We aim to provide the most accurate information to give you the best possible understanding of the carbon footprint. We thank you for your patience while we continue to assimilate new data into our calculations that will increase understanding on the energy used to bring us the goods and services. If you have any questions, issues or feedback, we would love to hear from you at feedback@greenswrm.com
Exclusions
Without further investigation, we have assessed that the energy used for the following will be infinitely small and consistent when comparing across a range of products or vehicles.
- The energy used to build infrastructure of the processing plants, power stations, factories, road / rail networks, wholesale / retail buildings, recycling / disposable plants are discarded.
- Energy used for services like training, personnel movements, marketing / advertising are discarded.
Resources
The energy used in resource acquisition is broken down by the type and size of product.
The type of product will give us a basis for how much non-renewable resource is contained within the product. The size governs how much of the resource was used.
The country of manufacture determines the most likely location the natural resources are sourced from and provides us with an efficiency rating based on this location.
Manufacturing
We are using the breakdown of the type of energy production by country between renewable and non-renewable resources. The average plant size and daily production is used for each country against the global index for manufacturing efficiency (sources: International Energy Agency, American Council for an Energy Efficient Economy).
Product
We use the type of product and size (or weight) to determine the product factor in our calculation. The materials used to produce goods gives us a significant indication on how much energy is consumed during manufacturing. Products with exotic materials use far more energy than basic, natural products to manufacture.
Manufacturing Origin
Our best attempts to find a suitable resource to provide all products’ manufacturing origin have not been reliable. Companies are generally required to show where the product is made on their packaging labels. We hope that with your support we can build up our own database of products origin.
It is valuable to the economy to have products made where they are purchased, but it is not always the case that this will use less energy. With infrastructure in place for larger overseas factories, a product can have a reduced energy footprint by being manufactured in a centralised location and using the best available shipping resources for distribution.
Distribution
Sea
All shipping routes have been calculated using the most common route between countries (source: Norie’s Nautical tables & www.marinetraffic.com voyage planner). We cannot account for energy waste due to delays to individual shipments (such as weather, docking delays). The shipping speed we use is based on an optimised fuel consumption of 18 knots (which is currently the most commonly used speed for cargo vessels) but does not account for any faster steaming that is occasionally used for schedule optimization.
Road
All road transport is calculated using an average road distance between two points. We cannot account for energy wastage due to traffic, construction, alternate routing or any other dynamic variables. We currently do not account for any energy associated with further shipping requirements such as refrigeration.
Rail
All rail routes are calculated on the shortest distance between internodal points. It does not include alternate routes used by different carriers that optimise cargo distribution.
Wholesale
The wholesale distribution network has been calculated based on the distributor, location of retail store, type and origin of product. It has been assumed that the same shipping method has been used for all retailers.
Personal Transport
Passenger Vehicles
We have used the MPG (Miles per Gallon) for passenger vehicles provided by the EPA (Environment Protection Agency). The energy consumption calculation is based on the distance you travel and the MPG of your vehicle.
All vehicles included are between 1984 and future releases up to 2019.
Type, Size and Weight of vehicles are used to calculate the Life Cycle energy as well as the manufacturing country of the car (source: vehicle websites, https://www.nhtsa.gov/part-583-american-automobile-labeling-act-reports).
Disposal
Disposal of products is calculated from the average distance of garbage collection routes per load per state. No allowance has been made if the truck does not contain full loads.
The portion of recycled waste is removed from the total disposal amount. All processes involved in reusing the recycled material are considered as included in the new product.
Grocery
Average by State
Shoppers purchase 13 individual grocery items per week (source: Catalina report) which is used to calculate the average daily grocery energy consumption.
Retailers
We have broken down the energy used for retail stores by state. The energy is based on the average shelf life and space taken up within the store against the average size of retail stores in that state.
Perishables (produce and farm)
The footprint is calculated based on seasonal information. Freight is based on the seasonal information for adjacent states and countries. Calculations are based on Food Carbon Index Results, FAO and USDA data.
Household and Personal Devices
All information is calculated from information supplies by manufacturers and verified by Energy Star (US DoE).
Speeds
Walking speed calculated at 3.1 miles per hour, 100 kcal per mile
Bicycle speed calculated as 9.6 miles per hour, 50 kcal per mile
Subway, Train, Bus and Taxi speeds are calculated from the state averages.
(Sources: Federal Transit Administration U.S. Department of Transportation, Bureau of Transportation Statistics, National Transit Database, Federal Highway Administration, American Public Transportation Association, United Nations: Department of Economic and Social Affairs, Organisation for Economic Co-operation and Development)
Appendix
Kilowatt hours: Is equivalent to 3.6 MegaJoules (transmitted at a constant rate) over 1 hr
British Thermal Units: the amount of heat required to raise the temperature of one pound of water by one degree Fahrenheit
CO2 Equivalent: Unit representing the equivalent amount of CO2 that is released into the atmosphere.
Burritos: Based on an average size burrito of 860 Calories (kcal) or 3600 Joules
Bees: Based on an average hive of 50,000 bees it is the equivalent energy of the nectar that is collected by the honey bee.