Depletion of fossil resources, global warming, and increasing world's population represent major Damocles' sword for humanity to ensure its future against famine, climate change, and the end of the petroleum era. Solutions will come from production of plant-based chemicals, which is not new, nor a historical artifact. On earth, 99% of the biomass alive is composed of plants and microorganisms. Because of this biodiversity, it could be sufficient as a comprehensive sustainable resource of reagents for industry. Against this background, what will be needed for the industry worldwide to solve the long-standing unresolved problem of how to convert plant biomass into reagents, ingredients, and products with acceptable societal, environmental, and cost levels? There is an urgent need for conceptual leap in fundamental and applied research by original 'multi-scales understanding.' Mitigating climate change fueled by anthropogenic activities with plant-based green chemistry to establish a circular bio-based economy while adhering to the Sustainable Development Goals is the scope of this perspective review.