A key report to President Lyndon B. Johnson in 1965 warned that humankind was "unwittingly conducting a vast geophysical experiment" through the burning of fossil fuels and a consequent buildup of "the invisible pollutant" — carbon dioxide — in the atmosphere. Here's the story of what happened next to that report — and what didn't, and why.

Host Adam Levy speaks with Harvard science historian Naomi Oreskes, coauthor of the book Merchants of Doubt: How a Handful of Scientists Obscured the Truth on Issues from Tobacco Smoke to Global Warming. And he talks with environmental scientist Dana Nuccitelli, research coordinator for Citizens' Climate Lobby, which aims to build political will for climate solutions through citizen volunteers.

Find the transcript and additional resources at knowablemagazine.org/podcast