Topic: Limestone

A geologist explains that the Earth has been "degassing" carbon dioxide for over 4.5 billion years and that current levels (0.04%) are dangerously low. He argues that CO2 is essential "plant food" rather than a pollutant, noting that halving the current amount would kill all terrestrial plants. The speaker points out that historical sea level changes have been as large as 1,500 meters, far exceeding modern variations.

The hosts examine media reports and statements from Barack Obama and Al Gore regarding fish swimming in the streets of Miami Beach. They clarify that the flooding is often caused by water seeping up through porous limestone rather than sea-level rise alone. Curry highlights Gore's careful phrasing about "sea level predictions" rather than actual measured rises in sea level.

A BBC report claims that Miami Beach is becoming a "modern-day Atlantis" due to rising sea levels. The report specifically targets President Trump's Mar-a-Lago estate, predicting a quarter of the property will be underwater in decades. The hosts point out that Miami's flooding is often caused by water seeping through porous limestone rather than simple sea-level rise.

A listener provides a correction regarding the construction of houses in Bermuda. The white rooftops are made of "Bermuda stone," which is a porous coral-based limestone. The stone acts as a filter for rainwater, which is then collected in large underground cisterns, a primary source of fresh water on the islands.