In recent months, we have seen announcements by Big Tech like Apple, Microsoft aiming to be carbon-negative by 2030. What exactly is this carbon footprint? And how do we measure it?

Carbon footprint is the amount of carbon dioxide released into the atmosphere as a result of the activities of a particular individual, organization, or community.

What if I release methane or any other gas instead of CO2?

The impact of the released gas is measured in GWP (Global warming potential). Each greenhouse gas (GHG) has a different global warming potential (GWP) and persists for a different length of time in the atmosphere.

As per the above table, if I release 1kg of Methane into the atmosphere, it is equivalent to 25kg of CO2.

The common doubt we have is “I don’t own an industry which causes emissions. And my job is in no way related to chemicals. Do I still emit emissions?”

There are three agreed ‘scopes’ for considering and measuring carbon emissions:

• Scope 1 measures the direct impact of your organisation, or emissions that are created by assets that your organisation owns. This includes things like company vehicles and fuel use on-site.
• Scope 2 measures carbon you don’t create but consume, which includes electricity usage and natural resources.
• Scope 3 measures the impact of your employees and contractors and the carbon they create. This includes: air travel, waste, contractor-owned vehicles, outsourced activities, or commuting.

The emissions vary from country/ region depending on the source.

For example, you want to measure the emissions from your electricity usage. If your electricity is from coal-dominant, the emission is different compared to solar-dominant electricity.

The above table gives the carbon emissions of electricity usage in India, the average value being 0.82 tonnes CO2/MWh or 0.82kg CO2/kWh.

Let’s say you use 1000 units of electricity per month and all the electricity being sourced is from the main grid. So, your annual usage is 12000 units. This emission comes under “Scope 2” and the annual carbon emission = 12000*0.82 = 9840kg CO2/yr.

You can also refer to our earlier blogs on Covid19 or Bitcoins in case you would like to know more about how carbon footprint is being calculated in different scenarios.