The new materials development is now transitioning between the petroleum based hydrocarbon chemistry and the biomass derived carbohydrate chemistry. Renewable resource based bioplastics like cellulosic plastics; polylactic acid (PLA); polyhydroxybutyrate (PHB); and soybean based plastics etc. need value-added applications to compete with the fossil fuel derived plastics. This presentation will give an overview of various renewable resource based green/bio-plastics and their sustainable developments through blends, composites and nanocomposites with a deep insight in to cellulose ester-layered silicate based 'green' nanocomposites. Nano reinforcements of biobased polymers are poised to create the next generation of value-added novel eco-friendly nanocomposites in greening the 21st century materials world. The developing biobased nanocomposites need to be sustainable to compete with the existing petroleum-based nanocomposites for applications in greener automotive parts, packaging and consumer goods. Green nanocomposites have been successfully fabricated from renewable resource based cellulose acetate (CA) bioplastic, eco-friendly triethyl citrate (TEC) plasticizer and organically modified clay through extrusion followed by injection molding processing. The processing conditions, such as mixing methods, pre-plasticizing times, retention times (RT), as well as the use of maleic anhydride grafted cellulose acetate butyrate (CAB-g-MA) compatibilizer affected the performance of these new developing nanocomposites. The morphologies of the nanocomposites were evaluated through X-ray diffraction (XRD), atomic force microscope (AFM), and transmission electron microscopy (TEM) studies. Cellulosic plastic-based nanocomposites obtained using increased pre-plasticizing times and RT showed better-exfoliated structures. Cellulosic plastic-based nanocomposites with 5 wt. % compatibilizer contents showed better exfoliated structure than the counterpart having 0 or 7.5 wt. % compatibilizer contents. Polygonal shape of exfoliated clay platelets was observed with 500 nm width, and 800 nm length by AFM and TEM imaging. The mechanical properties of these nanocomposites have been correlated with the XRD, TEM and AFM observations. The sustainability issues of cellulose ester based green nanocomposites are analyzed and discussed as compared to polypropylene-clay nanocomposites on the basis of their cost-performance and environmental impacts.