Carbon Offsetting FAQ’s


You might have problems using Safari browser. We suggest you use Chrome.

It has been explained to us by a techie that problems can occur when you are not using the Chrome browser.  Checking up brought me to this information @feb 2021: Chrome is used by 64.5% of global web users ! Safari comes in second at 18.1% with Firefox at 4.1% and Internet Explorer&Edge at 1.25% !

So our advice is to switch over to Chrome.

By the by, if you have any issues with the normal running of your computer, first thing to always do is to clean up your browser cache (go to your settings page). That unclogs a lot of clutter…

This issue is a follow-on of the browser one above.

Chrome has 2 “Cookies” settings– one is the general one, the other is for 3rd parties. As PET uses a licensed calculator by Carbon Footprint Ltd (UK), when you press “Calculate and Add to footprint,” the “enable cookies” message could be activated if you’re using another browser.

What to do? Make sure you’re using Chrome. If you then open your computer’s “Settings” and type “cookies” into the search box, you should see all the cookie-settings highlighted. Check that they’re all “on.”

  • The online calculators on this web site follow the methodology outlined by the UK Government, and currently using 2020 Government Conversion Factors for Company Reporting Methodology. The only exceptions to this are Country specific electricity factors:
    • Many publicly available country specific electricity emissions factors are provided for free within the calculator tool. A full list of these along with the sources is provided by Carbon Footprint Ltd in “Country Specific Electricity Factors – 2020“.
    • For countries where freely published emissions factors are not available, you can purchase IEA Emission Factors and enter them into the house / building tab of the calculator
    • Where freely available the emissions factors provided for free include both Generation and Transmission and Distribution (T&D) losses. The calculations do not, however, include the Well to Tank (WTT) Emissions associated with extraction, refining, distribution, storage of the fuels used in the power stations.


    The calculator uses emissions factors which take account of all greenhouse gases (i.e. CO2, N2O, methane etc.) released by the activities, with the results presented in units of metric tonnes of CO2 equivalent (CO2e). In most cases that means the results will be slightly higher than if calculating CO2 only. The calculations of emissions from fuels are Scope 1, meaning the direct GHG emissions from the combustion of the fuels. The calculations do not include the Well to Tank (WTT) Scope 3 Emissions associated with extraction, refining, distribution, storage and retail of the fuels.

    When calculating emissions for Wood the emissions factors for Wood Pellets is used. The calculator also assumes domestic coal is used in both the Business and Household calculators.

  • Secondary footprint tab.
    In developed countries, transportation and household energy use make up the largest component of an individual’s carbon footprint. Such emissions are included as part of an individual’s “primary” carbon footprint, representing the emissions over which an individual has direct control (what you calculate now, on this site).The remainder of an individual’s carbon footprint is called the “secondary” carbon footprint, representing carbon emissions associated with the consumption of goods and services. The secondary footprint includes carbon emissions emitted by food production. It can be used to account for diets that contain higher proportions of meat, which requires a greater amount of energy and nutrients to produce than vegetables and grains, and foods that have been transported long distances. The manufacturing and transportation of consumer goods are additional contributors to the secondary carbon footprint. For example, the carbon footprint of a bottle of water includes the CO2 or CO2 equivalent emitted during the manufacture of the bottle itself plus the amount emitted during the transportation of the bottle to the consumer.

This issue happens when, on your last visit to the calculator, you didn’t follow the offset process through right to the end. Only by submitting  payment is the  calculator brought back to zero.

(a) Go back to the calculator, to each of the calculator tabs you used and do what’s in the image ⇒
(b) then, on the final “result tab,” check you’re now happy with the total, and click on “offset.”

Sure! There are two ways to get to the carbon calculator:

(NB: though images may have been updated, the calculator steps remain the same:)


This gets you here, where you can follow an hypothetical calculation and checkout step by step:

Travel [ Image Missing from current site ]