Solar Radiation Management – 2027 Request for Applications

The Simons Foundation supports an international collaborative research program designed to fill fundamental scientific knowledge gaps relevant to solar radiation management (SRM), an emerging collection of approaches, including stratospheric aerosol injection (SAI), marine cloud brightening (MCB) and cirrus cloud thinning (CCT), designed to modify the Earth’s radiative balance and cool the planet. Although reducing atmospheric greenhouse gas concentrations is the only long-term strategy to mitigate climate change and other impacts, SRM might be able to ameliorate some of the negative impacts this century. However, SRM also may pose significant environmental and societal risks, including stratospheric warming, ozone depletion and changes in rainfall, thereby affecting water resources and agriculture. At present, not enough is known about SRM systems and their potential impacts to allow informed decision-making. This call aims to help fill key fundamental knowledge gaps in the science of SRM.

Priority Areas

• Environmentally benign materials discovery for SAI and CCT.
• Laboratory physicochemical characterization of SAI and CCT materials and their interactions with light, clouds, atmospheric trace gases and with themselves or ambient aerosols, with the aim to improve microphysical inputs to existing climate models.
• Approaches to minimize cirrus cloud formation, including from aircraft emissions.
• Assessments of near-field (<100 km) atmospheric turbulence and its impact on SAI and CCT interventions, primarily through modeling.
• Integration of improved representations of aerosols and turbulence into global-scale modeling, and characterization of global and regional impacts of novel materials for SAI and CCT.

Areas not within the scope of this program include social science research and in-situ field experiments involving aerosol release.

Proposals can be from individual investigators or small teams; the latter are not required to be from the same institution but must be organized via a main institution and subcontract institution(s). We will prioritize funding projects which have not been well supported through existing national programs.

Proposals will be judged on scientific quality, potential for impact, potential for collaboration, extent of training graduate students and postdocs, and broadening participation domestically and globally.

As a part of the program obligations, awardees will be invited and expected to attend an annual meeting held at and paid for directly by the Simons Foundation. Grant budgets should not reflect any costs to attend these meetings.

The foundation strongly encourages applications from scientists in the Global South and from investigators who may not have worked in SRM but have expertise that could bring new perspectives and skills to this field. Additionally, this call is also open to active SRM awardees whose current awards are scheduled to end January 2027. All applications will be reviewed competitively for funding to start August 1, 2027.

Personnel

Each proposal should involve not more than three Principal Investigators (PIs): one applicant PI plus up to two investigators in the role of additional PI.

PIs and other project participants may be from U.S. and non-U.S. institutions, with the exception for institutions in China as noted below.

• PIs and co-Investigators on current SRM awards that end January 2027 are eligible to apply to this call.
• PIs and co-Investigators on current SRM awards that end June 2028 are not eligible to apply to this call.
• Note: The role type Co-Investigator will not be used in this call. Please refer to the How to Apply instructions for further details.

Those in an Applicant PI or Additional PI role can be involved in at most two LOIs and two proposals, but can receive support from only one award. If both proposals are selected for funding, it is at the foundation’s discretion as through which award the individual will receive their funding.

Investigators at Universities

PIs must hold a tenured or tenure-track faculty, or equivalent, position at an educational institution in a department with a Ph.D. program at the time of application and for the duration of the award. There are no restrictions on the department and/or discipline of the PIs. Please see the foundation’s grant policies for further information regarding requirements and responsibilities of PIs. Those within non-Ph.D. granting departments are able to participate as funded collaborators or consultants.

Investigators at National Labs or Nonacademic Institutions

PIs must be Ph.D.-level full-time non-visiting research and/or senior scientist or equivalent staff members. Ph.D.-level research staff members may also participate as collaborators or consultants.

Simons Foundation employees who receive a W-2 (Wage and Tax Statement) from the Simons Foundation, including employees of the Flatiron Institute, may not apply as a PI to any Simons Foundation or Simons Foundation International Requests for Applications (RFAs) released by the Simons Foundation. PIs and any project personnel listed on the application who will receive funding for salary, travel, support for students, postdocs or research staff, lab equipment, computing time or other individual expenses may not be employees of the Simons Foundation, which includes the Flatiron Institute.

Eligible Institutions

Applications may be submitted by established U.S. and foreign public and private educational and nonprofit institutes, research centers and national laboratories or the equivalent, with the exception of institutions in China as noted below. Any entity must adhere to the 20 percent maximum overhead rate noted above.

There is no LOI or proposal limit per institution.

Simons Foundation and Simons Foundation International (SFI) do not provide funding to institutions in China (including institutions in Hong Kong), or to fiscal sponsors or agents of institutions in China or Hong Kong. This includes funding to support subcontracts at institutions in China or Hong Kong or consultants residing or working for institutions in China or Hong Kong.

• Award Amount: Up to $1.5 million USD, inclusive of 20 percent indirect costs (see grant policies); annual budgets should be around $500,000 per year, although the foundation would allow the annual budget to vary from $500,000 as long as the total three-year budget is no more than $1.5 million.
• Award Duration: Three years: August 1, 2027 – July 31, 2030
• Number of Awards: The foundation estimates up to 13 SRM awards will be made for awards starting August 1, 2027.

Important Note for Eligible Simons Foundation SRM Current Awardees

The foundation would consider a smaller number of awards for up to $1M per year for three years with more collaborative teams. In these proposals, up to 6 PIs are allowed. We encourage these awardees to do a rigorous evaluation of how well their team is functioning and look for the natural collaborations that have evolved with other project teams. The foundation and the SRM Steering Committee would look favorably on teams that maximize/prioritize restructuring to improve collaboration across projects. We also welcome the addition of new project personnel on currently funded projects. This new collaboration should be made clear in the additional LOI requirement for current awardees.

Increased funding is not guaranteed.

The funding provided may be used to support research expenses in the following categories:

• Universities: Up to one month of summer salary support and related benefits for the collaboration director and each PI/co-Investigator per grant year. Typically, summer salary is solely for 9-month/academic-year faculty to charge research efforts to grants during summer months. For PIs/co-Is with annual appointments (12-month), the program will allow PIs to request up to 1/12 of their annual salary as a contribution to research time, only if an exception exists where their institution permits extra compensation for specific, separate activities outside of regular duties and provided that the summer salary request is not in violation of their institution’s policies of more than 100 percent effort per year. Summer salary funds are not substitutional (cannot be used to relieve a university of salary costs) and cannot be used to reduce teaching loads below the departmental norm. They can only be used to supplement the salary similarly to a summer salary in the U.S. system.
• All other institutions (including national laboratories): For those in PI roles, the grant can provide salary support and related benefits.
• For personnel other than PIs, including staff/research scientists, postdoctoral, graduate and/or undergraduate research assistants, the grant can provide salary support and related benefits, including tuition support.
• Scientific travel for project members per the travel policies of the awardee institution. Parking, hotel, taxi, registration and other related travel and conference costs are allowable.
• Conferences and meetings appropriate to the needs of the project, including meals, travel, lodging, vehicle rentals for participants and facility fees.
• Support for visitors and collaborators, including travel, meals and lodging expenses.
• Equipment, supplies and other research-related expenses, including computers, professional literature, publication expenses and professional membership dues.
• Support for a project administrator.

Expenditures in other expense categories may be possible but must be approved in advance by the foundation.

Please see the Simons Foundation’s grant policies for further guidelines.

Letter of Intent

An LOI must be completed electronically and submitted via the Simons Award Manager (SAM) by October 6, 2026, at 12 p.m. (noon) Eastern time. Please refer to the How to Apply instructions for further details. LOIs will be reviewed by Simons Foundation scientific staff and the SRM steering committee.

Notifications of the status of the LOI will be sent by November 18, 2026.

Full Proposal

A review of the LOI may lead to a request for a full proposal, which will be due by February 17, 2027, at 12 p.m. (noon) Eastern time. Please refer to the How to Apply instructions for further details. Full proposals will be reviewed by Simons Foundation scientific staff, the SRM steering committee, and an expert external review committee.

Award notifications will be sent by July 1, 2027. Awards will begin August 1, 2027.

Please note that in the event of budgetary or other considerations, The Simons Foundation, Inc. (“the Foundation” or “SF”) reserves the right to refer an application to The Simons Foundation International, Ltd. (“SFI”) for consideration and funding. SFI and SF have entered into an agreement pursuant to which SF provides program operations and grant administration services, including payment processing, to SFI. SFI grant recipients are subject to SF Policies and Procedures.

Additional award terms may be included in the official award notification. Grantees are subject to the conditions outlined in their official award notification.

Many of the greatest ideas and discoveries come from a diverse mix of minds, backgrounds and experiences. The Simons Foundation is committed to advancing basic science and mathematics to benefit humankind and expand our collective understanding of our world. As part of our mission, we support partners, programs and initiatives that seek to broaden the scientific community and open pathways to science and mathematics careers.

The Simons Foundation provides equal opportunities to all applicants for funding without regard to race, religion, color, age, sex, pregnancy, national origin, sexual orientation, gender identity, genetic disposition, neurodiversity, disability, veteran status or any other protected category under federal, state and local law.