General change of footprint

Get personalised tips on how to reduce your climate footprint based on your habits and household data.

All inputs, outputs and defaults can be seen in the Change general technical API docs.


All inputs to this endpoint are optional, with default values defined in case of missing input.

This endpoint receives as input:

  • a dataset (country) to base calculations on (defaults to Norway)
  • the date for which the footprint should be computed (defaults to today’s date)
  • language  of the outputted text (defaults to Norwegian)
  • ordering of tips (defaults to amount of kgCO2e saved), choose between:
    • by amount of kg CO2e saved (descending order)
    • by points earned (descending order)
    • by money saved (descending order)
    • by financial cost (ascending order)
    • by time required (ascending order)
    • by perceived social difficulty (ascending order)
    • Randomised
  • returnLegacyTipId: this is an id used exclusively for internal purposes within Ducky and will not provide any value/insights for external users (defaults to false)
  • ignoreZeroOrNegativeTips - a parameter that decides whether or not tips with zero or negative emission savings should be returned (defaults to true, which means that only tips with a positive emission saving should be outputted)
  • filtering criteria for tips (see more detailed description in the Description of filtering criteria section below)
    • Tags
    • financial cost to perform the tip
    • module 
    • points
    • social difficulty
    • time required to perform the tip
    • id
  • a list of habits and a household description. Available habits are  as outlined in the Calculator endpoints, used to calculate the savings for an individual with those specific habits. If no habits or household info are provided, the calculation will assume default answers which match an average person from the data source specified.

Description of filtering criteria

The filtering criteria are a way for the user to limit the outputted list of tips only to the ones that are of specific interest to them.

Filtering by module enables the user to view tips belonging to a specific sector, e.g. just delivering transport tips. Available modules are: energy, food and drink, goods and services, transport, public or global

Activities are tagged according to topic. Available tags are consumption, energy, food, food_waste, plastic, sustainable_food, transport, tutorial, microplastics, overuse, plastic_on_the_go, handprint, textile, daily_habit or work. Use this filtering parameter to receive tips only on this topic.

Filtering by points allows the user to select tips based on its level of impact. The handprint is quantified using a points scale with the following options: individual (5 points, eg. biking to work instead of using the car), social (10 points, eg. convince your friend to buy second-hand instead of buying new) and community impact (15 points, eg. talking to your local politician to implement a car tax in your neighbourhood). A high point score means a large indirect impact - in addition to lowering your own footprint, you are influencing others to reduce theirs.

Each tip also has a set of investment attributes which describe the different types of costs associated with performing the tip. Filtering on these attributes allows a user to exclusively receive tips that align with their desired commitment and experience level.

The financial cost of performing each tip is based on the average price of performing the tip, converted to an order of magnitude scale with the following options:  less than 10€, 10- 100€, 100-1000€, 1000–10 000€, greater than 10 000€.

The time required is the approximate time taken from initiating a tip to its completion (eg. if a user decides to move to a new house, this would be a project that takes months - the time required to complete the tip would then be months, even if they are not spending all their time moving). The time investment is split into the following options: minutes, hours, days and months.

The social difficulty is based on the perceived difficulty of performing a tip, taking into consideration that the participant is a member of a society that sets expectations and limitations to how they conduct their life. The social difficulty is split into following options: socially acceptable (easy to do), inconvenient (moderately easy to do) and breaks social norms (requires effort to do). For example the tip “avoid over-purchasing food” would be classified as socially acceptable since it is rather easy to perform and does not require any involvement of members of the participant’s community outside of the household. The tip “walk to work instead of taking the car”, however, would be classified as inconvenient since it involves a bit more effort.


This endpoint returns a list of actions the user can undertake in order to lower their CO2e emissions by practising more sustainable behaviour. For each tip, the following attributes are displayed:

  • title: name of the tip
  • description: a short summary describing the tip
  • id: unique identifier assigned to the tip
  • subCategory: a descriptor used to categorise tips.  Will not be of interest to most users, but is used internally by Ducky 
  • module: the sector the tip belongs to (food and drink, transport, energy,goods and services, public and global)
  • tags: labels used to categorise tips, including which SDG they contribute to
  • indicators: metrics used to evaluate the impact of the tip
    • milligrams of CO2e saved (per day unless otherwise specified)

    • points

    • money saved

  • investments: costs of performing the tip
    • financial cost: a value in the range 0-10, 10-100, 100-1000, 1000-10 000 or 10 000 +, in €.
    • social difficulty: can be socially acceptable, inconvenient or norm breaking
    • time required: order of magnitude, one of: minutes, hours, days, or months
  • group: used to batch similar tips
  • groupOverrides: used to highlight tips which are incompatible with each other. (the tip “I bought used clothes today” has the group “bought_something” and overrides the group “bought_nothing”, because it is not possible to buy something and buy nothing)
  • imageURLs: the link to the image file of  the icon representing the activity, in different sizes and formats


Each tip is an action the user can perform to lower their climate footprint. 

The majority of tips are calculated by first calculating the current footprint of the person given their input habits, then calculating the footprint of the same person with their habits changed accordingly,  so as to reflect the lifestyle change of the tip. The difference between the two footprints is the CO2e savings.  The footprint is calculated using the same logic as in the Calculate endpoints (see documentation here). 

The effect of some tips is not quantifiable by the Ducky habit calculator, in which case relevant life cycle assessment and habit data is used to estimate the effect of the tip.

Tips that require investing in an expensive installation

Some tips require investing in an expensive installation (like buying a heat pump, installing solar panels, or getting better-insulated windows). When calculating the CO2e savings of such tips, we assume that the new installation replaces the current one. For e.g., if a user has an existing solar PV installation, the “install solar PV” tip would output the CO2e savings for the user if they replace their old solar PV installation with the one recommended by the tip.