徵收碳稅對船舶減速與營運成本間之影響評估

ASSESSMENT OF THE IMPACT OF A CARBON TAX ON SPEED REDUCTIONS AND OPERATING COSTS IN SHIPPING

本文依據船舶燃油消耗量與燃油排放係數，進行分析國際海運產業主要船型（包括海岬型散裝船、輕便型散裝船、超大型油輪、輕便型成品油油輪、次巴拿馬型貨櫃輪與輕便型貨櫃船）之溫室氣體排放量，並模擬在徵收碳稅的情境下，對於航運業者營運成本之影響。首先估計各種船舶之溫室氣體排放量時，發現高速貨櫃船與小型船舶之單位排放量（公克／延噸海浬）高於其他船舶。而在模擬徵收碳稅對營運成本之影響時，燃油費用支出較高之船舶營運者會受到碳稅徵收之誘導，採取降速策略，以獲取降速節省之營運支出，降低碳稅之衝擊。本文同時也建構溫室氣體排放矩陣，有效檢視各種船舶排放量所屬區域，可以作為分級徵收碳稅的參考。

This paper presents an analysis of greenhouses gas emissions (GHG) for major ship types (capsize bulk carriers, handy-size bulk carriers, very large crude oil tankers, product tankers, sub-panamax container vessels and handy-size container vessels) based on the fuel consumption and emission factors for the fuel, and a simulation of the impact on shipping operating costs from adding a carbon tax to the fuel cost. The estimated GHG (grams of CO2 per ton per nautical mile) showed that the small-sized and high speed container vessel had higher emission volumes than the other types of ships. The adoption of a fuel tax will lead to higher fuel costs for vessel owners and operators, who will thus need to offset these by reducing the speed of the ships. This paper also establishes an emission assessment matrix that makes it possible to evaluate the level of emissions for different types of ships, thus enabling the determination of an appropriate level of carbon tax on fuel.