Connaître et réduire les impacts négatifs des transports

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En provenance du cours de École des Ponts ParisTech

Mobilités et véhicules électriques

42 notes

École des Ponts ParisTech

Mobilités et véhicules électriques

42 notes

L’objectif de ce MOOC est d’aider ses apprenants, quel que soit leur profil, leur formation ou leur pays d’origine, à construire une réponse personnelle à des questions comme celles-ci : - Les voitures électriques seront-elles les dernières à circuler dans les métropoles du XXI° siècle ? - Le gain environnemental associé à l’électrification des véhicules justifie-t-il des investissements massifs dans les infrastructures de charge ? - Le véhicule électrique est-il réservé aux riches des pays du Nord ? Grâce à ce MOOC, les participants pourront acquérir des connaissances issues des sciences de l’ingénieur, de la sociologie, des sciences de l’environnement, de l’économie, de la géographie et des sciences politiques pour évaluer, analyser et mettre en œuvre le déploiement des véhicules électriques là où il est pertinent. Le Groupe Renault et les écoles de ParisTech collaborent depuis bientôt 15 ans sur des sujets liés à la mobilité durable. Ensemble, ils ont créé deux Masters (Transport et développement durable en 2004, Mobilité et véhicules électriques en 2010) et l’Institut de la Mobilité Durable (IMD), en 2009, pour accompagner les mutations en cours. Le MOOC Mobilités et véhicules électriques est issu de cette histoire commune et a été élaboré à partir d'un cours délivré au sein du Master Mobilités et Véhicules Électriques, piloté par Arts et Métiers ParisTech en partenariat avec Ensta ParisTech, Mines ParisTech et l’École des Ponts ParisTech. Ce cours est en français, cependant des sous-titres en anglais sont disponibles pour toutes les vidéos et vous pouvez écrire vos messages dans le forum en anglais si vous le désirez./ This course is given in French, nevertheless English subtitles are available for all videos and you can write your posts in the forum in English if desired.

À partir de la leçon

Chapitre 2 - Mobilités électriques et réduction de l'impact environnemental

<p>Dans ce chapitre, nous étudierons les enjeux des changements climatiques puis mènerons une analyse prospective quant aux évolutions des émissions de gaz à effet de serre tout au long du XXI° siècle. <br/>Nous examinerons ensuite le rôle des transports en termes de pollution locale de l'air et de bruit.<br/> Pour pouvoir déterminer la performance environnementale des différents types de véhicules, nous présenterons l'analyse de cycle de vie puis mobiliserons cette méthode pour comparer les performances des véhicules thermiques et électriques en termes de préservation de l'environnement local et global.</p><p>Le chapitre est constitué de 6 vidéos de cours et d'un <em>Point méthode</em> permettant de définir ce qu'est l'analyse de cycle de vie. Il est complété par un entretien avec un expert du groupe Renault pour traiter spécifiquement du sujet des batteries du point de vue de leur impact sur l'environnement. Il se conclut bien entendu par une évaluation sous forme de quiz. Cette évaluation ne porte que sur les vidéos de cours et est notée.</p>

Connaître et réduire les impacts négatifs des transports11:16

Rencontrer les enseignants

Virginie BOUTUEIL
Researcher
LVMT (City Mobility Transport Lab), École des Ponts ParisTech
Émeric FORTIN
Head of the Master in Transport and Sustainable Development
Direction of Studies, École des Ponts ParisTech

-Let us take stock

of the impact of transportation in terms of emissions

of atmospheric pollutants, greenhouse gases

or any other externalities generated by transportation.

You may not be aware of it, but transportation stands

for over half of the global oil consumption,

more precisely 64% of our final oil consumption.

In addition, it represents 14%

of all greenhouse gas emissions.

As you saw in the video about climate change,

65% of greenhouse gases

are linked to CO2 emissions due to fossil fuel combustion.

In France, the electric sector emits very little as it is mostly nuclear

whereas in other countries, it is often the first emitter,

so the emissions of other sectors appear higher in comparison.

So transportation represents 28% of greenhouse gas emissions in France.

In terms of atmospheric pollution,

transportation is often blamed for particle emissions

but it only stands for part of it,

16% for the larger particles, PM10,

and 19% for the smallest and most detrimental for our health.

However, transportation represents 61% of nitrogen oxide emissions,

be they monoxide or dioxide, which cause ozone peaks,

the often-mentioned pollution peaks

which lead to circulation restriction measures

in several European countries.

Transportation also represents

8% of organic volatile compound emissions.

Transportation also has high externalities

in terms of accidentology

since it represents 1.3 million deaths and 40 millions casualties per year

on a global scale.

It is also an extremely important vector for economic growth.

It accounts for 7.8% of the French GDP,

more or less equally divided

between the production of the automotive industry

and equipment manufacturers, in the widest sense,

and a little over half for transportation services,

both transportation and logistics.

Nowadays, in the world, over 1.4 billion cars are in circulation,

each requiring the mobilization of one tonne of raw materials,

which is highly challenging for mineral resources.

Lastly, transportation accounts

for 22% of the budget for each region in France

and 13.2% of household budgets.

The share of transportation among other sectors

in terms of greenhouse gas emissions,

only places it in fourth place. The largest greenhouse gas emitter

is energy transformation.

This energy will be used by industries or buildings

as heating or lighting.

In second place, we find agriculture which emits methane

during its processes and CO2 because of changes in land use.

In third place comes industry.

Transportation is in fourth place and represents on a global scale

and a European scale, 14% of greenhouse gas emissions.

However, one important difference with other sectors

is that this graph shows you

the European emissions of various sectors.

They are decreasing in all except for transportation

where they increased greatly between 1990 and 2008,

when the crisis started.

They reached an asymptote

and only then did the greenhouse gas emissions start to decrease.

In the world, mobility is skyrocketing

and greenhouse gas emissions associated with it skyrocket too.

The technical gains in terms of vehicle consumption

do not offset the great increase in mobility

and the number of kilometers traveled either by people or goods.

This graph also shows that the wealthiest travel more.

So the trend is for developing countries

to see a strong increase in mobility

to catch up with developed countries,

which will lead to a strong growth in greenhouse gas emissions

due to transportation.

It is not all doom and gloom,

as for instance, we have observed that the quality of outside air

is improving in developed countries.

It is the conjunction of many factors. In transportation especially,

it comes from the implementation since 1990,

of successive Euro standards, the current one being Euro 6.

It has led to drastic reductions of vehicle emissions.

Nowadays, one vehicle following Euro 6 emits 98% fewer NOx,

than a vehicle from 1990.

The same goes for carbon monoxide and particles.

The standards led to a strong decrease,

even if vehicle performance is still under question.

The emissions under real conditions are not the same as during testing,

but as a whole, emissions have largely decreased.

This was observed in terms of actual emissions

on the ground, especially in Europe.

The same goes for CO2 emissions. There are standards

for consumption per vehicle.

In various countries,

these standards led to a clear decrease of consumption

and thus of authorized greenhouse gas emissions

for newly-launched vehicles everywhere in the world.

What is important is that, in transportation,

there is an opposition between the reduction of atmospheric pollution

and of greenhouse gas emissions.

For instance, to reduce greenhouse gas emissions,

we may have to encourage dieselization

which would lead to more particle and nitrogen oxide emissions.

So we sometimes have to make a choice.

It is important to have a systemic approach.

This diagram shows a life-cycle assessment

which shows that to evaluate any vehicle's performance,

we must take into account

the production phase, the use phase, the maintenance phase,

the end-of-life phase, to compare various technical solutions.

And what you want to implement on a vehicle

to improve its environmental performance must

improve it throughout the whole cycle, and not favor one phase.

In life-cycle assessments, various environmental dimensions

are considered,

acidification, eutrophication, greenhouse gas emissions,

the use of non-renewable resources, ionization,

whether you are implementing electric vehicles using nuclear energy, etc.

It is important to evaluate vehicle performance

on all environmental dimensions.

So we need to have a systemic approach

to evaluate transportation system performance.

What are the prospects

for transportation system performance improvement?

First, there is the technical aspect of performance improvement

first through the use of fuels other than fossil fuels,

electricity, hydrogen, agrofuels.

It also implies a reduction of vehicle consumption

based on three principles.

First, by reducing rolling resistance,

resistance to the road and to the air thanks to aerodynamics.

Then, by making the vehicle lighter.

A lighter vehicle consumes less and emits fewer pollutants.

Finally, improving the powertrain performance

with an improvement in combustion for thermal vehicles

and any conceivable hybridization solution to improve performance.

Lastly, a good vehicle will be efficient if it is properly driven.

So it is important to develop eco-driving training strategies

to optimize the vehicles' performance.

Engineering can also influence the systems' performances

through traffic management,

using methods to improve traffic fluidity,

through standard traffic engineering

as well as the use of digital tools to reroute vehicles

in case of jams at a given place

or simply to manage in real time

the best possible affectation of vehicles to the various lanes.

The second main issue to improve transportation system performance

is to change our vectors

and to create a modal shift whenever possible.

Nowadays, individual cars represent over 80%

of the trips made in all countries,

even those with important collective transportation systems,

such as France.

So it important to be able to foster alternatives to individual cars

as well as to increase the use rate of individual cars

because one car carrying three people will emit

about the same as a car carrying one.

But for each person, the pollutant emissions will be divided by three.

We also need to tackle the source of the issue

and try and reduce all involuntary movement

by changing the shape of our cities,

their functional diversity,

and our lifestyle in order to reduce our movements

to voluntary movements only without involuntary movements.

As a conclusion,

there are a lot of externalities linked to transportation

in various dimensions.

In some dimensions, performance is improving

but transportation is still causing a lot of damage

regarding public health and quality of life.

But it is important,

since transportation causes damages from various natures,

to have a systemic approach

to avoid creating a new problem while fixing another.

Lastly, we will not be able to have zero-pollution transportation systems

whether in terms of greenhouse gas emissions or atmospheric pollutants

without implementing electric mobility.

Improving thermal mobility performance will never be enough.

So we need to aim for electric mobility.

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