GML Seminars

In lieu of an invited speaker for the GML seminar, we are going to have an extended seminar on March 8th from 2:30-4pm with 5 speakers who will share their AGU or AMS presentations. The schedule is as follows:

Galen McKinley is Professor of Earth and Environmental Sciences Columbia University and the Lamont Doherty Earth Observatory. She is an ocean, carbon cycle and climate scientist. Her research focuses on the physical, chemical and ecological drivers of the global ocean’s uptake of anthropogenic carbon. Regional and global ocean and climate models, and data science techniques applied to large community-compiled datasets are her primary tools.

Professor McKinley earned a BS in Civil Engineering from Rice University (1995) and a PhD in Climate Physics and Chemistry from MIT (2002). Her postdoctoral work was at Instituto Nacional de Ecologia in Mexico and Princeton University. From 2004-2017, she served on the faculty in Atmospheric and Oceanic Sciences at University of Wisconsin – Madison. Selected honors include the 2020 Ocean Science Voyager award from the American Geophysical Union, 2012-2013 Defense Science Study Group, and the Class of 1955 Teaching Award at UW-Madison in 2011.

In addition to research and teaching at Columbia University and Lamont Doherty Earth Observatory, Professor McKinley frequently contributes to national and international scientific coordination, and to scientific advising for the US federal government. She also enjoys opportunities to share climate and ocean science with the general public.

The ocean has absorbed approximately 40% of industrial-age fossil carbon emissions, and thus has substantially damped climate change. Understanding decadal variability in the ocean carbon sink is crucial for accurate diagnosis of the global carbon cycle, and will improve confidence in future predictions. I use ocean models, machine-learning based reconstructions of the global ocean carbon fluxes from sparse pCO2 data, and theory to quantify recent decadal variability and to understand remaining uncertainties.

Ensembles of hindcast ocean models and ensembles of pCO2 observation-based products indicate globally-coherent changes in the sink since the 1990s. There was a sharp increase in the ocean sink in the early 1990s. Next, there was a decline to a sink minimum in 2001, and then the sink recovered. By developing an upper ocean diagnostic box model that replicates these variations, I can attribute these patterns to two external forcings: the variable growth rate of atmospheric pCO2, and the 1991 eruption of Mt. Pinatubo.

Ocean models suggest smaller amplitude decadal flux variability than do observation-based products. Observation-based products are based on very sparse pCO2 data, with only about 2% coverage of the global ocean. Thus, errors may be significant when machine learning is applied to extrapolate to full coverage. To understand these errors, we have created a testbed using four climate model Large Ensembles which we can evaluate extrapolation skill. Due to the very sparse sampling, we show that the amplitude of decadal flux variability is overestimated by all machine learning approaches. Thus, ocean models may not be significantly underestimating flux variability as has been previously suggested.

Clara Orbe is a Research Physical Scientist at NASA Goddard Institute for Space Studies (GISS) and an adjunct Associate Professor in the Department of Applied Physics and Applied Mathematics at Columbia University. Before joining GISS in 2018, she completed a NASA Postdoctoral Program (NPP) fellowship at NASA Goddard Space Flight Center after receiving a Ph.D in Applied Mathematics at Columbia University (2013) and a Bachelor of Science in Applied Mathematics from Brown University (2007). After completing the NPP, she worked as a research scientist within NASA’s Global Modeling and Assimilation Office (GMAO), where she focused on diagnosing and understanding constituent transport in the GMAO's systems and where she maintains a joint affiliation.

Dr. Orbe’s research interests are oriented toward an improved understanding of dynamics and transport in the atmosphere. While at GISS she focuses on guiding development of the higher vertical resolution version of the GISS climate model (ModelE), her research more broadly applies a range of theoretical and numerical models, as well as observations, to understanding fundamental problems in atmospheric dynamics and transport.

Dr. Klaus Lackner is the Director of Center for Negative Carbon Emissions and professor at the School of Sustainable Engineering and the Built Environment of the Ira A. Fulton Schools of Engineering, Arizona State University. Lackner’s research interests include closing the carbon cycle by capturing carbon dioxide from the air, carbon sequestration, carbon footprinting, innovative energy and infrastructure systems and their scaling properties, the role of automation, robotics and mass-manufacturing in downscaling infrastructure systems, and energy and environmental policy.

Lackner’s scientific career started in the phenomenology of weakly interacting particles. Later searching for quarks, he and George Zweig developed the chemistry of atoms with fractional nuclear charge. After joining Los Alamos National Laboratory, Lackner became involved in hydrodynamic work and fusion-related research. In recent years, he has published on the behavior of high explosives, novel approaches to inertial confinement fusion, and numerical algorithms. His interest in self-replicating machine systems has been recognized by Discover Magazine as one of seven ideas that could change the world. Trained as a theoretical physicist, he has made a number of contributions to the field of carbon capture and storage since 1995, including early work on the sequestration of carbon dioxide in silicate minerals and zero-emission power plant design. In 1999, he was the first person to suggest the artificial capture of carbon dioxide from air in the context of carbon management. His recent work at Columbia University as Director of the Lenfest Center for Sustainable Energy advanced innovative approaches to energy issues of the future and the pursuit of environmentally acceptable technologies for the use of fossil fuels.

When it comes to CO2 emissions, the world is on an overshoot trajectory. Any plausible effort in mitigation will likely fall short of achieving the 1.5°C or 2.0°C targets nations have set themselves. Very likely, future generations will have to repair at least some of the climate insults by taking back a large portion of the CO2 already emitted. The rapid drop in the cost of solar energy is a hopeful sign that CO2 emissions can be eliminated, but a transition to a carbon-neutral energy source can only stop the increase in CO2 concentrations, it cannot reverse it. Today’s emissions are about 40 Gt CO2 per year. On current trends, the last 20% of energy consumption that is hard to decarbonize, will grow to 40 Gt CO2 per year by the end of the century. Removal, of 100 ppm of excess CO2 from the atmosphere, would require capture and disposal at a rate of 40 Gt CO2 per year for 40 years. Meaningful CO2 reductions therefore require carbon removal technologies that go far beyond what biomass production can deliver.

Technology for carbon capture and storage are necessary to return the world to a safe climate. Direct air capture offers a route to carbon neutrality and negative emissions for returning the atmosphere to safe levels of CO2. If costs can be reduced, for example through mass manufacture of direct air capture units, the technology could operate at the necessary scale. Paired with renewable energy, direct air capture could provide the feedstock for sustainable synthetic fuels and chemicals. Combined with carbon storage, direct air capture can deliver the negative emissions to draw down excess CO2 from the atmosphere and remove the carbon waste we have dumped into the environment. Storage, which more aptly should be called disposal, must be safe and permanent, i.e., last long enough to prevent climate damage to future generations. Future use of fossil carbon must be contingent on removing an equal amount of carbon from the mobile carbon pool comprising the atmosphere, biosphere and hydrosphere. Carbon accounting and carbon regulations are critical for a successful transition to a carbon-neutral economy that can still provide the energy services people demand.