Lonnie Thompson discusses clues to Earth's ancient climate history that are stored in tropical glacial ice.

Biocontainment safeguards

Welcome to Science Sessions, the PNAS podcast program. Listen to brief conversations with cutting-edge researchers, Academy members, and policymakers as they discuss topics relevant to today's scientific community. Learn the behind-the-scenes story of work published in PNAS, plus a broad range of scientific news about discoveries that affect the world around us.