Moderated by Usha Lee McFarling, Pulitzer Prize-Winning Science Journalist Scientists have demonstrated that climate change is real, but polls show that 30 percent of Americans disagree. Scientists have shown that genetically modified foods pose no threat, but, according to one survey, half the country sees such foods as dangerous. And despite scientific assurances about vaccine safety, the number of very young children who don’t get vaccinated has quadrupled in the past two decades. Why are so many Americans ignoring—or rejecting—broad scientific…