Squawk Box

Most people are probably not familiar with Joe Kernen, a morning anchor for the financial network CNBC. On Tuesday, he invited singer Sheryl Crow and “An Inconvenient Truth” schlockumentary producer Laurie David on to discuss their “Stop Global Warming College Tour.”As Kernen tried to present the skeptics’ side of this debate, the ladies clearly got uncomfortable and, to say the least, a bit…