The worldwide production of plastics reached 260 billion lbs/yr. at the end of the 20^th century, with a value of over $300 billion to US economy. We need plastics, but the pain American consumers are feeling at the gas pump is also sharply impacting the plastics industries.  What will happen to our environment, to human and animal health, and to the plastics industries – the fourth largest manufacturing sector of the U.S. economy – if sustainable technologies are not developed and deployed?  A promising strategy that is consistent with the principles of Green Chemistry and Engineering is the use of renewable resources to make plastics.  Efforts to date using renewable resources have not met all technical and economic targets.  However, new nanocomposites based on renewable resources now show great promise.  Ecologically responsible conversion of renewable resources through industrial biotechnology, enhanced by nanotechnology, produces green materials that represent a triple technological convergence. This convergence is resulting in a class of bioplastics that can be referred to as Ecobionanocomposites.  Progress towards petroleum-free, sustainable plastics has been accomplished by developing new polylactide-graft-cellulose nanowhisker supramolecular structures.  Preliminary results show that these novel structures that bridge the length scales between traditional copolymers and conventional microcomposites do indeed have superior thermophysical properties.