Facing global warming and recent bans on the use of diesel in vehicles, there is a growing need to develop vehicles powered by renewable energy sources to mitigate greenhouse gas and pollutant emissions. Among the various forms of non-fossil energy for vehicles, hydrogen fuel is emerging as a promising way to combat global warming. To date, most studies on vehicle carbon emissions have focused on diesel and electric vehicles (EVs). Emission assessment methodologies are usually developed for fast-moving consumer goods (FMCG) which are non-durable household goods such as packaged foods, beverages, and toiletries instead of vehicle products. There is an increase in the number of articles addressing the product carbon footprint (PCF) of hydrogen fuel cell vehicles in the recent years, while relatively little research focuses on both vehicle PCF and fuel cycle. Zero-emission vehicles initiative has also brought the importance of investigating the emission throughout the fuel cycle of hydrogen fuel cell and its environmental impact. To address these gaps, this study uses the life-cycle assessment (LCA) process of GREET (greenhouse gases, regulated emissions, and energy use in transportation) to compare the PCF of an EV (Tesla Model 3) and a hydrogen fuel cell car (Toyota MIRAI). According to the GREET results, the fuel cycle contributes significantly to the PCF of both vehicles. The findings also reveal the need for greater transparency in the disclosure of relevant information on the PCF methodology adopted by vehicle manufacturers to enable comparison of their vehicles’ emissions. Future work will include examining the best practices of PCF reporting for vehicles powered by renewable energy sources as well as examining the carbon footprints of hydrogen production technologies based on different methodologies.

Fast-changing fashion trends have resulted in increases in textile production and waste generation. The environmental impacts of the production, consumption and end-of-life of textiles are amply documented. Therefore, the industry has started to shift from the linear economy principle of ‘take-make-waste’ to the circular economy concept, where textiles can reenter the life cycle rather than being wasted and thus form a closed loop, resulting in resource savings and reduced environmental impacts. To this end, valorization of solid waste streams from the textile industry to recover fibers and marketable value-added products has gained increasing attention in recent years. Textile waste valorization involves three main steps: pretreatment, enzymatic hydrolysis and fiber regeneration. This review presents the main methodologies and the most recent technical developments in these valorization strategies, the value-added products obtained and their applications. Furthermore, the review describes fermentative products synthesized using cellulosic glucose from the cotton fraction of waste streams. Gaps and challenges in existing strategies are identified for potential future research. This review will help to apprize researchers and practitioners of important recent developments in effective textile valorization via upcycling and guide them in the design of efficient strategies for sustainable management of textile waste streams. Graphical abstract