How we Calculate Emissions

CarbonBuddy emission calculation and offset tools utilize resources provided by the Greenhouse Gas Protocol (GHGP) as well as tools and resources of the United States Environmental Protection Agency (EPA) and the World Bank. In addition, CarbonBuddy is constantly seeking new input from peer review studies (i. e. this one on diet in the EU) focusing on emission measurement to refine the calculations provided to you.

Please continue reading for a more detailed description on how we calculate emissions.

With our calculation tools, we aim to provide tools that give you an estimation of your emissions. Furthermore, we aim to find a balance between accuracy (level of detail) and user friendliness (amount of time you need to spend). Within tools for individual use, you might be asked to select a level of accuracy depending on how much time you want to spend. Our goal is to reach as many as we can, while providing reliable tools that will enable you to understand your part in climate change. If you have comments or questions on our calculators, please write us at: emission.calculator@carbonbuddy.com

Hawai'i specific

App & International Calculators

International air travel emissions (Air-travel Emission Calculation and Offset Tool & Global Citizen & Global Small Business Emission Calculation and Offset Tool)

Emissions are calculated based on the duration of flights. Flight emissions for available categories and classes are based on average emissions of flights from KOA-LIH and MUC-LHR (short-haul) as well as LAX-OMA, DEN-JFK, LAX-JFK, HNL-ORD, HNL-BOS, LAX-MUC and CDG-HND (long-haul). Distances between airports are measured using the Google Earth Pro software. Distances (passenger miles) are used to calculate emissions using GHGP Mobile Combustion Tool V2.6. Emissions of the sample trips are then divided by flight duration in hours to obtain emissions per hour of flight time. This is repeated for each flight class.

Inter-Island travel emissions (Hawai'i calculators only)

Distances between airports are measured using the Google Earth Pro software. Distances between airports (plus 15 miles) (passenger miles) are used to calculate emissions using GHGP Mobile Combustion Tool V2.6. The calculation represents an average between different flight classes and is not airplane specific.

The following airports are used to determine Inter-Island emissions:

·         Kauai (LIH), Oahu (HNL), Molokai (MKK), Lanai (LNY), Maui (OGG), Hawaii Island (KOA)

In case you are not asked about your detailed travel habits (because you selected a quick and simple calculation) the average of all possible flights between the six Islands is applied to calculate emissions.

Out-of-State travel emissions (Hawai'i calculators only)

Distances between airports are measured using the Google Earth Pro software. Distances (passenger miles) are used to calculate emissions using GHGP Mobile Combustion Tool V2.6. The calculation represents an average between different flight classes and are not airplane specific.

The following airports and flight routes are used within detailed calculations:

·         US west coast (SFO-HNL), US central States (DEN-HNL), US east coast (JFK-HNL), Canada (YYZ-HNL), Japan (HND-HNL), Oceania (SYD-HNL), Korea (IIA-HNL), China (PEK-HNL), Taiwan (TPE-HNL), Europe (FRA-DEN-HNL), South-east Asia (CGK-HNL), Hong-Kong (HKG-HNL), Central America (MEX-HNL), South America (RIO-DFW-HNL), South Africa (JNB-JFK-HNL), Northern Africa/Middle East (TLV-JFK-HNL), Other Asian Countries (IGA-HNL)

Within the short calculation versions, the following routes are applied to applied to calculate emissions:

·         US west coast (SFO-HNL), US central States/Canada (DEN-HNL), US east coast/Central America (JFK-HNL), Europe (FRA-DEN-HNL), Africa (JNB-JFK-HNL), South America (RIO-DFW-HNL), Japan (HND-HNL), Oceania/South Pacific (SYD-HNL), Asia (PEK-HNL)

Applies to all Calculation and Offset Tools

Vehicle emissions for gasoline, diesel and biodiesel vehicles are calculated on Emission data from the EPA Center of Corporate Climate Leadership. Emissions for electric vehicles are based on emissions produced by electricity consumption (for Hawai'i specific tools). For more information on emissions from electricity consumption, please see the energy section below.

The following fuel consumption rates are assumed within the Hawaii Visitor Emission Calculation and Offset Tool: Green Traveler (or similar) MPG45, Compact MPG35, Mid Size MPG27, Full Size MPG22, SUV/Minivan MPG17. It is assumed you travel 30 miles on every day you are in Hawai'i.

The following assumptions are applied for ground transportation emission calculations within the Hawai'i Event Emission Calculator:

Vehicle efficiency: 35 MPG; Distances per guest (both ways for events) or per day of visit: Kaua'i 30 miles, O'ahu 30 miles, Moloka'i 20 miles, Lana'i 20 miles, Maui 35 miles, Hawai'i Island 50 miles.

Hawai'i Event Emission Calculators

Accommodation related emissions are calculated using the International Tourism Partnership (ITP) Hotel Footprinting Tool V1.0, adapted to the calculators.

Hawai'i Calculation Tools

Emissions from electricity generation and other energy sources (i.e. Propane, LPG, ...) as found in the calculators are obtained from the EPA eGRID2012 as displayed in this table from the EPA Center of Corporate Climate Leadership. Within the Hawai'i Resident Emission Calculation and Offset Tool an option to offset emissions with "one click" can be found. Amount of average per captia emissions for this offset option were obtained from the US Ennergy Information Administration here. The number for each Hawai'i resident was calculated by dividing the State's entire emissions (Table 1) by the number of capita (1,427,538) (US Census). If you decide to assume average emissions for your household because you do not know your exact consumption, the number from this document (look for residential electricity use) are applied to the calculation

Global Citizen and Small Business Emission Calculation and Offset Tool

Emissions from electricity are obtained from the World Bank (CO2 emissions per capita) which are further divided by the share of emissions generated from buildings. The amount of emissions depends on the time period of the calculation.

Hawai'i calculators

Diet related emissions for Hawai'i specific calculators were obtained from "Shrink that Footprint (http://shrinkthatfootprint.com/food-carbon-footprint-diet).

Global Citizen and Small Business Emission Calculator

Diet related emissions for US and Canadian residents were obtained from "Shrink that Footprint (http://shrinkthatfootprint.com/food-carbon-footprint-diet). For European country residents, emission numbers were obtained from this study: https://www.sciencedirect.com/science/article/pii/S2211912418300361?via%3Dihub#f0005. For all other countries available in the calculator, the average emission values from the same study were applied.

We provide you with the service to compare your emissions to others to see where you stand in a larger context. The numbers displayed are obtained from the World Bank and can be found here.