Researchers use pattern matching (aka skeleton plotting) and statistical analysis to assign years to each ring, called cross-dating. If the rings tell a similar story, the researchers can more confidently estimate meteorological records back to years before weather instruments existed. Photo by Nicole Davi
Tags:
COP31, the 2026 United Nations Climate Change Conference, aims to advance dialogue, strengthen consensus, and accelerate climate action on a global scale. From November 9–20, 2026 in Antalya, Türkiye, heads of state, ministers, scientists, business leaders, and civil society will gather to advance efforts in emission targets, climate finance, and adaptation and resilience. Once again, our experts, students, and global thought leaders from Columbia Climate School and across Columbia University are contributing to key events, sharing insights, and helping shape the dialogue toward ambitious, science-based solutions. Learn More