Transport
Historically, energy has been linked to humanity and development, especially referring to transport. The industrial revolution began with the invention of James Watt’s steam engine in 1768 and the evolution of the means of transport used up to date.
The first locomotive powered by a coal-fired steam system came onto the market in the early 19th century, managing to transport 40 tons of freight at a top speed of six kilometres per hour.
From this first locomotive with a cargo capacity of 40 tonnes to the large container ships sailing today, which can carry up to 60.000 tonnes (New Panamax ship with 15,000 TEUs), there has been a great development in the transport industry and fuel options to supply it. Coal gave way to oil derivatives and other type of fuels such as gas, electricity, or hydrogen, which can be obtained mainly from renewable energies, are now gaining strength in the market.
This type of energy helps to reduce exponentially the carbon footprint that globalisation brings about, due to the increase of demand for transport of people and goods worldwide.
Focusing on the transport expense over the last decades at European level, it has diminished only by unavoidable world events (2008 crisis and the COVID-19 pandemic), we can observe that the “movement trend” is unstoppable.

Figure 1. Evolution of the logistics market from 2007 to 2021 in Europe. Source: (Deutsche Verkehrs-Zeitung
Currently, and derived among other factors about this rising trend in the consumption of services such as transport, the member countries of the United Nations (UN) have focused on passing laws that comply with the resolutions of the 2015 Paris Agreement on emissions reduction. The Law 7/2021 of 20 May on climate change and energy transition is an example of this.
Nowadays, in Spain, according to the BOE published on May 21st 2021 the road transport sector means a 25% of the country’s greenhouse gas emissions, being one of the main barriers to decarbonisation because the insufficient development of electric charging infrastructures.
For this reason, the public sector is working to expand the network of charging points throughout the country. There are currently around 21,500 charging points installed, of which approximately 65% are fast chargers, compared to the 45,000 public access chargers that the State had set as an initial target to be met by 2023 (as indicated by the Spanish Association of Car and Truck Manufacturers) and the 240,000 that, according to the electric mobility yearbook, are expected to be reached by 2030.
This promotion of charging points in conjunction with penalties in terms of taxes and access restrictions in large cities, makes more attractive to purchase private and public means of transport, passenger and/or freight, changing radically road transport trends in the national territory. This is equally reflected in vehicle sales worldwide, with a gradual roll-out, but is does not reach international targets.

Figure 2. Global Electric Vehicle Sales. Year 2022
The aviation sector is becoming fundamental for the global economy because of its key role in trade, tourism and investment. Today more than ever, sustainable alternatives are being sought to avoid a return to pre-pandemic emissions ratios, where aviation produced around one billion tonnes of carbon, 3% of all global emissions.
Changing this trend in this type of transport is a challenge, as the introduction of sustainable fuels in the aeronautical sector will have the greatest impact on the carbon footprint rate on transport prices, whose cost is expected to be assumed by the end consumer. Consumer associations consider that a good investment in the development and production of these fuels is vital to avoid surcharges falling directly on the user.
Maritime transport is particularly linked to the movement of consumable goods worldwide. It accounts for about 90% of global freight traffic and 2.5% of total carbon emissions into the atmosphere, according to the International Maritime Organisation (IMO). To try to reduce the impact of this traffic, the IMO has developed a series of measures that will be mandatory for all maritime operators from January 2023.
Cargo ships have already an energy classification previously deployed in other sectors. Thus, carbon intensity indicators are assigned using a code following the first letters of the alphabet: A, B, C, D, E, with “A” being the best rated. In case of not achieving the “C” classification, the ship may stay dry-docked for retrofitting or having to use some containment measures to reach the maximum allowable emissions. Some of the proposed mitigation measures include reducing transit speeds, optimising auto pilots and starter generators, or even changing the routes of the most polluting ships over shorter distances.
With all these measures, the IMO aims to reduce the carbon intensity of shipping by at least 40% by the end of 2030, and to achieve an ambitious final goal: a zero-greenhouse gas (GHG) emissions policy by 2050, as well as the commitment to ensure the adoption of zero-CO2 alternative fuels.

Figure 3. Global CO2 emissions from the transport sector between 1990 and 2021 by region. Source: European Comision
Inevitably, all these changes will also involve large investments. Industries and commercial sectors accuse different organizations involved of trying to mitigate the increase of emissions by paying emission charges, such as waste registers, declarations of non-reused plastics or applying driving and parking restrictions for non-electric vehicles, instead of devoting resources to research and provide alternative renewable energy fuels with lower emissions of particulate contaminants.
In any case, good environmental policies promote awareness of people who use means of transport and the consumption patterns of industries and final consumers. Using alternative fuels, produced from renewable resources that are often an endless source of energy, will be vital for the sustainable development of our planet.