qué es la huella de carbono

According to the United Nations Framework Convention on Climate Change, a carbon footprint is a change in climate attributed directly or indirectly to human activity that alters the composition of the world's atmosphere. Fortunately, each and every one of us can work together in the fight against climate change if we promote reducing our carbon footprint – a concept that has gained significant importance in recent decades, and we tell you all about it here.

A carbon footprint is an environmental indicator that represents the amount of greenhouse gases (GHGs), expressed as CO2 equivalents, that are emitted directly or indirectly as a result of a specific activity.

Even though the focus is usually on carbon dioxide, there are other gases that contribute to this greenhouse effect such as methane (CH4) and nitrous oxide (N2O).

In order to calculate the contribution of each gas, there is a parameter called the Global Warming Potential (GWP) that compares the heating power of a certain mass of this greenhouse gas with the heating power of the same amount of CO2, so that the effect of these different gases can be calculated with the same unit of measurement, called CO2 equivalent (CO2e). Therefore, the following formula is used to calculate greenhouse emissions:

GEI (t CO2e) = GEI (t gas)*GWP gas

The first step for calculating a carbon footprint is to take an inventory of gas emissions or an analysis of the life cycle depending on the type of footprint. Using this information as a base, it's possible to implement an emissions reduction strategy based on energy efficiency, cutting back on raw materials, circular economy, process improvements, etc.

How to calculate a carbon footprint

There are various guides and tools available online to calculate the carbon footprint for both individuals and organizations such as those designed by the UN, the Ministry for the Ecological Transition, the UK's Department for Environment, Food, and Rural Affairs (DEFRA); and many more. Here is how the calculation works. 

Leafs in the shape of footprints

The carbon footprint calculation is based on international standards like the GHG Protocol and ISO 14064. Emissions are calculated by multiplying the consumption data by its emission factor, depending on the fuel used, type of energy, and the intended activity. Therefore, the following formula sums up the calculation:

Carbon footprint = Activity data x Emission factor

Throughout the life cycle of any product or service that we use as individuals or organizations, we can differentiate distinct stages that require energy and generate GHG emissions: from the extraction of the raw materials, the transportation to industry where they are transformed into products, the distribution to vendors, the use by consumers, and finally the waste treatment where they may be transformed again.

In each stage, there is an organization or person capable of measuring, controlling, and managing the necessary energy and the emissions of a process (the truck driver, managers of the manufacturing process, the user of the product, etc.). These would be considered the direct emissions generated in this stage by this person or organization. The rest of the stages of the process are considered indirect emissions, since they are still associated with the activity or product, even though the person or business does not have direct control over the process of the stage.

With this in mind, emissions are classified into three scopes:

  • Scope 1 - Direct emissions: GHG emissions related to combustion from sources that are owned or controlled by the business or person, for example, boilers, vehicles, furnaces, etc.
  • Scope 2 - Indirect GHG emissions associated with energy: GHG emissions associated with the purchase of energy as electricity, steam, or compressed air, which are acquired and consumed by the business or person.
  • Scope 3 - Other indirect emissions: GHG emissions that are the result of the business or person's activity but which occur in emission sources that are not owned or controlled by the business or person. One example would be extraction and production activities of raw materials purchased by a business, the use of products sold to third parties, or waste management activities in a home or business.

How can we reduce our carbon footprint?

Without a doubt, responsible consumption is one our greatest allies, but there's even more we can do to try to cut our carbon footprint. Here are a few tips we can put into practice in our day-to-day lives to reduce it:

Local organic produce

Consume local seasonal products

By consuming proximity or zero-mile products, we help reduce the CO2 emissions derived from the refrigeration or transportation of food products. What's more, we're contributing to boosting the local economy. It's all benefits!

Energy efficiency labels

Use high energy efficiency appliances

Next-generation appliances are increasingly more sustainable and efficient. Also, checking the labeling of the appliance you're going to buy is essential to know if they're made following sustainability standards throughout the value chain. Go to our page on energy efficiency to get in the know.

A device being plugged in

Use water and electricity efficiently

We can try to save energy at home by unplugging any electronic devices we're not using. Also, if we maintain the temperature between 18ºC and 23ºC, we'll save on heating. Similarly, we should make the most of natural light during the day to save on our power bill.

We can also save hundreds of liters of water by turning off the tap while soaping up or brushing our teeth.

un padre y su hija en bicicleta, uno de los transportes más sostenibles

Use sustainable transportation whenever possible

Using public transportation or other solutions such as bicycles or electric scooters contributes to reducing the carbon footprint, while improving mobility in cities and raising the citizens' quality of life index.

Also, other sustainable mobility alternatives, such as carsharing, help reduce traffic congestion and save on private vehicle maintenance costs.

Measures companies can adopt to reduce their carbon footprint

Companies and organizations can also implement measures aimed at cutting their carbon footprint by always giving priority to actions that have a greater impact and introducing guidelines that create a carbon footprint reduction culture, both in their daily operations as well as in the management of the product life cycle.

The Repsol Campus at night

Promoting energy efficiency in all areas

Optimizing production processes and operational excellence not only involves a better use of energy and a resulting reduction in emissions, it also leads to a better maintenance of equipment, fewer breakdowns, and improved safety.

An operator checking solar panels

Leveraging renewable energy sources

Nowadays, the evolution of the energy mix enables companies to implement different types of renewable energy into their management and processes. There is a wide array of renewable energy sources to choose from based on individual needs, location, and demand.

An operator in a control room

Optimizing the supply and delivery chain

Today, we don't have to rely as much on paper and other physical material resources thanks to breakthroughs in cloud storage systems and other next-generation technology solutions that facilitate the flow of information and supplies.

Two locked hands wearing gloves with the recycling symbol in the background

Promoting the circular economy and applying its principles

The circular economy has a wide range of benefits. It protects the environment, reduces CO2 emissions, and minimizes the consumption of natural resources. It benefits the local economy by promoting production models based, for example, on inverse logistics or reusing waste. It also creates jobs and stimulates the development of a more innovative and competitive industrial model.

Repsol and its carbon footprint

At Repsol, we believe the energy sector has a defining role in the development of new products and services that favor an efficient and sustainable energy transition. We are the first company in the sector to commit to reaching net zero emissions by 2050.

Three Repsol operators

At Repsol, we view decarbonization as an opportunity for developing more profitable businesses in order to continue growing and become the multi-energy company that society needs in this decade to sustainably meet all its energy needs. To achieve this, we've set new, more demanding business plans for our strategy, activity, and investments that are aligned with meeting the climate change objectives of the Paris Agreement to prevent an average global temperature increase of more than 2ºC.

We calculate and report the carbon footprint of our organization, where 99% of our direct and indirect emissions are verified according to the EU ETS or ISO 14064; and we were favorably assessed by the Climate Disclosure Project (CDP, a world database used by investors) with an A- rating for the second consecutive year, placing in the Leadership tier and surpassing the average in the O&G sector.

We have believed since 1992 that energy efficiency projects are key in reducing our carbon footprint in the stages where we manage operations and have set demanding reduction goals in our strategic plans. Our current plan includes investing more than 400 million euros until 2025 to reduce 800,000 tonnes of CO2 and to lay the foundation for transforming our industrial centers into net zero emissions facilities.

In addition, we calculate the carbon footprint of our products. We analyze the impact throughout the different stages of the product's life cycle following the ISO 14067 methodology, a strict international standard that validates the rigor of our work.

In terms of our customers' carbon footprint reduction, we aim to produce 1.3 million tonnes of sustainable biofuels in 2025 and more than 2 million in 2030, committing to a business of efficient products centered on circular economy and the production of advanced biofuels.

A smartphone with the Waylet app

Repsol can help you reduce your carbon footprint

Recently, we kickstarted a voluntary initiative to neutralize emissions called the Net Zero Emissions Commitment, which we manage through our innovative application Waylet and Vivit. Every time a customer refuels at one of our more than 3,400 service stations and pays with the Waylet application, they will have the option to offset 100% of the CO2 emissions from that fuel consumption through collaboration in reforestation projects.