Cargo shipping is a massive contributor to emissions, and shipping technology has not quite reached the level where we can suddenly swap fossil fuel-burning engines for electric ones. This makes decarbonizing a port a difficult process, which is something many cities are trying to do one step at a time.

In Norway, the Port of Oslo has an ambitious goal: slashing emissions by 85 percent by 2030. The port, which produces 55,000 metric tons of greenhouse gas emissions a year due to ships and shore equipment, wants to eventually become the world’s first zero-emissions port.

To make this happen, the port has a 17-point climate action plan that includes installing clean shore power, using zero-emission port equipment and implementing a low-carbon contracting process. The port is also occupied with addressing the emissions that come from local ferries since they are responsible for nearly 40 percent of emissions. Thus far, the port has tasked a company named Norled to electrify three of 10 existing passenger ships. The first electric refit arrived in September and has the equivalent of 20 Tesla batteries on board.

Progress is slower when it comes to bigger ships. Cruise and cargo ships still can’t cross an ocean on battery power alone because of the cumbersome size and weight of the required batteries. Hydrogen is gaining traction as an environmentally friendly option compatible with long-haul shipping because the fuel emits water and can be produced with renewable electricity. Unfortunately, it’s also prohibitively expensive at this early stage in its maritime-sector development.

Many ports, from Baku to Rotterdam, are taking similar steps to cut emissions. Hopefully, their combined efforts can lead to new technological advancements that will help clean up the world’s ports.