# Impact of Disruption on Ship Emissions in Port: Case of Pandemic in Long Beach
## 1 Introduction  
With the evolution of worldwide economic development, international and inter-regional commerce have become more prevalent [1]. In particular, due to the excellent efficiency of maritime transport, this has become the primary carriage mode for international trade [2; 3]. However, while developing the shipping industry has facilitated international trade, it has also brought environmental issues. International shipping and port activities are a contributor to problems such as emissions from ships and sea level rise [4; 5]. Ship exhaust is already a significant source of air pollution [6]. To achieve environmental sustainability in the shipping industry and reduce ship emissions, several ports have implemented technological advancements such as electrification and hybridisation of cargo-handling equipment [7; 8]. Additionally, some ports have adopted innovative port-management strategies to optimise vessel operations and scheduling, further reducing emissions [9; 10]. In addition, some ports have recently adopted multiple strategies to minimise ship emissions in the port region, such as shore power, subsidising emission reduction technologies, and fines for high emissions [11; 12]. For example, the California Air Resources Board implemented new regulations on using shore power in ports on 1 January 2014. These regulations require all vessels calling at California ports, including Los Angeles, Long Beach, San Diego, Oakland, San Francisco, and Hueneme, to comply with the restrictions. The policy requires ships calling at the above ports to utilise shore power at berth to limit ship emissions. Ships can no longer use the ship's auxiliary engines for lighting, communication, and cooling. New policies and technological advances are crucial in reducing ships' emissions. However, the outbreak of COVID-19 has brought significant disruptions to the maritimeindustry. Since early 2020, COVID-19 has swept the globe, affecting a wide range of sectors and people's daily lives [13]. Concurrently, several ports have taken strict isolation and quarantine policies to limit ship traffic activities to control the COVID pandemic [14]. Furthermore, the spread of the COVID pandemic impacted worldwide maritime shipping and human activities in the waters significantly. Existing studies show that modifications to port operations and rules have affected several maritime business sectors, including tankers, fishing, passenger ships, and cruise ships [15]. Before the last decade, the approach to calculating ship emissions was mainly a top-down approach [16]. Calculations were made using the ship's total fuel consumption. In more recent years, with global positioning technology developing, and the mandatory use of the Automatic Identification System (AIS), various studies have investigated ship emissions based on bottom-up approaches [17; 18]. However, there has been limited research on the impact of the COVID pandemic spread on ship emissions, even though several studies dealing with the calculation of ship emissions have lately been conducted. The Port of Long Beach (POLB), one of the busiest ports globally, has many ships arriving to operate at the port daily. However, like many other ports, it has been affected by the COVID-19 pandemic, which has had a significant impact on vessel operations. As a result, efforts to promote environmental sustainability in shipping may be affected as well. Therefore, we were inspired to use the POLB as an example to calculate the impact of this pandemic on port-wide emissions and analyse the significance of the realisation of the shore power policy. Ships' emissions affect the marine ecosystem and offshore environment. Several factors will affect ship emissions, such as international trade demand, port operations, and ship operating patterns. Some studies have concentrated on quantifying ship emissions to identify how to lessen their environmental impact precisely.