Iron Salt Aerosols

What is Atmospheric Methane Removal?

Atmospheric Methane Removal is a new climate field researching various approaches to determine how methane, once in the atmosphere, can be broken down faster than with existing natural systems alone. New approaches in this category would shorten methane’s atmospheric lifetime, and could help lower peak temperatures and counteract some of the impact of large-scale natural systems methane releases. Research into Atmospheric Methane Removal is at an early stage, and could be an addition to, never a replacement for, aggressive emission reductions for all greenhouse gases.

What are Iron Salt Aerosols?

Iron Salt Aerosols (ISA) is one potential approach to Atmospheric Methane Removal. ISA might prove to be a highly- and rapidly-scalable approach, however fundamental research questions are unanswered regarding potential climate benefit and unintended consequences.

Methane lasts in the atmosphere for about a decade because it’s broken down via oxidation (a chemical or biological process) into carbon dioxide and water. Methane is primarily broken down through chemical reactions in the atmosphere with hydroxyl and chlorine radicals..

Saharan dust plumes are a natural phenomenon that scientists believe are contributing to the breakdown of methane. The proposed ISA approach takes inspiration from this phenomena, and involves lofting iron-based particles into the atmosphere above remote marine environments, where they mix with sea salt spray, to trigger atmospheric processes that generate short-lived chlorine radicals, which can accelerate the breakdown of methane in the atmosphere in some conditions.

Under the right conditions, lofting ISA into the atmosphere could potentially reduce atmospheric methane concentrations and lower global surface temperatures, however much more research is needed to understand its full climate impacts and potential unintended consequences.

Learn More about the State of the Science

Spark's Work on ISA

Spark is supporting robust scientific research to assess the viability and full potential impacts of ISA as a potential methane removal approach, alongside supporting other atmospheric methane research areas and emissions reduction approaches.

As atmospheric methane concentrations rise, the highest priority is anthropogenic emission reductions, both through deploying existing solutions and innovating new ones. There is also an immediate need to explore atmospheric methane removal approaches in parallel, as they may be a crucial climate response to rising natural methane emissions, which are anthropogenically amplified and not easily controlled. Spark is committed to exploring a diverse set of potential atmospheric methane removal approaches, not limited to ISA, as parallel research will be necessary to advance climate responses on the necessary timescale.

Current Research Grantees

Led by a team of researchers from University of Copenhagen, Cornell University, Utrecht University, and the Spanish National Research Council, with support from OceansX and Acacia Impact Innovation , the Spark-funded consortium conducts modeling, laboratory, and field measurements to explore the natural analogue of ISA and advance the understanding of ISA as a potential atmospheric methane removal approach.

Led by researchers from Stony Brook University, in collaboration with Utrecht University, University of Copenhagen, Acacia Impact Innovation, University of Miami, Purdue University, and the Spanish National Research Council, the Spark-funded effort will advance understanding of the naturally occurring iron salt aerosol mechanism in the North Atlantic through an aircraft field campaign in Barbados in 2024. This work will occur alongside complementary aircraft and ground-based investigations funded by the National Science Foundation, US Navy, and NOAA, with opportunities to leverage research capabilities through data and resource sharing.

Guiding Principles

Spark is committed to building and fostering a community of researchers and partners who work collaboratively to limit warming, manage Earth systems risk, and help enable our return to a safe climate. A science-based approach, informed and in tandem with understanding of community and environmental impact, is core to our mission. We are approach agnostic—while recognizing the necessity to explore many potential approaches in parallel—and driven by a need to identify and mitigate sources of unmanaged climate risk.