The Paleo Perspectives on Present and Projected Climate (P4CLIMATE) program, funded by the National Science Foundation (NSF) Directorate for Geosciences, supports interdisciplinary research that provides insights into Earth’s climate system over multi-decadal to millennial timescales. The program addresses limitations of historical records and modern climate models, which often fail to capture long-term climate behavior, tipping points, and thresholds. By utilizing data from geological records and environmental archives, P4CLIMATE seeks to enhance understanding of the climate system's past variability and response to external forcings, providing critical context for predicting future climate conditions.

The program focuses on two primary research themes. The first, *Past Regional and Seasonal Climate*, emphasizes understanding regional climate variability, trends, and extreme events, particularly those impacting hydrological cycles, agriculture, and infrastructure. Research under this theme aims to identify and characterize the drivers of regional and seasonal climate changes, providing insights into climate sensitivity and teleconnections. The second theme, *Past Climate Forcing, Sensitivity, and Feedbacks*, investigates the mechanisms, thresholds, and tipping points that drive climate change, such as cloud radiative feedback, greenhouse gas forcings, and land- and sea-ice dynamics. This theme emphasizes quantifying feedbacks and understanding the state dependence of climate responses.

Proposals are encouraged to employ innovative methodologies, including multiproxy reconstructions, statistical modeling, forward proxy modeling, and robust tools for quantifying uncertainties. Projects should also aim to integrate proxy data with climate models and adhere to FAIR (Findability, Accessibility, Interoperability, and Reusability) data principles to ensure transparency and reproducibility. Additionally, proposers are expected to address societal impacts, promote broadening participation by engaging underrepresented groups and Minority Serving Institutions (MSIs), and consider meaningful stakeholder engagement in research design and dissemination.

The program anticipates awarding approximately 35 new grants annually, with a total funding budget of $14,000,000 per year. Individual projects typically span up to three years, and proposals can be submitted without restrictions on the number of submissions per principal investigator or organization. Proposals must be prepared and submitted via Research.gov or Grants.gov, adhering to the guidelines in the NSF Proposal and Award Policies and Procedures Guide (PAPPG). Fieldwork in Antarctica is not eligible under this solicitation and must instead be submitted to the relevant NSF Office of Polar Programs solicitations.

Proposals will be evaluated based on NSF’s merit review criteria: *Intellectual Merit* and *Broader Impacts.* Reviewers will assess the potential of the research to advance knowledge, benefit society, and achieve measurable outcomes. Projects must also demonstrate alignment with one or both of the program's research themes, incorporate robust data management plans, and articulate clear strategies for outreach, inclusion, and stakeholder engagement.

Successful proposals will demonstrate a commitment to collaborative and multidisciplinary approaches, ensuring data accessibility, fostering inclusivity, and creating broader societal impacts. Researchers are encouraged to engage with program officers early in the proposal preparation process to ensure alignment with P4CLIMATE’s goals. Through this initiative, NSF aims to strengthen our understanding of past climate variability and apply these insights to address pressing questions about Earth’s future climate trajectory.