Technical Abstract: Although the impact of rising atmospheric carbon dioxide on temperature increases and climate have been the focus of much scientific inquiry, the direct impact of rising carbon dioxide on plant biology has been largely ignored. In this review, research related to the direct effect of rising CO2 on both managed and unmanaged plant systems is presented using a number of pragmatic examples of the type of consequences (both positive and negative) that may, or are, occuring. It is clear that increasing carbon dioxide of and by itself will significantly impact both plant and human systems in ways that are largely ignored. Some of these impacts are related to food security, nutrition value, spread of weedy and invasive species and human health. However, there remain a diverse multitude of other likely CO2-induced impacts that need to be addressed. These include, but are not limited to changes in: species diversity, insect pollination, human nutrition, plant-derived narcotics, plant toxicology, plant pathology, etc. It is regrettable that in the debate regarding rising CO2 and global warming, that the direct impact of rising carbon dioxide on plant biology, and the role of plants in sustaining life, remains under-appreciated by all sides.