Towards a Sustainable Growth of the Shipping Sector—A Systematic Review of Future Shipping Emissions Scenarios

Abstract

The demand for transport could be tripling by 2050, and it is expected that the increase in shipping demand will be even larger. Considering this, it is important to forecast the evolution of ship emissions in the coming decades and estimate their impacts on air quality, health and climate as reliably as possible. Thus, this study aimed to perform a systematic review considering studies where future shipping emissions scenarios have been established and studies that used future shipping emissions scenarios to assess future impacts on air quality and/or health and on climate. The 26 studies reviewed were performed mainly for the Arctic, Baltic and North Seas regions and Asia. Most authors reported a general decrease in SOx, NOx and PM2.5 concentrations (and consequent health impacts where applicable) and in the deposition of sulphur and nitrogen species due to the NOx and SOx emission regulations. In contrast, the authors reported that the current regulatory energy efficiency policies might not compensate for the increase in traffic and the resulting CO2 emissions. The health effects of future ship-related emissions were rarely reported. Moreover, based on considerations of studies across the globe, future studies should adopt a holistic approach that integrates, besides what was already explored, detailed traffic growth assumptions, alternative fuels and technologies (LNG, scrubbers and shore electricity), economic factors and more reliable methods to forecast the future activity of the ships.