In Episode 54 of Forecast, Peter Cox from the University of Exeter gives Mike the inside story about how the “emergent constraints” approach is reshaping our ability to wring every last drop of useful information from climate models. It’s a two step process. First, using climate models, establish a relationship between something you care about in the future to something that is mechanistically related and for which we have modern/historical observations. Then, construct a meta-model that is constrained by the models’ varying ability to simulate the observed variable. Bob’s your uncle. It can be more complicated than that, but Peter’s genius is identifying, probing, and polishing simple nuggets of science, many of which end up published in Nature. And speaking of Nature, we kick it off by discussing the benefits of knowing and, let’s just call it, “handling” your editors.
In episode 53 of Forecast, Mike talks with Julia Pongratz from the Max Planck Institute for Meteorology about the role of land cover and land use change in the climate system. Julia began working on the topic with an unbelievable challenge: simulating the impacts of LCLUC over the past millennium. Now her interests encompass geoengineering, climate mitigation and model intercomparisons, with a focus on understanding the ever-complex interactions among biophysical and biogeochemical feedbacks. Also, Julia assures Mike that, unlike in Maine, the ticks aren’t too horrendous in Germany. Probably. At least in the big cities.
Kevin Anchukaitis from the University of Arizona is probably best known for his work on dendroclimatology, but this is changing quickly. Now, his broader interests in the connections among history, political science, archaeology, statistics, climate modeling, and forward modeling of proxies are increasingly mirrored within the broader field of late Holocene paleoclimate research. Now, it’s possible to bring together this astonishingly wide range of evidence to disentangle, for example, the influence of volcanic eruptions on climate and society. It ends up sounding like a golden age for climate science, if not for the extinct Monteverde golden toad, whose extinction Kevin showed to be due to a fungal disease coupled with natural climate variability. As always, with good science, you have to go where the evidence takes you.
Jana Sillmann has carved out a career working on understanding and predicting climate extremes — heat waves, heavy rainfall, atmospheric rivers. What combination of factors controls the occurrence of extremes, particularly in a changing climate? Jana and Mike hash through the underlying science — including the agonizingly slow pace of model development — and how society is affected by and responds to extremes. Jana’s background and pathway to her current position are equally fascinating: an idyllic childhood in communist East Germany, with mom teaching construction; exchange student in rural North Dakota, hosted by an accordion virtuoso; grad school in the US; realizing that a career with computers and coffee was preferable to field work; chance exposure to an inspirational talk by Mojib Latif; a PhD from the Max Planck in Hamburg; four years in Canada with people like Francis Zwiers; leaving Canada in response to the anti-science politics of the time (sound familiar?); finally, moving to what sounds like a fabulous position at CICERO in Norway, where, remarkably, society actually seems to fully support women in science. And the ideal science environment? A sprinkle of Norwegian funding for individual academics, a bit of German support for postdocs and grad students, and a splash of Canadian IT investment.
Music from the album Encounters by Metastaz CC-BY-NC 4.0. Includes the tracks Hashashin, Vampire, and Girl and Assassin.
Bill Boos and I have something in common. Neither of us is much of a long-term planner, but we both like to take advantage of opportunities as they arise. For me, this approach led to a switch from academia to editing. For Bill, it led to an in-process move from Yale to UC Berkeley.
Bill’s career had plenty of twists and turns along the way. Namely, we almost lost him to the dark side … a career in financial consulting at Anderson (now Accenture). Happily, that path didn’t prove sufficiently interesting, and Bill landed in a terminal one-year MS program at MIT, where he started his work with Kerry Emanuel. Except it wasn’t so terminal.
Post-graduation, Bill checked out the professional job market, but quickly found that:
The best job that I’ve interviewed for is not as interesting as staying in graduate school
Things started to click with Kerry, and Bill pursued work on fairly theoretical ocean and atmospheric dynamics. But soon after graduation he published a landmark paper suggesting that a strong Indian monsoon can be generated solely by the presence of the Himalayas: no Tibetan Plateau required. I found the paper fascinating when I handled it at Nature, and it certainly stirred things up in the monsoon community.
As I’ve mentioned on the show in the past, monsoons are endlessly vexing: tantalizing but ephemeral teleconnections; busted predictions; monstrous interannual variability; conceptually simple but terribly complex in the details. One approach to disentangling the mess might be, as Bill puts it, to start off with a clear null-hypothesis:
Can we disprove the hypothesis that this year-to-year variability is just random and we’ll never be able to predict it?
Answering the question would inevitably take a renewed focus on observations, a deep dive into reconstructing past variability, and improved dynamical understanding.
One area of low-hanging fruit — or at least fruit that could be reached by a long extension pole, perhaps while teetering at the top of a rickety three-meter wooden ladder, the base of which has long been under assault by termites — is monsoon depressions. These systems, a topic of much research in the 1970s-1980s, don’t look that horrendous in comparison to typhoons, but end up generating some of the most destructive storms. Why? Bill would like to know. Me too.
Gabe Vecchi is a world-famous atmospheric scientist with a pretty simple attitude to making progress: In order to do something, you need to do it. And Gabe’s done a lot!
He was born in Boston but grew up in Venezuela, and witnessed the country’s dissolution from an intellectual magnet for South America into a dystopian nightmare. Going into the interview, I wondered about Gabe’s perspective on the anti-science, inward-looking trends we’re now seeing in the US. Are we headed for the same fate?
At this point, it’s impossible to say. But what I can say is that Gabe’s enthusiasm for science is undiminished by current politics. It was, in fact, kind of refreshing to talk to someone outside of the Bay Area echo chamber in which I live. It’s good to see science (and home renovations and new jobs) remaining at the forefront.
Gabe’s grandparents immigrated to Venezuela from Italy, and he lived there until his early teens. Ending up as a scientists might have been inevitable:
I think having [an] engineer and artist [as parents] … the only natural outcome is to be a scientist
And even though Gabe began knowing, as he says, just about nothing, he went on to make some of the major advances in atmospheric dynamics, tropical cyclones and seasonal prediction over the past couple of decades, including the now-famous modeling of a reduced zonal circulation in the equatorial Pacific.
Working in the Geophysical Fluid Dynamics Laboratory, with brilliant colleagues like Isaac Held and Suki Manabe, played a part in Gabe’s success. But still, and as so often seems to be the case, some of the big findings arose almost by accident.
By working on the still-not-fully-cracked nut of estimating changes in hurricane frequency and intensity in a warming climate, Gabe and his colleagues ended up with a modeling system with seasonal skill in regional hurricane prediction. The field is now able to resolve the small scale interactions between hurricanes and the large scale environment. Probably, as Gabe says, they wouldn’t have gotten to seasonal hurricane prediction if they’d been trying to do so:
You can’t see things if you look at them directly
As always with forecasting/prediction, it is easy to get carried away. But Gabe has a healthy skepticism for all sorts of modeling, prediction included:
Skill when applied to the past tends to be higher than skill going forward
Most importantly, one should keep a careful eye out for wild-eyed optimism or irrational exuberance:
The better you feel about it the worse it behaves … the probability of misleading yourself can be very high
Now in a multi-disciplinary department at Princeton, Gabe is looking both forwards and backwards. Forwards, to a closer collaboration with the geochemical proxy community, to unravel some of the many competing hypotheses for modern processes. Backwards, to hopefully develop a state-of-the-art yet simple climate model that could be run in a desktop machine by any interested academic, rather than at a super-computing facility.
Either way, there is endless scope for peeking under the mossy rocks of science, or looking for the structural members that we still need to install:
The things that we already know are much less interesting … if I can find something that we don’t know or that is kind of broken, then that’s great
Today’s music is from the album Anthropomorphic by Sister Sadie’s Foundry. Vocals and acoustic guitar are by geochemist Mark Pagani, who passed away in November 2016. I knew Mark just a little bit, but enough to know that he had a raging passion for science and life. At the time, I didn’t know about his wild musical chops, but they’re impressive for sure. In some ways, Gabe reminds me of Mark, and I thought the music would be a great match for today’s interview. Clips are used with the kind permission of Teresa Pagani and Michael Powers. Songs are Coming up for Air, Dry Land, and Skull and Bones. I encourage you to check out the album — it’s great!
Alternative facts are much in the news. The idea is, of course, ridiculous. Some things are clearly facts. Pizza is delicious; cake makes me happy; serving a white Burgundy at 40 F is an abomination; you should never wear a backpack with a suit.
Much of climate science, however, is not what you would call a hard fact. Yes, we can begin with some facts, following immediately with a suite of questions on quantification and mechanism. Yes, the Greenland Ice Sheet is losing mass. But what is driving the variations in time and space, are there physical limitations to retreat rates, what are the constraints on ice sheets behavior from paleoclimate, what is the role of firn/cryoconite/black carbon?
Research moves to the open questions, which, to some, provides an opening to say that scientists don’t have the facts. For the immediate questions at hand, it is of course true that we don’t have the answers — that’s why there’s research! Let’s not lose track of the vast amount of knowledge, and the big picture facts, that we do have.
Rant over, at least for now!
Sometimes I don’t fully grasp the scope of what Forecast guests are doing until I have time to reflect, during editing or while writing the show notes. That was certainly the case with today’s guest, Nerilie Abram. Nerilie has astonishingly broad interests. She works with corals, ice cores, speleothems, and modelers on topics all over the world (literally!) from the past to the future.
Much of our discussion centered around the process by which Nerilie cracks open new topics: framing questions, conducting research, challenging her own ideas, and grinding through the review process. Over time, this is the work that ends up in the fact category. It takes, in addition to mad technique, stubbornness:
Science requires, for all sorts of reasons, people who are going to be able to stick it out in this game, to have that kind of determination … not just the skills
Facts are indeed hard to come by, and proxies can be particularly bedeviling, particularly if one takes the time to actually think about them:
When you’re dealing with indirect proxies, things can change that you’re not expecting
The geochemistry behind proxies is hard enough. Interpreting the data with physically meaningful hypotheses, and testing everything with compelling statistics — is even harder. Nerilie is doing all of this, on topics ranging from tropical ocean-atmosphere-coral interactions, Holocene climate, sea ice proxies, and hemispheric reconstructions.
All of which makes me think of Nerilie as the Danny Meyer of science. What, you’re running a restaurant in a museum now? Or in Nerilie’s case, what, you had a quick talk with Nick Shackleton and now you’re off to the British Antarctic Survey? Smashing!
And the field work. Oh yes, the field work. Plenty of people get into geosciences for the amazing field sites. Nerilie never said that she’s in it for the travel, but it couldn’t have hurt.
I like doing Forecast for a lot of reasons. I get my fingers into the entrails of science in a way that isn’t really possible from reading submissions. I hear some appalling stories, off the record. I’m caught up in the enthusiasm of scientists for what they’re dreaming of discovering in the next decade. But, maybe most of all, I get to ask all kinds of impertinent questions that would rouse the ghost of John Maddox if done during the course of normal editor-scientist interactions.
And so it is with my interview with Noah Diffenbaugh, one of the leading investigators of extreme events in a changing climate, and a friend for over 10 years. Getting to know someone in science, especially after grad school, is weird, as huge chunks of their being remain out of view. Indeed I am often reminded of the blind men and an elephant. Perhaps before I only saw Noah’s enormous feet and extravagant tail, without realizing his true self. I am not at all sure that I do now, but at least it is clear he is a pachyderm.
Noah grew up at the Mount Madonna Center, one of the intentional communities that erupted like mushrooms from the rains of the 1960s’ spiritual and yoga movements. Most withered under divisiveness, absolutism, and isolationism. Mount Madonna, though, continues to thrive. Yes, it was, and is, a yoga and communal life center. But it is not a cult. Instead, it is open to the outside world, and has grown to support a renowned school and series of cultural events.
Mount Madonna’s sense of openness and inquiry are a clear feature of Noah’s work and collaborations. Our work together, on topics like wine and climate, grew from a short chat in an elevator during an NCAR young scientist boot camp. In general, because it’s impossible to tell which collaborations are going to work out, Noah’s default is yes.
Saying yes has clearly worked for Noah. He spent time at Purdue and is now tenured at Stanford, one of the premier universities in the world (and a very tough place to get tenure). Noah’s involved in the IPCC, regularly consults with a huge range of public and private interests, and publishes in Science and Nature. The path to the top was clear, and swift.
Except, no. Noah was an undergrad premed at Stanford. Until he failed, spectacularly, Chem 31. Then it was, almost, a degree in religious studies. But, no. Earth Systems 10 proved riveting and, fortunately for the field (and my own academic career!), Noah turned to science.
At least for a while. Upon graduation, Noah returned to Mount Madonna. He taught at the center’s school but a broader direction eluded; restlessness grew; the benefits and costs of communal life came into sharper focus.
I essentially didn’t go through adolescence and didn’t really leave home until my mid 20s when I was already married and already had a kid
For a lot of us, grad school attracts because it is something to do that seems potentially valuable, interesting and fun, without having to make an absolute choice about what, exactly, you’re committing to. So it was for Noah.
I went to grad school, and I made my grad school decision, for all the wrong reasons … if I ever said out loud my motivation and what I was thinking … I don’t think I would ever get admitted
And leaving home, surprisingly, only meant moving a few miles from Mount Madonna to UC Santa Cruz. Noah eventually settled on paleoclimate research with Lisa Sloan, but only after considering other — and wildly unrelated — options.
Since then, I think the path has been clearer, and Noah has made major contributions to our understanding of extreme heat, among many other topics. Most of our conversation, however, had a decidedly philosophical bent to it, and we wrapped up with a discussion of how the US presidential election at least had the useful outcome of prompting Noah to think about how scientists communicate statistics.
We talked for almost two hours, and still did not get to a lot of topics I wanted to cover (being the chief editor for GRL, life as an academic in Silicon Valley, gender balance in science, non-governmental funding). Editing the interview down to something reasonable took me forever, but I wanted to keep as much as possible. I think the story of Noah’s path through life and science could prove useful, especially for young scientists starting out and wondering if any of your role models also wondered … what am I doing in grad school, why did I pick this advisor, why am I studying this topic, am I really this bad at lab work. Yes. Yes they did. You too might come out the other side.
I think I first learned of Rob DeConto when I saw his paper entitled Thresholds for Cenozoic bipolar glaciation, published soon after my arrival at Nature. Specific and testable thresholds for the initiation of large scale glaciation in Antarctica and the Northern Hemisphere? Interesting! Continue reading →