This is the first part of a longer blog post series called The Journey. The series consists of four short articles which will address the following topics:

Part I (this post)

Impact of the shipping industry, specifically the cruise industry, on greenhouse gas emissions, including an overview of regulatory developments in the past decade.

How do different activities within the cruise ship contribute to the emissions?


What are the current steps taken to address some of these problems?


What are the potential future solutions, and how will ALFRED help decarbonize?


Impact on

Global greenhouse gas emissions are estimated to be around 50 billion tons annually [measured in carbon dioxide equivalents (CO2eq)].

The first step to determining how we can most effectively reduce emissions and what emissions can and cannot be eliminated with current technologies is to understand where our emissions come from.

The chart in this post is a breakdown of global greenhouse gas emissions by sector published by Climate Watch and the World Resources Institute. It shows the analysis of global greenhouse gas emissions by industry in 2016.

Based on this diagram, almost three-quarters of emissions are produced by energy; approximately one-fifth is generated by agriculture and land use [this figure increases to one-quarter if the food system is considered as a whole – including processing, packaging, transportation, and retail]. The remaining 8% is generated by industry and waste.

A pie chart depicting greenhouse gas emissions across sectors; Courtesy: Image via Our World in Data [OurWorldInData]

How to decarbonize the economy?

Based on this breakdown, it is clear that various sectors and processes contribute to global emissions. Consequently, there is no single or simple solution to climate change.

Energy is responsible for nearly three-quarters of all greenhouse gas emissions, but there is no simple solution to this issue. Energy is used from various sources and in various forms. If, for example, we could fully decarbonize electricity production, we still would need to greatly modify the consumer side, such as heating or road transportation systems. And even in that case there would still be emissions from e.g. shipping and aviation – for which we do not yet possess 100 % carbonless technologies for – to deal with.

We need innovations across a wide range of industries to achieve net-zero emissions. A single solution simply will not suffice.

Possible ApproacHES

Our World in Data indicates that in 2016, the transport sector contributed 16.2 % of total greenhouse gas emissions, whereas the shipping industry (including freight and passenger ships) contributed only 1.7 %. This percentage remains small, but adopting Zero Carbon technologies and energy efficiency measures significantly reduces emissions in other industries. As per Our World in Data, if left completely unregulated, shipping emissions are expected to account for 17 % of global emissions by 2050.

However, regulatory bodies, such as the International Maritime Organization and the Cruise Lines International Association, are taking steps to reduce GHG emissions from the maritime industry. Several additions to the EEDI (Energy Efficiency Design Index) and SEEMP (Ship Energy Efficiency Management Plan) have been implemented since July 2011, including, but not limited to, EEXI (Energy Efficiency Existing Ship Index) and CII (Carbon Intensity Indicator) [EnergyEfficiencyMeasures] .

There are many controversies surrounding the ultimate benefits of each, although they all aim to set good targets for vessel design, construction, and operation. As an example, the CII has been widely criticized, particularly when it comes to cruise vessels. Its fundamentals are fine; how much CO2 can be emitted over a given distance for a given good. A cruise vessel with a high service load (considered all other than propulsion) produces relatively large quantities of CO2, even on very short/slow voyages. In the current proposed CII, distance is regarded as a denominator, and maximizing distance can increase fuel consumption, resulting in higher CO2 emissions, but lower CII. This assimilates with the “Lazy ships” phenomena in cargo segment, criticized for example by Risto Kariranta in TankerOperator [CII]. One could ask would the world benefit of empty, unairconditioned cruise ships gathering mileage any more than of a cargo ship in sailing around in ballast?

Simply to achieve the required CII rating in last minute panic?

We can only expect some heated debate when the first annual CII ratings will be given in 2023.

Cruise companies have all developed strategies to minimize their carbon footprints and prepare for the regulations in addition to developing their strategy. Several studies have compared land-based hotels with these floating resorts and presented a skewed picture of the impact of cruise ships at three times that of land-based hotels in terms of greenhouse gas emissions. It would be even higher if we included the travel costs associated with these passengers flying to and from these destinations. Nevertheless, if you want to visit a far shoreside resort, you must always travel there, whereas cruise ships can come close to you, or you can choose a turnaround port that is reachable by sustainable means. Considering that the cruise industry is adaptive and proactive, operators are already taking several measures to minimize the industry’s impact on the environment. Often, this means reinventing the cruise, packaging an all-inclusive vacation in a more environmentally friendly way.

digitization opportunities

With the advent of digitalization, shipping faces numerous opportunities. Global networking, the Internet of Things, and the use of large amounts of data, along with artificial intelligence and autonomous systems, offer several options for improving the efficiency of shipping processes and procedures. Maritime transport offers several advantages through networking with partners in optimizing existing logistics chains. Information is shared in real-time and intelligent algorithms are integrated into the transportation control process. A smart container, for example, can permanently transmit its location and continuously transmit information regarding the current status of the goods it transports.


[OurWorldInData] Our World in Data:
[EnergyEfficiencyMeasures] Energy Efficiency Measures:
[CII] Tanker Operator – BIMCO and getting more from CII – Page 11

Thank you for reading – Please return back for Part II!

We would happily welcome all the feedback you might have!