Climate mitigation in maritime transportation
CLIMATE change is the most concerning issue of this century. Human activities have increased the ambient atmospheric concentrations of Carbon Dioxide (CO2), Methane (CH4), Nitrous Oxides (N2O) and Chlorofluorocarbons (CFCs) from the pre-industrial level which is the predominant cause of increase in observed global temperature since the mid 20th century as reported in the IPCC’s Fifth Assessment report on the state of Climate Change 2014.
On 12 December 2015, parties to the United Nations Framework Convention on Climate Change (UNFCCC) embraced the Paris Climate Agreement with a promise to move on progressively for goal-oriented targets to limit the global temperature rise well below 2 degrees Celsius and preferably limit the temperature rise to 1.5 degrees above pre-industrial levels.
Response strategies under Paris Climate accord and Sustainable Development Goal (SDG)-13 were a parallel development by global stakeholders including International Maritime Organization (IMO) that aims to reduce emissions of greenhouse gases from international shipping.
According to Intergovernmental Panel on Climate Change(IPCC), transport sector is the second largest contributor to climate change.
Maritime transportation is the backbone of global trade since it contributes more than 80% of the international trade as mentioned in Review of Maritime transport 2020 by the United Nations Conference on Trade and Development (UNCTAD).There are about 96,295 merchant ships operating around the world.
Around 56,000 merchant ships including (general cargo ships 17,112, bulk carriers 12,144, crude oil tankers 8,033, chemical tankers 5,914, container ships 5,360, passenger ships 5,057, and liquefied natural gas 2,035) are trading internationally as published by Statista Research Department 2021.
Mostly, conventional fossil fuels such as heavy fuel oil (HFO) and marine diesel oil (MDO) have been consumed by ships during their journeys.
Maritime transportation accounts for 3.1% of the total global CO2 emissions which is equivalent to approximately one billion tonnes of CO2annually.
Greenhouse gases emissions from maritime transportation sector are progressively drawing public consideration.
The third GHG study 2015 of International Maritime Organization (IMO) estimated the average annual fuel consumption by shipping during the period 2007-2012.
Approximately 300 million tonnes of fossil fuels are consumed in international maritime transportation per year which brings about harmful emissions such as CO2, N2O and SOx.
GHG emissions have risen from 977 million tonnes in 2012 to 1,076 million tonnes in 2018 including an increase in Carbon Dioxide (CO2) emissions from 962 million tonnes in 2012 to 1,056 million tonnes in 2018 depending on the fossil fuel consumption as reported in Fourth IMO GHG Study 2020.
The IMO study report 2014 also projected that CO2emissions from maritime transportation are likely to increase up to 250% by the year 2050 which is quite alarming.
This rise up in emissions can be alleviated by taking effective actions and efficiency improvement.
IMO has implemented strict rules and regulations for maritime transportation in order to reduce GHG emissions (ie CO2, SOx. N2O). Regulations on Energy Efficiency for Ships are the guideline plans to control and restrict CO2 emissions of existing ships and new structure ships.
IMO has embraced obligatory measures to lessen the emissions of greenhouse gases from maritime transportation, under IMO’s Pollution Prevention Treaty (MARPOL) – the Energy Efficiency Design Index (EEDI) mandatory for new ships, and the Ship Energy Efficiency Management Plan (SEEMP).
On 13 April 2018, IMO’s Marine Protection Committee (IMO) set up an initial strategy on reduction of GHG emissions from ships.
This initial IMO GHG strategy has two aims focusing on the reduction of GHG emissions from international maritime transportation in order to contribute to the global fights against climate change.
IMO Resolution MEPC.304 (72) Annex 11 2018, titled “Initial IMO Strategy on reduction of GHG emissions from Ships”, aims to curtail CO2emissions per transport by at least 40% by 2030, and seeking to endeavour 70% by 2050, compared to the level of year 2008.
Candidate measures; short-term (2018-2023), mid-term (2023-2030) and long-term (beyond 2030), are declared by the IMO under the Initial GHG Strategy to achieve these aims.
Short term measures (2018-2023) include improvement of existing energy efficiency framework, development of operational measures for ships and initiation of an existing fleet improvement programme.
Mid-term measures (2023-2030) incorporate use of alternative fuels including low-carbon and zero-carbon fuels, operational efficiency measures to enhance performance of ships and emission reduction mechanism as well as market based measures.
Keeping in view the IMO GHG Strategy, researchers have suggested different alternative fuel options for maritime transportation, which include Liquefied natural gas (LNG), liquefied petroleum gas (LPG),hydrogen, Ammonia, biogas, biodiesel, synthetic fuels, ethane, ethanol, methanol and dimethyl ether (DME).
These alternative fuels are being considered as potential to be used for maritime transportation in order to meet the targets of low carbon alternative fuels and zero carbon alternative fuels as stated in the IMO GHG Strategy 2018.
Based on the latest state of scientific research on the topic concerned, it is concluded that Ammonia and Hydrogen are the more desirous alternative fuels because of their zero Carbon content for the absolute Carbon reduction in maritime transportation in future.
Out of these two, Ammonia is the most promising alternative fuel because it is safer fuel with lower cost and higher sustainability, provided if its slow combustion related shortcoming is removed with appropriate technological solution. It is hoped that this would become a feasible alternate fuel option soon.
It is time to fully adhere the IMO’s strategy to curtail GHG emissions in maritime transportation which is particularly important for developing countries including Pakistan, having high vulnerability index.
—The writer who is affiliated with International Islamic University.