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
What causes global warming? The cause of global warming is the increasing quantity of greenhouse gases in the our atmosphere produced by human activities, like the burning of fossil fuels or deforestation.