Seaport footprints will need to double or quadruple in size by 2050 to cope with the combination of sea-level rise and increased freight demand, according to a model that compares trade growth and port demand with various combinations of climate policy interventions and global temperature increases.
Under the scenario with minimal greenhouse gas restrictions and maximum trade growth, the cost of building that new port capacity could reach $768 billion, compared to $223 billion for a scenario with the greatest climate intervention and the least freight growth, according to the study, “Demand for Ports to 2050: Climate Policy, Growing Trade, and the Impacts of Sea‐Level Rise.”
Either way, the investment would dwarf the costs of adapting to sea level rise, which means that incorporating climate adaptation strategies into new construction is a relatively low-cost means to prevent future disruption from the effects of climate change, according to the study’s authors, Susan E. Hanson and Robert J. Nicholls. The report was published in July in Earth’s Future, a peer-reviewed scientific journal focusing on climate change and future sustainability. It was funded by the UK Engineering and Physical Sciences Research Council and relied on research performed at the Tyndall Centre, University of Manchester, and UCL London.
“Over the coming decades, the type and amount of trade carried by sea will change, influenced by climate policy as well as other economic factors. Ports will need to respond to these indirect effects of climate change as well as more direct effects of sea‐level rise, while maintaining their efficiency and reliability as part of global trade systems,” Hanson and Nicholls wrote.
Any disruption to port capacity would have a major impact on global supply chains, since ships transport some 80% of trade goods worldwide, the study found. In response to market pressures, ports have already been expanding since the 1980s to meet growth driven by liberalization of trade, the opening of China’s economy, and increased use of shipping containers.
According to the study, recent trade scenarios suggest that global freight demand could increase between three‐ and seven‐fold by 2050, leading to a 73% global increase in the number of containers moved to at least 2.2 billion per year over the same period. Under that pressure, It has been estimated that port capacity will not be adequate to meet demand as early as 2030.
But those forecasts will likely be stressed by changing weather patterns. The study found that climate‐related extremes and trends have important implications for ports in terms of their functionality, navigable water, and shelter from wind and waves. Those implications were clear to see in the physical and economic consequences of extreme events such as Hurricanes Sandy and Katrina, which triggered significant port closures and recovery durations.
“Looking to the future, ports will therefore need to adapt to the consequences of sea‐level rise, while also responding to changes in seaborne trade. Climate policy, by influencing global temperature rise, will have an impact on both these factors,” the study found. “As adapting existing infrastructure and planning and construction of new ports is time‐consuming and will require significant capital investment…exploring the potential impact of climate policy is beneficial over both the short and long‐term.”