## 1 Introduction  
Greenhouse gas (GHGs: carbon dioxide (CO2), nitrous oxide (N2O), methane--CH4, F-gasses, and water vapour (H2O)) emissions increase across various sectors from three different base years--1990, 2005, and 2021--to 2022 as analyzed in the JRC (Joint ResearchCentre--European Commission) science for policy report on GHG emissions of all world countries [1]. The power industry has seen a significant rise in emissions, with a 92% increase from 1990 and a 34% increase from 2005, alongside a modest 1% increase from 2021 to 2022. Similarly, the industrial combustion and processes sector experienced the largest surge, with a 95% increase from 1990 and a 43% increase from 2005. In the buildings sector, emissions had a slight increase of 3% from 2005. Agriculture emissions have steadily increased by 21% from 1990, 15% from 2005, and 1% from 2021 to 2022. The transport sector shows notable emission increases across all periods, with a 72% rise from 1990, a 22% increase from 2005, and a significant 5% rise from 2021 to 2022. The fuel exploitation sector also recorded substantial increases, with a 56% rise from 1990, a 22% increase from 2005, and a 3% rise from 2021. Mathematical prediction models show that GHG emissions from the transport sector will tend to increase for most European countries for the next several years [2], while China's case shows a rise for both energy consumption and transport CO2 emissions by 2050 [3]. Modern prediction models are mostly based on neural networks, metaheuristics, prediction factor selection, or hybrid technology, and some regions like the USA show inconsistent results for future emissions [4; 5]. In contrast, low-income countries with fast GDP (gross domestic product) growth are facing a GHG emissions increase, and a decrease in energy intensity is one of this problem's solution [6]. Most nations globally are developing strategies to address climate change. The European Union (EU) is particularly proactive, with ambitious goals outlined in the European Green Deal and European Climate Law [7; 8]. The EU aims to cut its net domestic GHG emissions by a minimum of 55% by 2030 compared to 1990 levels and achieve climate neutrality (net-zero GHG emissions) by 2050 [1]. Due to the reliance on fossil fuels, the transport sector is a significant contributor to GHG emissions, while the electric vehicle's part is still increasing [9]. Domestic transportation in EU 27 (27 member states of the European Union) follows closely, contributing 23.1%, which reflects the substantial impact of vehicles and transport systems on the environment [10]. Here, emissions initially increased significantly from approximately 672 \(\mathrm{M}\mathrm{C}\mathrm{O}\mathrm{c}\mathrm{O}\mathrm{z}\) (million metric tons of carbon dioxide equivalent) in 1990 to a peak of around 863 \(\mathrm{M}\mathrm{C}\mathrm{O}\mathrm{c}\mathrm{O}\mathrm{z}\) in 2007. This represents a 28.4% increase over 17 years, driven by growing vehicle usage and economic activity. After 2007, emissions from domestic transportation began to decline; however, by 2022, emissions increased up to \(\sim\)803 \(\mathrm{M}\mathrm{C}\mathrm{O}\mathrm{c}\mathrm{O}\mathrm{z}\), reflecting a 3.8% reduction since 2014. Overall, from 1990 to 2022, there was a \(\sim\)19.5% increase in emissions, despite the recent declines. Hydrogen has emerged as a promising solution for reducing GHG emissions due to its potential for zero carbon emissions [11; 12; 13; 14; 15; 16; 17; 18; 19]. When burned, hydrogen produces only water as a by-product, thereby eliminating carbon dioxide emissions entirely [20; 21; 22]. Hydrogen's wide flammability limits and high flame propagation rates enable stable combustion, even with lean mixtures, which can significantly improve engine efficiency and reduce nitrogen oxide (\(\mathrm{NO}_{\mathrm{x}}\)) emissions [23]. Moreover, hydrogen has a higher energy content per unit mass compared to petrol, which can result in higher thermal efficiency for engines designed to utilize hydrogen effectively.