Dear readers,

The Second Latin-American Radiocarbon Conference (CLARa2) took place from September 4–8, 2023, in Mexico City, Mexico, as part of the celebration of the ten-year anniversary of the National Laboratory of Accelerator Mass Spectrometry (LEMA) of the Institute of Physics at UNAM. The Conference was held at the Templo Mayor Museum with an attendance of about 110 participants from 13 countries.

The Latin American community dedicated to radiocarbon dating has entered a phase of expansion and maturity, driven by new AMS capabilities, the emergence of laboratories, and—above all—the creation of networks that raise standards of quality and collaboration. At the initiative of LACUFF, under the leadership of its director, Kita Macario, the first Latin American Radiocarbon Conference (CLARa1) was held in Niteroi, Rio de Janeiro, Brazil, from July 29 to August 2, 2019. The objective was to convene, for the first time, researchers from Latin America and representatives of the global radiocarbon community. This decision was a step toward rewriting colonial narratives and positioning Latin America as an indispensable actor in global scientific discussions. Our main objective is to foster a sense of belonging within this regional community, so that we can grow together, enhancing our protagonism, especially when dealing with climate changes and the preservation of our cultural and natural heritage.

CLARa2 confirms the consolidation of this network of laboratories, groups, and early-career researchers that, across diverse institutional contexts, share common standards, challenges, and scientific ambitions. This special issue of Radiocarbon brings together a selection of contributions that reflect this dynamism and, at the same time, demonstrate the breadth of topics in which ¹⁴C—measured either by accelerator mass spectrometry (AMS) or by scintillation spectrometry—is crucial for addressing questions not only in archaeology, one of the traditional pillars of dating in Latin America, but also in climate change, geosciences, forensics, and AMS methodology itself.

The CLARa2 program consisted of 38 invited talks and a lively poster session with 31 posters covering a large variety of topics in radiocarbon history, including the local perspective of Latin America, radiocarbon dating and pre-Columbian America, hydrology, ocean and reservoir effects, tools and modeling, climate and paleoclimate studies, radiocarbon and environment, earliest human occupations in America, technical aspects about radiocarbon and AMS, AMS and other cosmogenic applications, and one workshop on calibration and modeling of dates using R.

The works compiled here demonstrate advances in pretreatment and quality control, as well as in quantifying and correcting reservoir effects in both marine and continental contexts. Several articles address challenges characteristic of the region—preservation in tropical environments, volcanic influence, complex mixtures of carbon sources, discontinuous chronologies—proposing robust and transparent methodological solutions. Others contribute to high-resolution chronologies for archaeological and palaeoecological sequences, validation of dates through multiproxy approaches, and emerging applications, including the construction and use of archaeometric databases in Latin America.

A constant throughout the contributions is the adoption of best practices: sample traceability, comprehensive reporting of pretreatments, explicit calibration and Bayesian modeling, and data availability. Likewise, there is a clear regional commitment to capacity building and expansion: modernization of facilities, creation of reference collections, and strengthening of intra- and intercontinental partnerships that facilitate access to infrastructure, knowledge transfer, and independent evaluation.

CLARa2 has not only been a forum to present results; it has, above all, been an exercise in community-building. The diversity of sites, periods, and problems addressed coexists with a shared ethic of metrological rigor and openness. We hope this special issue will help make visible the work of a growing collective and serve as a meeting point for future collaborations that deepen—through the power of ¹⁴C—our understanding of the past, present and future of Latin America. We thank the authors for their submissions, the reviewers for their diligent assessments, and the institutions that, within the region and beyond, sustain this shared scientific endeavor.

We look forward to seeing everyone at CLARa3 in 2026 (July 8–10). The meeting will be combined with Radiocarbon and Diet IV (July 6–8) and held at the Catholic University of Chile (Pontificia Universidad Católica) in Santiago. The conference organizers are Kita Macario and Francisca Santana Sagredo (14cdiet.clara3@gmail.com).

Corina Solís Rosales & Kita Macario

Guest Editors

Conference photos

Conference participants at Mexico City Zócalo.

Conference registration desk.

Fun at LEMA.

Poster Session 1.

Poster Session 2.

Participants at Templo Mayor.

Tour of Templo Mayor Museum.

Lunch at the cave restaurant La Gruta.

Conference group at Teotihuacán.

Night view of the conference dinner.