There is debate going on under the carpet why not we go ahead with nuclear fuel energy instead of biofuel energy. Its obvious that our energy needs are growing and one of the option is nuclear energy. I am not proponant of nuclear energy. However all things have to be weighed in present context future requirements. I can only talk about plants . Plants are the only source to provide the natural oxygen or recycle carbondioxide to produce oxygen again . No other mechanism can provide oxygen as far as I know. What will happen if there is excess of carbondioxide and green house effect and global warming and conditions become inhospitable for the survival. What will happen if all the vegetation is cut and burn in proper and improper manner to provide fuel for millions and millions of poor people with no forests remaining. In case no forests are there where will the oxygen come from. Choice is getting narrower and narrower. However can there be substitute for plants. Can our plantet survive without oxygen or can it survive without energy also. You decide.