Physicist challenges conventional wisdom of climate change impact

U.S. companies are spending billions to reduce their carbon footprints. Steven Koonin, a physicist and former undersecretary for science in the Obama administration, is challenging the conventional wisdom on climate science and its impact on business and the U.S. economy. Koonin joined "Squawk Box" on Tuesday to discuss his new book "Unsettled: What Climate Science Tells Us, What it Doesn't and Why it Matters."