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Search every verified Susan Hubbard interview, podcast appearance, and on-the-record quote — each transcript cross-checked by AI and human review to confirm speaker identity. In 2016 and 2017, Susan Hubbard, then Associate Laboratory Director for Earth & Environmental Sciences at Lawrence Berkeley National Laboratory, gave two lectures on the effects of climate change on watershed dynamics and permafrost. She stated that the Arctic is warming faster than any other place on Earth and that permafrost stores more organic carbon than all other global soils combined, twice as much as is in the atmosphere. Hubbard noted that as the active layer deepens, it could expose microbes to bioavailable carbon, potentially releasing a large pulse of greenhouse gases. She described uncertainty in how terrestrial ecosystems will evolve, with some models predicting they will become large carbon sources and others predicting they will remain carbon sinks. Hubbard discussed using geophysical methods such as ground penetrating radar and electrical resistance tomography to estimate snow thickness, active layer thickness, soil moisture, and permafrost characteristics. She reported that in ice-wedge polygon landscapes, polygon type had more explanatory power for variability in properties important for microbial activity than smaller features like polygon centers or rims. Hubbard also described a genome-enabled reactive transport watershed simulator that improved prediction of carbon export to the Colorado River by 200% compared to conventional models, and a scale-adaptive modeling approach using mesh refinement to simulate processes where they contribute to larger system behavior.
“The Arctic is warming faster than any other place on our Earth, and that active layer is going to get deeper and deeper, potentially exposing microbes to very bioavailable carbon which will lead to a huge pulse of greenhouse gas into the atmosphere.”
“There's a lot of uncertainty in how terrestrial ecosystems will evolve in this coming century; some models predict ecosystems will be huge carbon sources, while others predict they will remain carbon sinks.”
“Permafrost stores more organic carbon than anywhere else in the world soils and twice as much as is found in the atmosphere, making it a huge stock of organic carbon locked up in frozen ground.”
“Using geophysical methods like ground penetrating radar and electrical resistance tomography, we can estimate snow thickness, active layer thickness, soil moisture, and permafrost characteristics to better understand Arctic ecosystems.”
“We found that polygon type in ice-wedge polygon landscapes has more explanatory power for variability in properties important for microbial activity and respiration than small polygon features like center or rim.”
“Our genome-enabled reactive transport watershed simulator improved prediction of carbon export to the Colorado River by 200% compared to conventional models.”
“The Upper Colorado River Basin provides water for one in every ten Americans and a lot of hydropower, making it an essential water tower for the world with severe ramifications for the downgradient population.”
“We envision the watershed as a collection of subsystems, each with different responses to perturbations like droughts and floods, which aggregate to yield cumulative outputs of water discharge, carbon, phosphorus, and metal export.”
“Our scale-adaptive modeling approach uses mesh refinement to zoom in and simulate processes where and when they contribute to larger system behavior, allowing us to better predict watershed responses to environmental changes.”
“We have a community observatory approach with multiple teams working together at intensive sites, driven by grand challenge questions, to develop process understanding and inform models for predicting watershed function.”
“We are at a pretty early stage in understanding how terrestrial environments will continue to function throughout this 21st century; will they serve as a carbon sink or will they release carbon? The bottom line is we really just don't know.”
“Permafrost soils store almost as much organic carbon as all soils in the rest of the world combined and more than twice as much as is currently in the atmosphere. The concern is that rapid Arctic warming could release a huge amount of this carbon into the atmosphere.”
“The Arctic is a huge vulnerable land system, similar to the tropics, but while most tropical biomass is above ground, most Arctic carbon is locked below ground, making it a critical tipping point for climate feedbacks.”
“Geophysics provides spatially distributed, minimally invasive data that can be used to understand subsurface systems, but translating geophysical signatures into useful environmental information requires integrating multiple data types and petrophysical relationships.”
“Our conceptual model is that as permafrost degrades, it changes microtopography, which alters water distribution, which in turn affects both above and below ground biology, influencing carbon cycling and ecosystem function.”
September 28, 2016 - Dr. Susan Hubbard, UC Berkeley: "Effects of Climate Change on Watershed Dynamics: Insights from ...
Susan Hubbard is the associate lab director for Earth & Environmental Sciences at Berkeley Laboratory. Dr. Hubbard leads a ...
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