Sonia Seneviratne on droughts, extremes, the IPCC … and laundry in Switzerland

I met Sonia Seneviratne from ETH Zürich at a climate conference way back in 2013. This was not long after she served as a coordinating lead author of the now-famous IPCC SREX report, which lit a spark under the field of climate extremes. Sonia tells me the back story of becoming a CLA, the ongoing challenges of quantifying changes in extremes — droughts in particular, and the need to communicate seemingly obvious climate science to a broader audience. We talk through some of the most pressing issues in modern climate science:  our chances of staying below 1.5 °C of warming without climate engineering, climate engineering with land-based albedo modifications, and the kinds of societal transformations needed for radical mitigation. And hanging out your laundry in Switzerland. Like climate, it’s complicated.

Sonia Seneviratne

Music: Lullaby for Democracy CC BY-NC 4.0 and Rotisserie Graveyard CC BY 4.0 by Doctor Turtle.

Jessica Oster on speleothem geochemistry

Speleothems — stalagmites, stalactites, flowstones — are a central tool for reconstructing past hydroclimate variability. But what, really, are they recording? Jessica Oster from Vanderbilt University walks Mike through the long, incredibly long, process of permitting, extracting, transporting, sampling, analyzing, and understanding the isotopic signals encoded in these bedeviling but transporting recorders.

Succeeding in the field requires incredible patience combined with the ability to think deeply about how the sparse but growing network of speleothems, combined with other hydroclimate records, can inform our understanding of past climate dynamics. And progress is happening. For example, Jessica tell Mike how she and her colleagues pulled together a sweeping collection of paleoclimate evidence to reveal how the jet stream contracted and twisted in glacial boundary conditions, rather than moving monolithically south.

One gets the sense that the community is, finally, approaching a broader consensus that speleothems are recording measures of atmospheric circulation and moisture source, not a pure amount signal. Maybe the simpler explanation would have been easier to parse, but the more complex interpretation also points towards the potential for a richer understanding of past climate dynamics in a range of boundary conditions.

Music: Hallon by Christian Bjoerklund CC BY-NC-SA 3.0.

Climate dynamics with Libby Barnes

Libby Barnes, like essentially no one else on Forecast, wanted to be a professor from age 12. Specifically, a physics professor. And indeed, climate science almost lost Libby to neutrinos. But an instrumentation disaster, and the associated personal mayhem in the research group, made Libby realize that she was geared more for solving a great many problems, not any one particular decade-long quest. Now, Libby is exploring a dizzying array of topics in climate dynamics, and we bore down into the long-running debate on arctic impacts on the mid-latitudes and subseasonal to seasonal prediction. Along the way, Libby tells Mike about her amazingly sensible — and highly intentional — approach to academia and the tenure process.

Libby Barnes

Music: Zopje, The Township Two Step, and HUA by Brazzmatazz are licensed under a Attribution-NonCommercial-ShareAlike License, as is this episode of Forecast.

The climate of Westeros with Dan Lunt

There’s incessant talk about impostor syndrome among scientists. But paleoclimate modeler Dan Lunt from the University of Bristol actually DOES pretend to be someone he is not. Specifically, Radagast the Brown from Tolkien’s Middle Earth and Samwell Tarly from Martin’s Westeros. Madness? Only if it is mad to spend what must have been a ridiculous amount of time researching and writing papers on The  Climate of Middle Earth and The Climate of the world of Game of Thrones. Dan tells Mike what’s behind this unusual outreach work, and some of the surprisingly interesting climate mechanisms at work (annual precession  cycles anyone?). The conversation wheels across Dan’s studies at Oxford, the incredible longevity of HadCM3, Earth system sensitivity, EMICs vs. emulators, model intercomparisons, the challenges of working with geologic data, and launching Geoscience Model Development. And finally, the life-long trauma of supporting a mediocre football club.

Dan Lunt from the University of Bristol

Reconstructing past sea level with Andrea Dutton

Andrea Dutton from the University of Florida tells Mike about the many nuances of using corals to reconstruct past sea level. Sounds simple enough: find corals at depth z, date them to year t, and Bob’s your uncle. Yeah … no. Turns out there’s a lot more at play: 3D topography, plasticity in coral’s depth preference, challenging geochemistry, changes in turbidity. The list of complicating factors is long, but Andrea and her colleagues are working incredibly hard to provide better constraints of sea levels during past warm periods — a critical constraint for the models being used to project sea level into the future. On top of all that, Andrea is an outreach superstar and was recently selected as one of Rolling Stones’ 25 People Shaping the Future in Tech, Science, Medicine, Activism and More. Professional success doesn’t always come easy, though, and Andrea has had to work through challenges like big publication gaps, divorce, and raising young children during the tenure process.

Music: The Professor’s Lab by Christian Bjoerklund CC BY-NC-SA 3.0.

Abby Swann on plants in the climate system

Abby Swann tells Mike how plants both respond to and affect climate change. Some of this seems obvious: more CO2, more photosynthesis, bigger plants. Maybe, but there’s a lot more to it: nutrient limitations (or lack thereof!), changes in respiration, stomatal conductance downregulation, drought responses, sea ice interactions, atmospheric feedbacks, changes in land cover … the interactions are complex and numerous. With her strong background in both atmospheric sciences and land-atmosphere interactions, Abby is ideally placed to be tackling these issues, and we talk through a lot of them. Abby, like many academics, has had to grapple with discussions surrounding sexual harassment, and we round out the conversation with a hopefully helpful discussion of how to at least frame supportive discussions within a research group.

Abby Swann

11th Graduate Climate Conference

In episode 58 of Forecast, Mike talks with Henri DrakeJennifer Carman, and Molly Keogh, three of the attendees at the 11th Graduate Climate Conference. The meeting itself is a great chance for grad students working on climate change — broadly defined — to get together with their immediate peers, away from, ahem, pesky senior scientists. The interviews span physical oceanography, wetland restoration, environmental psychology, education, and behavior change. A tiny window into the inspiring work being done by the next generation of climate researchers!


The launch of EarthArXiv

Tom Narock and Chris Jackson tell Mike about the new EarthArXiv preprint server.  The show is a bit of an oddball for Forecast, considering that the show’s usual diet is long-format interviews about a scientist’s life and research. But the launch of EarthArXiv — one of a growing series of preprint servers — could be the spark to light the  climate science community’s interest in the use of preprints, long a fixture of fields like physics and mathematics. For a discussion of EarthArXiv within the broader publishing landscape I encourage you to check out Victor Venema’s excellent blog post over at Variable Variability.

Music: Hallon by Christian Bjoerklund CC BY-NC-SA 3.0.

Corinne Le Quéré on the global carbon cycle

Deciphering the global carbon cycle is as fascinating as it is difficult. There are carbon fluxes in and out of the planet, all over the place, and at all time scales. Observational gaps are numerous and gaping. Uncertainties on country level emissions are increasing. Yet the global carbon budget is perhaps THE central bit of knowledge that society must have, if an informed decision on carbon mitigation is ever to be made. Corinne Le Quéré from the University of East Anglia is working to quantify — with enormous effort — just such a budget. You might think it’s like balancing a checkbook, and you’d be right. But only if your checkbook includes investments with unknown and time-variable interest rates, and frequent, untraceable withdrawals. As Corrine tells Mike, in spite of the massive challenges, the carbon cycle community is making tremendous progress in pinning down the many elusive processes that ultimately control the main variable of interest: atmospheric CO2 levels.

Music: Hallon by Christian Bjoerklund CC BY-NC-SA 3.0.

Joe McConnell on the scientific riches in tiny bits of ice

Most everyone you’ve heard on Forecast has a twisty career path. But Joe McConnell took an unusually circuitous route to his current role as a leading ice core scientist. Joe bombed as a dishwasher, thrived as a post-hole digger, started a consulting company as a teenager, considered anthropology and environmental law for his studies, switched gears to signal processing for oil exploration, traveled the world, returned to grad school with the aim of starting a hydrological consulting company, but ultimately returned to work on one of his enduring passions — the high latitudes. Now, Joe and his crew melt and analyze tiny bits of ice cores in one of the world’s premier continuous flow analysis labs. The samples are small, but the output is huge: major leaps in our understanding of black carbon, volcanism, and the interactions between humanity and the Earth system.

Joe McConnell, on Svalbard.