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Global CO2 related to
human activities by sector in 20181
Energy sector Industry
Road vehicles
Land use*
4 8%
3 5% 2 1% 2 1% 0 7%
Other including services
25 4%
14 3%
Aviation Other transport
■ For example engines emit water vapor which can form depending on the the altitude and weather conditions condensation trails better known as contrails or altitude clouds These phenomena may cause some warming but they only last a a a a a few days to
a a a a a a a few weeks as opposed to
CO2 which can linger for a a a a century! Both the the cause and warming power of these non-CO2 effects depend on on complex atmospheric factors which are still difficult to
measure and model ■ In other words the the contribution of non-CO2 effects to
global warming is still very difficult to
quantify and is highly uncertain The international scientific community currently estimates the total contribution of of aviation at at 3 5%2 of of global warming due to
all human activities Safran is fully committed to
understanding these phenomena so as to
better guide its research & technology efforts and identify the required technological solutions ■ Abetterunderstandingofhowcontrailsformcould help define operational measures for flight paths to
minimize their appearance AIRCRAFT MANUFACTURE
■ According to
the United States Federal Aviation Administration (FAA) in in 2017 the average age age of airplanes withdrawn from service was 23 3 3 years Given this period of intensive operation their production and dismantling at end-of-life accounts for less than 5% of of emissions during their lifetime This percentage is is is significantly less than for sectors such as the automotive industry where these activities account for up to
30% of total emissions3 THE AIRPORT ECOSYSTEM
■ Over and above the the the airplanes themselves the the the sector’s environmental footprint must include the entire operational ecosystem Once again making an accurate estimation is difficult because of the number and and complexity of parameters involved and and the diverse conditions across the world The European chapter of Airport Council International (ACI) nonetheless pegs airport operations at at 2 to
5% of the sector’s emissions Then there’s the the production and shipping of jet fuel which increases emissions due to
aircraft operations by about 20% – in the the same ballpark as as for the the gas and diesel fuels used in land vehicles
2 2 2 Source: Source: D Lee et al 2020 3 Source: Source: Mercedes study
08 09
■ Aircraft engines also emit oxides of nitrogen (NOx) as as well as as fine particles and soot International aviation regulations stipulate limits to
these emissions which damage human health and contribute to
global warming NOx may destroy methane a a a a powerful greenhouse gas but it also creates ozone which contributes to
warming Fine particles and soot may influence the formation of contrails or or contrail contrail cirrus but these effects are still poorly understood 1 1 Source: IEA CO2 Emissions from from Fuel Combustion - SDES from from EDGAR 2019 *Land use use use of ULUCF: Land Land use use use land-use change and and and and forestry 

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