Problem Statement Repository

Surfacing actionable problems

Communicating problems and supporting solutions

The Problem Statement Repository is a curated set of community-generated problem statements designed to connect big challenges to actionable goals.

We support solutions. Problem statements with the Greenhouse Gas Removal tag can be used in applications to Garden Grants: GHGR, which will accept proposals until Feb. 28.

Greenhouse gas removal Methane

2/20/25

Measure environmental growth rates of atmospheric methane oxidizing bacteria

To understand the potential of soil and trees for methane mitigation, we need to know the environmental growth rates of atmospheric methane oxidizing bacteria and the factors that influence it.

by Alexander Tøsdal Tveit, Pok Man (Bob) Leung, Marc Dumont, Hendrik Schaefer, Rachel Strickman, and Paul Reginato

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Greenhouse gas removal Methane

2/12/2025

Estimate atmospheric methane removal potential of engineered plants expressing MMO

Atmospheric methane oxidation by MMO-expressing plants is a compelling idea that requires further theoretical exploration.

by Paul Reginato, Eli Hornstein, and Verena Kriechbaumer

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Greenhouse gas removal Methane

2/11/2025

Lab validation and characterization of atmospheric methane uptake by microbes in the phyllosphere

Identifying the microbial mechanism of atmospheric methane uptake in trees may reveal levers for methane mitigation.

by Alexander Tøsdal Tveit, Pok Man (Bob) Leung, Hinsby Cadillo-Quiroz, Luke Jeffrey, Rachel Strickman, and Paul Reginato

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Greenhouse gas removal Methane

2/11/2025

Measure the heritability of methane flux in plantation trees and crops

If methane flux is a heritable trait in plants, then breeding could be a methane mitigation strategy.

by Steven Strauss, Jean-Francois Lamarque, Mari Pihlatie, Rachel Strickman, and Paul Reginato

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Greenhouse gas removal Methane

2/11/2025

Standardize protocols and instrumentation for measuring methane flux in trees

Intercomparable measurements are needed to build actionable models of forest methane flux.

by Mari Pihlatie, Steven Strauss, Jean-Francois Lamarque, Hinsby Cadillo-Quiroz, Luke Jeffrey, Rachel Strickman, and Paul Reginato

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Greenhouse gas removal Methane

2/11/2025

Mechanistic study of tree methane flux hotspots globally

Multifactor measurements and controlled experiments on tree methane flux are needed to produce models that will guide interventions for emissions minimization and atmospheric methane removal.

by Mari Pihlatie, Steven Strauss, Jean-Francois Lamarque, Luke Jeffrey, Rachel Strickman, and Paul Reginato

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Greenhouse gas removal Methane

02/06/2025

Survey tree methane flux across biomes globally

Tree methane fluxes must be systematically measured across biomes to enable integration of trees into global models and identify methane uptake hotspots that may hold clues to uptake enhancement strategies.

by Jean-Francois Lamarque, Mari Pihlatie, Steven Strauss, Hinsby Cadillo-Quiroz, Luke Jeffrey, Rachel Strickman, and Paul Reginato

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Greenhouse gas removal Methane

01/29/2025

Develop a sensitive and high-throughput assay for methane oxidation

A novel assay for methane oxidation is needed to enable engineering and heterologous expression of MMO variants for methane mitigation technologies.

by Amy Rosenzweig, Eli Hornstein, Arjun Khakar, Verena Kriechbaumer, Jonas Wilhelm, Rachel Strickman, and Paul Reginato

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Greenhouse gas removal Methane Protein engineering

01/27/2025

Design a de novo methane monooxygenase

A novel MMO that is active and readily expressible across hosts would enable methane mitigation technologies.

by Eli Hornstein, Arjun Khakar, Verena Kriechbaumer, Amy Rosenzweig, Jonas Wilhelm, Rachel Strickman, and Paul Reginato

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Greenhouse gas removal Methane

01/25/2025

Optical biosensors and lipidomics for biophysical characterization of pMMO function

The conditions necessary for native pMMO function must be understood to enable heterologous expression for methane mitigation technologies.

by Amy Rosenzweig, Verena Kriechbaumer, Eli Hornstein, Arjun Khakar, Jonas Wilhelm, Rachel Strickman, Paul Reginato

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Greenhouse gas removal Enhanced weathering Geobiotechnology

09/27/24

Functionally characterize microbial weathering processes in soil

Functional characterization of microbial weathering in soil is needed to develop bio-ERW methods.

by Paul Reginato, Pritha Ghosh, Petra Pjevac, Derek Bell

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Greenhouse gas removal Enhanced weathering Geobiotechnology

09/27/24

Platforms for high-throughput characterization of biologically-enhanced mineral weathering

Platforms are needed to enable rapid characterization of biological weathering for bio-ERW method development.

by Paul Reginato, Pritha Ghosh, Buz Barstow, Esteban Gazel

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Greenhouse gas removal Enhanced weathering Geobiotechnology

09/27/24

Systematic lab characterization of microbially-enhanced mineral weathering

Microbial weathering mechanisms should be systematically characterized to enable bio-ERW method development.

by Paul Reginato, Pritha Ghosh, Buz Barstow, Esteban Gazel

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Greenhouse gas removal Enhanced weathering Geobiotechnology

07/31/24

Propose and assess microbial community functions for reactor-based bio-enhanced weathering

Microbial community functions should be proposed that could underlie reactor-based bio-ERW, to guide engineering and design.

by Paul Reginato, Pritha Ghosh, Nathan G. Walworth, and Martin Van Den Berghe

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Greenhouse gas removal Enhanced weathering Geobiotechnology

07/31/24

Design, TEA, and LCA of reactor-based bio-enhanced rock weathering

Designs should be proposed and analyzed for reactor-based bio-ERW to assess feasibility and guide engineering.

by Paul Reginato, Pritha Ghosh, Nathan G. Walworth, and Martin Van Den Berghe

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Protein engineering Methane Greenhouse gas removal

04/06/24

Cell-free methane oxidation without reductant input

A cell-free system should be developed to oxidize methane without the input of additional small-molecule reductants or cofactors.

by Paul Reginato, Chris Eiben, James Weltz, and Paige Brocidiacono

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Methane Greenhouse gas removal

04/06/24

Design and modeling of dilute methane oxidation bioreactors to guide bioengineering

Possible designs for bioreactors that oxidize dilute methane for warming mitigation must be proposed and analyzed to assess feasibility and provide guidance for engineering

by Paul Reginato, Mary Lidstrom, Jeremy Semrau, Jessica Swanson, Lisa Stein, Wenyu Gu, Mark Hansen, Paige Brocidiacono, Ariana Caiati, and Erin Wilson

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Protein engineering Methane Greenhouse gas removal

03/10/24

Genetic tools for particulate methane monooxygenase

Methods must be developed to enable study and engineering of pMMO, the most ubiquitous methane-oxidizing enzyme.

by Paul Reginato, Calvin Henard, Mary Lidstrom, Jeremy Semrau, Jessica Swanson, Wenyu Gu, Lisa Stein, James Weltz, Mark Hansen, Paige Brocidiacono, Ariana Caiati, and Erin Wilson

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Protein Engineering Methane Greenhouse gas removal

03/10/24

Discover or engineer efficient soluble methane monooxygenase

sMMO is the most tractable methane-oxidizing enzyme, and we should be engineering it to mitigate atmospheric methane and area emissions.

by Paul Reginato, Lisa Stein, Mary Lidstrom, Jeremy Semrau, Jessica Swanson, Wenyu Gu, Noah Helman, James Weltz, Mark Hansen, Paige Brocidiocono, Ariana Caiati, and Erin Wilson

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Protein engineering Bioplastics

12/01/23

Assay for monomer incorporation by polyester synthase to enable bioplastics engineering

Develop an assay to enable enzyme engineering for improved bioplastics that reduce the need for fossil fuels.

by Nils Averesch, Paul Reginato

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Protein engineering Bioplastics

12/01/23

Polyester synthase for novel bioplastics with tunable properties

Enzyme engineering to synthesize improved bioplastics that reduce the need for fossil fuels.

by Nils Averesch, Paul Reginato, and Ariana Caiati

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Protein engineering Agriculture

11/15/23

De novo nitrogenase to facilitate engineered nitrogen fixation in plants

Reduce fertilizer emissions by engineering plants to self-fix nitrogen.

by Steven Singer, Paul Reginato, and Ariana Caiati

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Protein engineering

11/15/23

Lower the Km of carbonic anhydrase

Engineer enzymes to boost CO2 absorption rates for enhanced carbon capture efficiency.

by Paul Reginato, Sonja Salmon, and Ariana Caiati

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Protein engineering

08/22/23

Develop ultrastable carbonic anhydrase for DAC and PSC

Engineer a more stable enzyme to reduce costs and energy use in direct air and point-source CO2 removal processes.

by Paul Reginato

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Protein engineering

08/22/23

Assay for CO2 mass transfer rates in small solvent volumes to enable enzyme-enhanced DAC and PSC

Develop a novel method to measure CO2 exchange rates in small solvent volumes to enable breakthroughs in enzyme-enhanced DAC and point-source capture.

by Paul Reginato

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Protein engineering

08/22/23

Techno-economic analysis to guide development of bio-enhanced DAC

Techno-economic analysis to pinpoint the optimal integration of carbonic anhydrase in DAC technology.

by Paul Reginato

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Problem Statement Repository Surfacing actionable problems

Problem Statement Repository Surfacing actionable problems

Communicating problems and supporting solutions

Problem Statement Repository

Surfacing actionable problems

Problem Statement Repository

Surfacing actionable problems