less air pollution because of this trade, but that China has had more--in fact, way more than the U.S. has had less. This has to do with the "emissions intensity" of China's manufacturing--basically, much more pollution is emitted when one widget is produced in China than when that same widget is produced in the U.S. (because of difference in manufacturing practices, energy sources, etc.).

The amount of pollution in China due to exports to the U.S. is not a small amount, especially when you add in all the other types of pollutants besides black carbon. All together, more than 20% of all export-related pollution (which makes up 15-40% of all air pollution in China, depending on the type of pollutant) is due to China-to-U.S. exports.

This result takes on extra meaning in the context of that $860 jar of air. If a jam jar of fresh air costs $860, how much do we owe China? How much more would we have to pay for things imported from China if the cost of clean air were included in the price of the goods?

Even more thought-provoking to me are the studies looking at mortality due to air pollution. One such study from some Princeton authors shows that more than 700,000 deaths in East Asia in the year 2000 could be attributed to particulate air pollution. It would be fairly easy to use the same formulas to attribute some portion of those deaths to air pollution that comes from exports.

The debate over who is truly responsible for such deaths is ongoing. Is it China for not implementing better pollution reduction measures? Or is it the importing country for driving the need for production in the first place? But it regardless raises some important questions about the global commons that is our atmosphere.

We have an odd relationship with the air we breathe. We so frequently are completely oblivious to it, but every now and then, like when stepping out of those airport sliding doors, it reminds us of its centrality in our lives. 

Can we put a price on that?

Sunday, April 6, 2014

All the Rights and Responsibilities

The sun is shining (today, at least), it's finally above 40 degrees, and it's general exam season for the 2nd years.

The general exam is the first intellectual hurdle of the PhD. In our department, it's a two-part challenge: an oral exam during which you present the results of your first two years of research and field questions from the faculty, and a two day written exam during which you are tested over the breadth of coursework that you've completed to date.

The exam is dispersed across the last few months of our 2nd year Spring semester and determines whether we can advance from the Master's stage of our graduate work to the PhD stage. Those who fail can choose to attempt to retake the exam or to leave with a Master's degree. Our 2nd years are brilliant, and I'm sure will trounce the exam with flying colors, but it's still useful during the high stress to have a reminder of why we started down this path to begin with.

For me and others in my department, we came into this field because somewhere in our previous education the science of climate change entered our consciousness, and we found it fascinating, compelling, and unsettling.

Although my general exams are a year in the rearview mirror, this year's exam season has coincided with a period of heightened stress for me as well, with journal reviews, annual reports, and project meetings coalescing into a haze of take-out Thai food and late nights in front of the computer.

Which is why I was particularly grateful (in a bittersweet way) for the jolt of motivation that came in the form of the release of Climate Change 2014: Impacts, Adaptation, and Vulnerability, the second phase of the Intergovernmental Panel on Climate Change's  Fifth Assessment Report. This phase is one of three sections of the IPCC's latest report on the scientific basis of climate change, it's impacts, and possible approaches to addressing it. For a brief, clear overview of the report and its contents (complete with compelling infographics on the geographical distribution of climate change impacts), you can check out the Environmental Defense Fund's summary.

The release of the report has sparked a flurry of media coverage of the impacts of climate change, including an interview on NPR's Radio Times with Princeton's Michael Oppenheimer and Rutgers' Benjamin Horton and this feature on PBS' Charlie Rose with Oppenheimer, Columbia's Jeffrey Sachs, and Penn State's Michael Mann:
Around 13:10 in the Charlie Rose feature, Dr. Sachs says:
"We need to hear more solutions...Fear can open the eyes for at least a moment, but it can also get people to tune down or even tune out sometimes...I'd like to see some clear leadership about the things to do, because actually, there are a lot of specific things that would make a huge difference."
(if the embedded video doesn't show up in your browser, you can view it here)

His statement took me back to a meeting I had in the greenest days of my PhD career, when I was still touring universities to meet with potential PhD advisors in the different programs I had applied to.

On one visit, I sat down with Dr. Veerabhandran Ramanthan in his office overlooking the Pacific Ocean outside of San Diego. He's been part of a major push to distribute cleaner burning cookstoves in rural parts of South Asia to reduce black carbon aerosol emissions, which pose a huge health and climate risk. During our meeting, Dr. Ramanathan said something similar, but not identical, to Jeffrey Sach's statement--that climate scientists have done enough to delineate what is a rather disturbing global problem, and it's time now to start offering solutions.

What struck me about that mental juxtaposition was that Jeffrey Sachs' call for solutions was focused at policymakers and at the technology and energy sectors, not at climate scientists like Dr. Ramanathan. Jeffrey Sachs is a world-renowned economists and Michael Oppenheimer has more than two decades of experience in the science policy arena. They are well-qualified to grapple with the economic and political conundrum of addressing climate change, but not all climate scientists are.

Should climate scientists be responsible for offering the solutions to climate change as well as the science? On one hand, climate scientists are best equipped to determine if a solution is actually a solution from a climate standpoint. On the other hand, they are not best equipped to determine if a solution is most economically efficient or ethically just. On the third hand, as Sach's pointed out, though, presenting the often bleak realities of climate change without the prospect of constructive pathways out of the problem is a recipe for people to tune out of the science as well.

I could easily develop a veritable octopus of back and forth opinions on this. My undergraduate diploma conveyed my degree "with all the Rights and Responsibilities thereunto appertaining." Wouldn't it be nice it they gave us a list of what those rights and responsibilities were?

Until then, I can rest assured that my responsibilities at least lie with this take-out Thai food and another late night in front of the computer.