Although the results of Dr. Idso's research need to be studied further, it is intriguing to speculate about the implications of plants growing larger and becoming more environmentally efficient as carbon dioxide levels increase. Could it be that during the pre-flood time, not only was there a water-vapor canopy and a tropical environment, there also were significantly increased carbon dioxide levels than what is contained in the earth's atmosphere today?[14] If this were the case, then there might have been much greater vegetation than we have today. With increased vegetation, there would have been a great need for large plant-eating animals such as dinosaurs to control vegetation levels. In addition, the large vegetation levels could have provided more than adequate material for the production of great quantities of fossil fuels during Noah's Flood.