From 00f3cfbc12e134b25e1ee4037ebed8a1c9bed9e1 Mon Sep 17 00:00:00 2001 From: Jorge Leitao Date: Sun, 28 Jan 2024 18:45:49 +0100 Subject: [PATCH] Improved methodology --- methodology.md | 20 +++++++++++--------- src/private_emissions.rs | 14 ++++++++++++-- 2 files changed, 23 insertions(+), 11 deletions(-) diff --git a/methodology.md b/methodology.md index aab879a..5172289 100644 --- a/methodology.md +++ b/methodology.md @@ -78,10 +78,6 @@ Details are available in the source code, [src/emissions.rs](./src/emissions.rs) ### M-6: Consumption of private jet -This was performed by a human, and consisted in going through different aircraft -manufacturers' websites and identifying the aircrafts that were advertised as used -for private flying. - This was performed by a human, and consisted: * access websites of companies that sell private jets * extract the consumption in gallons per hour (GPH) of each private jet model @@ -93,21 +89,27 @@ This was performed automatically by the program and consisted in performing the following calculation: ``` -leg emissions [kg CO2] = +leg emissions [kg CO2e] = consumption [gallon/h] x liters / gallons [L/gallon] x liters to kg of jet fuel [L/kg] x emissions per kg [kg CO2 / kg jet fuel] + x Radiative Forcing index [kg CO2e / kg CO2] + x Life-cycle emissions [kg CO2e / kg CO2] x leg time [h] + x occupancy [1/person] ``` Where: -* `consumption [gallon/h]` is obtained via the methodology `M-6` in this document. -* `liters / gallons [L/gallon] = 3.78541 [L/gallon]`, as specified in [NIST's guide to SI](https://nvlpubs.nist.gov/nistpubs/Legacy/SP/nistspecialpublication811e2008.pdf) -* `liters to kg of jet fuel A-1 [kg/L] = 0.8 [kg/L]`, as [recommended by ICAO](https://data.icao.int/newDataPlus/content/docs/glossary.pdf) -* `emissions per kg = 3.16 [kg CO2 / kg jet fuel]`, as used on [ICAO Carbon Emissions Calculator Methodology, v12 from Sep. 2023](https://applications.icao.int/icec/Methodology%20ICAO%20Carbon%20Calculator_v12-2023.pdf) +* `consumption` is obtained via the methodology `M-6` in this document. +* `liters / gallons = 3.78541 [L/gallon]`, as specified in [NIST's guide to SI](https://nvlpubs.nist.gov/nistpubs/Legacy/SP/nistspecialpublication811e2008.pdf) +* `liters to kg of jet fuel A-1 = 0.8 [kg/L]`, as [recommended by ICAO](https://data.icao.int/newDataPlus/content/docs/glossary.pdf) +* `emissions per kg = 3.16 [kg CO2 / kg jet fuel]`, as used on [ICAO Carbon Emissions Calculator Methodology, v12 from Sep. 2023](https://applications.icao.int/icec/Methodology%20ICAO%20Carbon%20Calculator_v12-2023.pdf) +* `Radiative Forcing index = 3 [kg CO2e / kg CO2]`, as concluded by [The contribution of global aviation to anthropogenic climate forcing for 2000 to 2018](https://www.sciencedirect.com/science/article/pii/S1352231020305689), from 2021. +* `Life-cycle emissions = 1.68 [kg CO2e / kg CO2]`, [Life Cycle Greenhouse Gas Emissions from Alternative Jet Fuels v1.2](https://web.mit.edu/aeroastro/partner/reports/proj28/partner-proj28-2010-001.pdf) from 2010-06, accessed 2024-01-28. * `leg time [h]` is obtained by computing the time difference between the last and first position of the leg, identified via the methodology `M-4` in this document. +* `occupancy = 0.23 [1/person] = 1/4.3 [1/person]` obtained from [Average number of passengers per flight who flew private worldwide from 2016 to 2019](https://www.statista.com/statistics/1171518/private-jet-per-flight/), where there were 4.3 passagers per flight in 2019, accessed 2024-01-28. ### M-8: Identify aircraft owner in Denmark diff --git a/src/private_emissions.rs b/src/private_emissions.rs index 6770b6c..fa4548f 100644 --- a/src/private_emissions.rs +++ b/src/private_emissions.rs @@ -1,11 +1,21 @@ static LITER_PER_GALON: f64 = 3.78541; static KG_PER_LITER: f64 = 0.8; static EMISSIONS_PER_KG: f64 = 3.16; +static RADIATIVE_INDEX: f64 = 3.0; +static LIFE_CYCLE_FACTOR: f64 = 1.68; +static OCCUPANCY_FACTOR: f64 = 0.23; -/// Returns the total CO2 emissions in kg of an aircraft with a given +/// Returns the total CO2 emissions in kg of a private jet with a given /// consumption (in GPH) of Jet-A fuel flying for a given amount of time, /// as specified in [methodology `M-7`](../methodology.md). pub fn leg_co2_kg(consumption: f64, duration: time::Duration) -> f64 { let hours = duration.as_seconds_f64() / 60.0 / 60.0; - consumption * hours * LITER_PER_GALON * KG_PER_LITER * EMISSIONS_PER_KG + consumption + * hours + * LITER_PER_GALON + * KG_PER_LITER + * EMISSIONS_PER_KG + * RADIATIVE_INDEX + * LIFE_CYCLE_FACTOR + * OCCUPANCY_FACTOR }