How Does EarthEmission Account For Different Currencies?

earthemission has a variety of emission factors that use the amount of money spent on a given product or service to approximate how much GHG emissions are generated.

A table at the bottom of this page shows what currencies are supported by earthemission.

There are a few extra things you need to be aware of to get the most accurate emissions out of money-based emission factors, often called spend-based emission factors. Let's dive in to some of them.

Exchange Rates

earthemission's emission factors are generally calculated based on one currency - let's call that the source currency. This could be kg of CO2e emitted based on every US dollar spent, or kg of CO2e emitted based on every euro spent. Here, the source currency is USD or EUR respectively.

If we look at an emission factor in the search endpoint, we might get something like the following back. Notice in particular the unit and year.

{
    "activity_id": "accommodation_type_hotel_room",
    "id": "1cd2252d-10b5-4734-afca-e463110235ef",
    "name": "Hotel room",
    // Notice the year here
    "year": 2016,
    "region": "GLOBAL",
    "region_name": "Global",
    "description": "Emission intensity of supply chain (purchase of service/standard good/capital good)
     in US dollars spend on: hotel room. Factors retrieved from the Quantis+GHG Protocol Scope 3 
     Calculator for the year 2016 and apply for years beyond 2016. The same emission factor applies 
     to different types of investments in joint ventures/subsidiaries/associate companies that were 
     not captured in Scope 1 emissions.",
    "unit_type": "Money",
    // Notice here that  the unit is kg/USD
    "unit": "kg/usd"
    // More emission factor data here
}

This means that this emission factor considers what emissions are generated by one dollar of money spent in 2016.

If you use this with another currency, such as euro, earthemission will automatically use the applicable exchange rate from 2016 between EUR and USD, to determine what the correct USD amount is.

earthemission only contains exchange rates between the currencies it supports and the US Dollar. That means that if neither the source currency nor the currency you send to the earthemission API is USD, the exchange rates between the two currencies are calculated via the US Dollar exchange rates. The US dollar acts as what you would call a vehicle currency.

Inflation

Spending a US dollar on something in 2016 isn't the same as spending it in 2023 - as inflation means you can purchase less per dollar.

Where spend-based factors are updated each year by the source organisation we include the latest factors in the database as they are released. To limit the inaccuracy caused by inflation you should try to use sources that are as close to the time when you spent the money as possible, or manually adjust for inflation yourself.

At the moment earthemission offers automatic correction for inflation for EXIOBASE data within the Procurement and Travel features only.

Supported currencies

This table list all currencies that the earthemission API supports. Pass in the iso_currency_code into the API to use a specific currency.

Still got questions? Are there features related to currency that you wish earthemission supported?