Today, public concern about the environment, climate change and limited fossil fuel resources are important drivers for governments, companies and scientists to find alternatives to crude oil. Bio-based plastics may offer important contributions by reducing the dependence on fossil fuels and the related environmental impacts. In the past few decades, many new polymers from renewable feedstocks were developed. For example, starch, i.e. a naturally occurring polymer, was rediscovered as plastic material. Other examples are PLA that can be produced via lactic acid from fermentable sugar and PHAs which can be produced from vegetable oil next to other bio-based feedstocks. Recent developments in emerging bio-based plastics are spectacular from a technological point of view. Many old processes have been revisited, such as the chemical dehydration of ethanol which leads to ethylene, an important intermediate chemical which can be subsequently converted into polyethylene (PE), polyvinyl chloride (PVC) and other plastics. Moreover, recent technology breakthroughs substantially improved the properties of novel bio-based plastics, such as heat-resistance of PLA, enabling a much wider range of applications. For numerous types of plastics, first-of-its kind industrial plants were recently set up and the optimization of these plants is ongoing. Some of the plant capacities are still rather small when compared to petrochemical plants (capacity of Tianan’s PHA plant is only 2 kt), but others are very sizeable (Dow-Crystalsev’s biobased PE plant is to have capacity of 350,000 tons). With growing demand for bio-based plastics, it is probably just a matter of time until turnkey plants with large capacities will be commercially available for more bio-based plastics, thereby allowing substantially accelerated growth. This study estimates the global capacity of emerging bio-based plastics at 0.36 mln tons by the end of 2007. This is approximately 0.3% of the worldwide production of all plastics (dominated by petrochemical plastics). The current production capacity of bio-based plastics is even smaller compared to “conventional bioproducts”: they represent only 2% of the global production of established bio-polymers (20 tons; comprising cellulose polymers, alkyd resins and non-food starch without starch for fuel ethanol) and only 0.1% of the world paper and board production. However, the market of emerging bio-based plastics has been experiencing rapid growth. From 2003 to end of 2007, the global average annual growth rate was 38%. In Europe, the annual growth rate was as high as 48% in the same period. The total maximum technical substitution potential of bio-based polymers replacing their petrochemical counterparts is estimated at 270 tons, or 90% of the total polymers (including fibres) that were consumed in 2007 worldwide. It will not be possible to exploit this technical substitution potential in the short to medium term. The main reasons are economic barriers (especially production costs and capital availability), technical challenges in scale-up, the short-term availability of bio-based feedstocks and the need for the plastics conversion sector to adapt to the new plastics. Nevertheless, this exercise shows that, from a technical point of view, there are very large opportunities for the replacement of petrochemical by bio-based plastics. The worldwide capacity of bio-based plastics, according to company announcements, will increase from 0.36 tons in 2007 to 2.33 tons in 2013 and to 3.45 tons in 2020. This is equivalent to average annual growth rates of 37% between 2007 and 2013 and 6% between 2013 and 2020. In 2007, the most important products in terms of production volumes were starch plastics (0.15 tons) and PLA (0.15 tons). Based on the company announcements it is projected that the most important representatives by 2020 will be starch plastics (1.3 tons), PLA (0.8 tons), bio-based PE (0.6 tons) and PHA (0.4 tons). Today, the combined volume of these non-food and non plastics applications of starch and man-made cellulose fibres is 55 times larger than the total of all new bio-based polymers (approx. 20 tons versus approx. 0.35 tons in 2007). The new bio-based polymers may reach this level in 20-30 years from now. The use of starch for paper production only amounts to 2.6 tons and is hence still six times larger than today’s worldwide production of bio-based plastics. This demonstrates that the production of bio-based products at very large scale is not unprecedented. First-in-kind production of bio-based plastics in large industrial plants should be seen as a large-scale experimental phase in which the strengths and weaknesses of the various biobased plastics and their production routes become apparent. The experience gained must then be taken into account when the production reaches the steep phase of the S-curve. It will hence take more than two decades from now until meaningful benefits such as CO2 emission reduction will be achieved at the macro level. On the other hand, the advantages of slow substitution of petrochemical plastics are that technological lock-in can be more easily avoided and that an optimized portfolio of processes can be implemented, ensuring maximum environmental benefits at lowest possible costs and minimum social backlash. Several factors clearly speak for bio-based plastics. These are: the limited and therefore uncertain supply with fossil fuels (especially oil and gas), the related economic aspects, environmental considerations (especially savings of non-renewable energy and greenhouse gas abatement), innovation offering new opportunities (technical, employment etc.) and rejuvenation in all steps from chemical research to the final product and waste management. Challenges that need to be successfully addressed in the next years and decades are the lower material performance of some bio-based polymers, their relatively high cost for production and processing and the need to minimize agricultural land use and forests, thereby also avoiding competition with food production and adverse effects on biodiversity and other environmental impacts. Based on a report commissioned by European Polysaccharide Network of Excellence (EPNOE) and European Bioplastics