May 13, 2007: Climate Change and Global Warming - Richard Somerville
The conversation addresses specific projections, including a NASA study suggesting eastern U.S. summer temperatures could rise nearly ten degrees Fahrenheit by the 2080s, with cities like Chicago, Washington, and Atlanta potentially averaging between 100 and 110 degrees during dry spells. Somerville discusses the international dimension of the crisis, noting that China is poised to surpass the United States in carbon emissions and opens a new coal-fired power plant every few days.
Art presses Somerville on practical solutions and political obstacles, including the influence of industry-funded skepticism that mirrors tactics once used by the tobacco lobby. They discuss the so-called BRIC nations, the challenge of balancing economic development with environmental responsibility, and why Somerville believes the scientific consensus on human-caused warming is as strong as the link between smoking and lung cancer.
Key Moments
Settled Science and the Fingerprint of Humanity: Somerville, an IPCC coordinating lead author, explains that 30 years of satellite and modeling progress has produced a real consensus: melting glaciers, shrinking sea ice, rising temperatures, and changing precipitation match what scientists had predicted - the human fingerprint on climate is now beyond reasonable doubt.
Tipping Points and the Light Switch: Somerville responds to a Guardian story on a possible carbon-cycle tipping point. He explains tipping points probabilistically: Greenland could destabilize Tuesday morning or in 500 years. The climate system can behave like a light switch - push, push, push, then flip.
Why Skeptics Are Really Angry: When Art notes the audience's anger at climate science, Somerville argues the resistance isn't really about the science - it's about feared consequences: taxes, fuel mandates, government interference. People in denial because they don't want to believe what the policy implications would be.
Greenland, Ice Quakes, and 20 Feet of Sea Rise: Somerville details the Greenland ice sheet risk: 20 feet of global sea level rise if it fully melted, with monitoring teams now hearing 'ice quakes' as melt water lubricates the bedrock interface and accelerates calving - mechanisms the IPCC tiptoed around because the science wasn't yet settled.
The Arctic Albedo Feedback: Somerville explains why the Arctic is warming fastest: as snow and ice melt, the dark surface beneath absorbs sunlight that the white surface reflected. He compares it to walking barefoot on a black road versus a white sidewalk - a self-amplifying feedback loop.