NOVA: Holdren, Schrag Explain Climate Change

In 1824, Joseph Fourier, who was once science advisor to Napoleon Bonaparte, deduced that the composition of the atmosphere governs the earth’s surface temperature. Climate science has been progressing ever since, according to John P. Holdren, Science Advisor to former President Barack Obama and Co-Director of the Belfer Center’s Science, Technology, and Public Policy Program.

In a new PBS NOVA documentary, Decoding the Weather Machine, Holdren notes that climate science—accumulating since Fourier’s time—proves that humans are responsible for the big increases in heat-trapping gases in the atmosphere. 

“We are seeing one-in-a-thousand-year floods with astonishing frequency,” Holdren says in the two-hour special in which he and STPP Co-Director Dan Schrag share their expertise on science and climate issues. We will also likely continue to see more Category 4 and 5 hurricanes, he adds, and devastating heatwaves will be much more extreme. 

We know that “carbon dioxide is a major driver of climate,” Schrag says, and study of the oceans has contributed to that knowledge. The floor of the ocean is essentially a tape recorder, Schrag explains. “We can take those fossil shells, measure their chemistry and reconstruct what the temperature of that ancient seawater was so long ago.”

To reduce suffering, we need to maximize mitigation and adaptation now, Holdren says. “The largest uncertainty about climate change is what we decide to do.”