Blood group: An inherited feature on the surface of the red blood cells. A series of related blood types constitutes a blood group system, such as the Rh or ABO system. The frequencies of the ABO and Rh blood types vary from population to population.lood group: An inherited feature on the surface of the red blood cells. A series of related blood types constitutes a blood group system, such as the Rh or ABO system. The frequencies of the ABO and Rh blood types vary from population to population.
October 22, 2009. Running time 1:26. Climate scientists explain why theyâre sure the primary cause of global climate change today is increasing human emission of greenhouse gases â mainly carbon dioxide. Skip to main content
Yet back home, President Obama still faces an electorate that doesnât believe climate change is caused by humans. Only 40% of Americans attribute global warming to human activity, according to a recent Pew Research Center poll. This, despite decades of scientific evidence and the fact that Americans generally trust climate scientists. Despite decades of evidence, most Americans don't believe that humans are causing climate change. That apparent cognitive dissonance has vexed two scientists in particular: Michael Ranney, a professor of education at the University of California, Berkeley, and Dan Kahan, a professor of law at Yale University.