• Energy Research

AbstractRising atmospheric carbon dioxide concentration ([CO2]) significantly influences plant growth, development, and biomass. Increased photosynthesis rate, together with lower stomatal conductance, has been identified as the key factors that stimulate plant growth at elevated [CO2] (e[CO2]). However, variations in photosynthesis and stomatal conductance alone cannot fully explain the dynamic changes in plant growth. Stimulation of photosynthesis at e[CO2] is always associated with post‐photosynthetic secondary metabolic processes that include carbon and nitrogen metabolism, cell cycle functions, and hormonal regulation. Most studies have focused on photosynthesis and stomatal conductance in response to e[CO2], despite the emerging evidence of e[CO2]'s role in moderating secondary metabolism in plants. In this review, we briefly discuss the effects of e[CO2] on photosynthesis and stomatal conductance and then focus on the changes in other cellular mechanisms and growth processes at e[CO2] in relation to plant growth and development. Finally, knowledge gaps in understanding plant growth responses to e[CO2] have been identified with the aim of improving crop productivity under a CO2 rich atmosphere.

Rising CO 2 levels may induce nutritional deficits (protein, minerals, and vitamins) in the highest rice-consuming countries.

There are four main waste products produced during the harvesting and milling process of sugarcane: cane trash, molasses, bagasse and mill mud–boiler ash mixture. This study investigates the value proposition of different techniques currently not being adopted by the industry in the utilisation of these wastes. The study addresses the technical challenges and the environmental impact associated with these wastes and comes up with some recommendations based on the recent findings in the literature. All the biomass wastes such as bagasse, trash (tops) and trash (leaves) have shown great potential in generating higher revenue by converting them to renewable energy than burning them (wet or dry). However, the energy content in the products from all the utilisation methods is less than the energy content of the raw product. This study has found that the most profitable and challenging choice is producing ethanol or ethanol/biogas from these wastes. The authors recommend conducting more research in this field in order to help the sugar industry to compete in the international market.