Transport And Climate Change

Transport contributes a huge share of greenhouse gas emissions that are responsible for climate change. Transport constitutes 14 % of emissions on its own, and 23% of emissions from the energy sector. Globally, energy is the source of two thirds of all emissions. As it is currently, 95% of transport is propelled by fossil fuels mainly coal and oil.

The transport sector is broad, and touches on several sustainable goals namely affordable and clean energy which is goal 7, goal 9 which is industry, innovation and infrastructure, goal 11 which is sustainable cities and communities and goal 13 which is climate action. Cheap and reliable transport is also a crucial part of economic growth, covered by goal 8.

Transport can be broadly categorized into four namely shipping, aviation, rail and vehicles. Let us start with ships.

Most of the world’s trade is done through sea, about 80% of global trade is through ships.

Shipping as an industry is responsible for 3% of global emissions and produces a billion tons of carbon dioxide annually. If this entire maritime industry could be quantified, it would rank number six directly behind Russia and Japan. For the industry to be climate compliant in line with the Paris Agreement, it would need a cut of roughly 80% of emissions by the end of the 2020s, that is, by 2030.

A cruise ship on the high seas - image courtesy

 

 

 

 

 

Ships contribute to warming by their use of heavy fuel oil. This marine fuel produces particles of solids known as black carbon. These particles absorb heat in the air adding to the greenhouse effect. Ships also produce aerosols, as well as carbon dioxide and nitrous oxides, which are regulated greenhouse gases. Black carbon is responsible for a fifth of all warming caused by ships.

Shipping is mainly regulated by the United Nation’s International Maritime Organization (IMO). 3 years ago, in 2018, the IMO decided on a goal to reduce emissions by 50% by 2050 as measured by 2008 levels. It targets a quick peak of shipping emissions and also deep cuts in emissions in the sector as well. In particular, it aims for a drop of 40% of carbon dioxide emissions by 2030, graduated to 70% by half century. Industry stakeholders have however called for net zero emissions by 2050 and also a carbon tax.

Unfortunately, due to the growth rate of the industry, shipping is projected to be take up around 10% of all global greenhouse gas emissions by half century mark, that is, by 2050. One of the proposals to make this sector environmentally clean is the use of alternative fuels such as ammonia or methanol, wind power and hydrogen cells. Natural gas, though a fossil fuel, has lower emissions than coal or oil and can be solidified to be used as fuel.

Another way is to build more energy efficient engines. The IMO has laid out a strategy that ships built by 2025 should be 30% more energy efficient than those built in 2014. Slow steaming is whereby the engine is not used at full capacity and so less emissions are produced. Another method would be to use air lubrication. Fuel switching from high sulphur oil to low sulphur oil is recommended to reduce air pollution by sulphur(IV)oxide. This is particularly a human health concern.

The aviation industry produced 1.9% of greenhouse gases as of 2018. In particular, it produces 2.5 % of all carbon dioxide emissions. 70% of plane exhaust is carbon dioxide. However, this is not the only way that airplanes warm the atmosphere. Planes produce water vapor contained in the water trails released from their engines. These trails are usually visible as white tails behind the plane. Water vapor produces the greenhouse effect on its own, and solidifies to ice, combines with other particulates from the exhaust to form thin cirrus clouds known as contrails. These contrails act in the same way greenhouse gases do and are particularly potent, absorbing heat at high rates thus affecting climate. Airplanes also produce aerosols and contribute to ozone formation, both of which affect climate by cooling and warming. Planes also produce soot which basically absorbs heat.

Therefore, when all the above is taken into account, aviation is responsible for 3.5 % of all warming. Airplanes use a type of fuel known as jet gasoline/kerosene which produces carbon dioxide on combustion. In 2018, this sector was found to release 1.04 billion tons of carbon dioxide globally. It is estimated that aviation CO2 emissions have grown by 32% from 2013 to 2018.

Flying when compared to vehicular transport may not attract as much attention. This is because far many more people travel by road than using planes. Only a small percentage of the global population regularly fly, yet it is this small percentage that is of major consequence. Why? Because planes emit more than the average car. Frequent flyers have a considerable carbon footprint especially those who travel first class or business class.

There are several proposals for cleaning up the aviation industry. An example is Airbus which has proposed the use of hydrogen fuel cells by 2035, and eventual use of electric planes. A good practical solution would include carrying less baggage and use of renewable fuels such as from biomass.

Airports on their own can be sources of greenhouses and so there is concerted effort to make them climate friendly and particularly carbon neutral. This is by tallying all the sources and quantities of emissions. Emissions from operations at the airport for example from heating and cooling, vehicles, auxiliary engines and other sources needs to be completely reduced or offset.

Many airports globally have undertaken to be part of this initiative, by using renewables, reducing number of cars and use of insulating material to save on heating and lighting. A good example would be Jomo Kenyatta International Airport in Kenya and OR Tambo airport in South Africa.

Transport by rail is the preferred method especially for moving cargo inland from place to place. The traditional diesel trains of course produce emissions from using diesel for fuel. Electric trains are climate friendly because they release no emissions during operation but possibly during manufacture. It also depends on whether the source of electricity is renewable or non-renewable. Countries like France which generate power from nuclear plants produce very little emissions from their electric trains. Another way emissions are produced from rail transport is the building and maintenance of rail infrastructure.

Steam trains which were formerly widely used were powered by burning coal to produce steam which powered the engine.

Rail road transport has several advantages namely, the ability to reach the heart of cities, nearer to the venues which is convenient. They can also be built underground and so occupy less space.

Cars are the most common method of transport. There are over a billion cars on the planet, most of which are powered by fossil fuels. Majority of cars are by nature dirty for climate because at every stage, they use fossil fuels. During manufacture, use and disassembly, they use energy derived from fossil fuels.

Estimates have it that highway vehicles use 1.6 billion tons of carbon dioxide yearly. Tailpipe emissions in particular release carbon dioxide, methane and ground level ozone. All these gases have a climate warming effect. The solutions for this sector include use of methane based fuels, use of electric vehicles, low emission cars, use of technology to block particulate matter, building more energy efficient engines, use of liquefied natural gas as a fuel for cars, and utilization of biofuels like ethanol.

Electric vehicles are set to become the future of vehicular transport given the growth rates in countries like the U.S.A and Norway. These vehicles release no emissions except at the manufacture phase and emissions from electricity generated from non-renewables.

They are still a better alternative to the conventional car because they produce lesser emissions throughout their lifetime; from design, manufacture to use.

Another solution would be to take into account the needs of the human population during urban planning. Cities should be built for people, not for cars.

One way is to encourage people to walk as much as possible and legally protected walkways constructed. Cycling produces no emissions and is good for the human health. Amsterdam is an example of this. Another way is to design good and efficient public transport and encourage people to use it. Carpooling in terms of private transport would reduce emissions per person because they are shared yet the same amount of fuel is used.

The use of coaches, although falling under vehicular transport, is a better alternative for long distance transport than individual means of transport.

In conclusion, the transport sector is a major contributor to climate change, but there are real and green solutions to make the sector climate friendly. However, there needs to be consensus and spirited political action and legal framework to make decarbonization a reality.

Transport is a necessary part of life, so cheap, readily available and green ways of transport are one of the things that are required for a low carbon pathway of development and will help the planet collectively to reach the goal of net zero emissions by 2050.