The carbon footprint: how it is calculated, what it means and how it can be reduced

In a world increasingly affected by climate change, understanding how our everyday actions contribute to its worsening has become essential. The carbon footprint is an environmental indicator that measures the total amount of greenhouse gasesWhile the concentration of carbon dioxide (CO2) in the atmosphere has been steadily and rapidly increasing in recent decades, in May 2025, CO2 surpassed 43...
Read more (GHGs) we emit directly or indirectly into the atmosphere. From switching on a light to taking a flight or simply preparing a meal, every activity we undertake leaves an “invisible mark” on the atmosphere that accumulates and intensifies global warming. In this article, we will examine what the carbon footprint is, why it is so important to measure and control it in our daily lives, as well as in the day-to-day operations of our cities and businesses. We will explore how it is possible to quantify our carbon footprint and the legal measures in place to control those caused by any personal or industrial activity. Most importantly, effective control begins with the real-time measurement of the emissions that generate the carbon footprint. Hopefully, with this article, we can already begin to erase that carbon footprint.

What is the carbon footprint?

Definition and scope

The carbon footprint is an environmental indicator that measures the total amount of greenhouse gases (GHGs) emitted into the atmosphere as a direct or indirect consequence of the activities of an individual, organisation, product, or event. Although it is referred to as the “carbon footprint”, this concept encompasses several chemical compounds, with carbon dioxide (CO₂)Carbon dioxide (CO2) is a gas that occurs naturally in the atmosphere and plays a crucial role in the life processes of the planet. This gas, also known as...
Read more being the main protagonist. This gas, released in large quantities through the burning of fossil fuels and other industrial and domestic processes, is the primary driver of planetary overheating. Methane (CH₄)Methane, known chemically as CH₄, is a gas that is harmful to the atmosphere and to living beings because it has a high heat-trapping capacity. For this ...
Read more and nitrous oxide (N₂O) are also included, and together they are the main contributors to global warming that is accelerating climate change. Our daily lives—driving, doing the laundry, charging a mobile phone, or consuming products—generate a constant trail of emissions into the atmosphere. In fact, the global carbon footprint has increased elevenfold since 1961, reflecting an unsustainable development model.

From driving a vehicle, running the washing machine, or consuming food, everything we do generates a trail of gases, with CO₂ emissions standing out as they accumulate in the atmosphere and define our personal carbon footprint.

Understanding and calculating our carbon footprint not only raises our awareness of the problem, but also enables us to take action to reduce it. Every small decision matters in the fight for a cleaner and more liveable future.

Why it matters to businesses and cities

The carbon footprint has become a key indicator for businesses and cities seeking to responsibly manage their environmental impact. Measuring it not only enables the reduction of emissions, but also serves as a strategic tool in the mitigation of climate change.

Businesses

For business activities, reducing the carbon footprint means enhancing sustainability as a significant competitive advantage within their market strategy. Furthermore, understanding and managing their carbon footprint offers multiple benefits:

• Regulatory compliance: environmental regulations are becoming increasingly stringent, and measuring and reporting greenhouse gas (GHG) emissions is already a requirement in many business sectors.
• Reputation and competitiveness: consumers, investors, and partners are placing greater value on environmental commitment. Being a sustainable company enhances brand image and opens up new business opportunities.
• Access to finance and markets: there are various financial products such as funds, grants, and emissions trading schemes that reward innovation and the reduction of atmospheric emissionsAtmospheric emissions are pollutants emitted into the air, mainly as a result of human activities such as industry, transport by combustion vehicles and en...
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• Efficiency and savings: identifying emission sources enables the optimisation of industrial processes, reduction of energy consumption, and consequently, lower operational costs.
• Alignment with the SDGs: contributing to the United Nations Sustainable Development Goals and global climate commitments strengthens the company’s role as an agent of social change.

Cities

In the urban context, calculating the carbon footprint is essential for designing effective public policies that support planning for a sustainable future. This is achieved by:

• Prioritising key projects: focusing efforts on areas such as transport, energy, waste, or water to generate environmental, social, and economic benefits.
• Access to international funding: facilitating the acquisition of financial resources to implement climate change mitigation and adaptation initiatives.
• Civic participation: involving governments, businesses, and citizens in collective solutions to achieve more resilient and sustainable cities.
• Compliance with climate commitments: to meet targets set in international agreements such as the Paris Agreement or the 2030 Agenda.

Measuring the carbon footprint is a step towards climate neutrality supported by technological innovation. This ensures compliance with the regulatory commitment established by Royal Decree 214/2025, a key regulation in Spain for the registration of the carbon footprint, which harmonises GHG obligations and, at the same time, makes them more transparent. Its implementation encourages reduction, offsetting, and absorption projects with a comprehensive approach, promoting innovation and sustainability. In compliance with this Royal Decree for carbon footprint registration, digital monitoring provides real-time data that ensures regulatory compliance and drives operational sustainability. It also offers a significant competitive advantage: beyond mere obligation, companies that anticipate and communicate their achievements in footprint reduction strengthen their reputation and resilience in an increasingly demanding market.

Consequently, the carbon footprint is not just an environmental metric: it is a strategic tool to transform the way we produce, consume, and live. Both businesses and cities that commit to its measurement and reduction are taking a decisive step towards a more sustainable, competitive, and responsible social model.

From the extraction of raw materials to the final disposal of a product, every stage involves the release of CO₂ into the atmosphere.

How the carbon footprint is calculated

The calculation of the carbon footprint involves quantifying the total amount of greenhouse gases (GHGs) emitted directly or indirectly by an organisation, product, event, or individual, expressed in tonnes of CO₂ equivalent. The process follows internationally recognised methodologies, such as the GHG Protocol or the ISO 14064 standard, and is based on the principles of relevance, consistency, accuracy, and transparency; these are fundamental to ensure that results are reliable, comparable, and useful for decision-making.

Basically, it follows the formula:

Carbon footprint = activity data (amount of resource consumed or activity performed) x emission factor (amount of GHGs emitted per unit of activity data).

In addition, this calculation must take into account several scopes (three levels) depending on whether emissions are direct or indirect and their source.

To estimate the scopes, it is necessary to rely on official and specific data from each emission source:

Greenhouse gas inventory

The GHG inventory is the systematic record of all sources and sinks of emissions within the defined boundaries of the organisation or activity. It includes the quantification and classification of emissions according to the aforementioned scopes. This inventory is essential for identifying the main sources of emissions and establishing reduction strategies.

Use of CO₂ sensors for carbon footprint calculation

CO₂ sensors enable real-time monitoring of carbon dioxide concentrations both in indoor spaces and at specific emission sources, such as chimneys or industrial processes. This information can be used as activity data for the direct calculation of emissions, especially in facilities where CO₂ is the main greenhouse gas released.

The incorporation of these environmental sensors significantly improves the accuracy and traceability of data, facilitating continuous monitoring and reliable verification of emissions. This real-time measurement capability is key to optimising environmental management and complying with regulatory emission control requirements.

Furthermore, knowing our carbon footprint allows us to compare it with that of other individuals, organisations, or countries, which can be a powerful driver of change and awareness of the importance of reducing it.

Carbon emissions management platforms and software

There are numerous platforms and digital tools that automate the calculation, recording, and reporting of the carbon footprint. These solutions allow you to:

• Integrate energy consumption data, transport, and production processes.
• Automatically apply updated emission factors.
• Generate reports in accordance with international standards (GHG Protocol, ISO 14064).
• Visualise trends and simulate reduction scenarios.

Examples of these tools include official calculators from public bodies, corporate software, and cloud platforms, which simplify management and compliance with climate commitments.

In summary, the calculation of the carbon footprint combines rigorous data collection, the application of recognised emission factors, and the support of digital measurement and management technologies to obtain reliable results that are useful for environmental decision-making.

Real-time emissions monitoring

Real-time emissions monitoring has become an essential tool for managing and mitigating the environmental impact of industrial, urban, and agricultural activities. Thanks to technological advances, it is now possible to obtain precise and continuous data on the presence of GHGs and other pollutants, which facilitates informed decision-making, regulatory compliance, and the improvement of operational sustainability.

Its precise suitability for calculating the carbon footprint is due to:

Kunak environmental sensors for GHG monitoring

The environmental sensors developed by Kunak stand out for their high precision and sensitivity in detecting key gases such as methane (CH₄) and carbon dioxide (CO₂), the main drivers of global warming. Their main features include:

• Real-time measurement of very low GHG concentrations, with sensitivity down to 2 ppm for methane.
• Multipoint monitoring through networks of sensors distributed around industrial perimeters, urban areas, or agricultural zones.
• Operational versatility thanks to interchangeable cartridges that allow the measurement of different gases and particles depending on the application.
• Autonomy and robustness by operating with solar power, wireless connectivity, and a rugged design for remote locations or areas without electrical infrastructure.
• Advanced calibration that ensures data reliability even under variable environmental conditions.

Integration with emissions management platforms

The integration of Kunak sensors with their digital environmental management platforms enables more effective and automated supervision:

• Centralised visualisation of real-time data from multiple locations.
• Automatic alerts when critical thresholds defined by regulations or users are exceeded.
• Generation of technical reports ready to be submitted to regulatory authorities or stakeholders.
• Compatibility with industrial systems and smart city platforms, facilitating decision-making and rapid response to incidents.
• Automation of actions through specific plugins that enable predetermined responses to critical events.

Advantages of noiseImagine waking up every morning at 5:00 a.m. to the relentless roar of a motorway just metres from your window. Experiencing such high-intensity noise is n...
Read more management software applied to CO₂

The use of noise management technologies (understood as the control of unwanted signal interference or fluctuations) in CO₂ emissions analysis offers significant advantages:

• Reduction of interference: through advanced signal processing algorithms, originally designed to minimise noise in acoustic measurement, which improve the accuracy of gas detection such as CO₂ and enhance the reliability and precision of the data.
• More stable and reliable readings: noise management enables more accurate measurements, even in complex industrial environments with high variability.
• Optimised calibration: expertise in noise control allows for more precise and continuous sensor calibration, reducing maintenance needs due to lower drift.
• Integrated environmental vision: simultaneous monitoring of noise and CO₂ provides a more comprehensive view of the environment, useful for assessing combined impacts and improving environmental quality.

Taken together, real-time monitoring, the integration of advanced sensors, and the use of specialised software constitute a robust and efficient solution for the control and reduction of GHG emissions.

Strategies to reduce the carbon footprint

Reducing the carbon footprint has become a strategic priority for companies and organisations seeking to move towards more sustainable, efficient, and resilient models. To achieve this, it is essential to implement a set of technical and management strategies aimed at minimising GHG emissions at every stage of the value chain.

These actions include:

Optimisation of industrial processes

Optimising industrial processes involves reviewing and improving every production stage to reduce energy and raw material consumption, minimise waste, and avoid unnecessary emissions. This can be achieved through automation, digitalisation of processes, heat recovery, predictive maintenance, and modernisation of equipment. The implementation of energy efficiency systems in industry can lead to significant energy and emissions savings, as well as improving business competitiveness and reducing operating costs.

Energy substitution and efficiency

Energy substitution involves replacing conventional energy sources, such as coal or natural gas, with renewables (solar, wind, biomass, etc.), which drastically reduces carbon emissions. At the same time, energy efficiency is enhanced through the use of low-consumption equipment, LED lighting, improvements in thermal insulation of buildings, and the procurement of 100% renewable energy. These actions reduce the carbon footprint while also generating long-term economic savings and improving corporate image.

Use of data for continuous improvement

Air monitoring and the use of data provided are essential for continuous improvement in emissions reduction. Implementing measurement and control systems makes it possible to identify the main sources of GHGs, set realistic targets, assess the impact of actions taken, and identify new optimisation opportunities. Regular data analysis facilitates informed decision-making and strategy adaptation, ensuring steady progress towards sustainability.

In summary, adopting this comprehensive approach not only helps to mitigate climate change, but also improves competitiveness, reduces operating costs, and strengthens corporate reputation.

Frequently asked questions about the carbon footprint

What is the difference between carbon footprint and carbon neutrality?

The carbon footprint is the total amount of greenhouse gas (GHG) emissions, expressed in tonnes of CO₂ equivalent, that is generated directly or indirectly by an activity, product, organisation, or individual. In contrast, carbon neutrality is the state in which net GHG emissions are equal to zero; this is achieved by reducing emissions and offsetting the remainder through absorption or mitigation projects, such as reforestation or the use of renewable energy.

In summary, the carbon footprint measures environmental impact while being carbon neutral means having fully offset our carbon footprint.

Which CO₂ sensors do I need for my company?

The choice of the appropriate CO₂ sensor depends on the type of business activity, the environment where the measurement is to be taken, and the environmental control objectives to be met. The main types are:

• NDIR sensors (Non-Dispersive Infrared): ideal for offices, industries, and enclosed spaces. They offer high accuracy, stability, and low maintenance.
• High-sensitivity sensors: recommended for industrial processes or point emissions where it is necessary to detect very low concentrations of pollutants.
• Multiparametric sensors: allow the measurement of CO₂ along with other pollutants (CH₄, NO₂, PM), useful for a comprehensive environmental overview.
• Autonomous and networked sensors: operate with solar power and wireless connectivity; ideal for remote installations or locations without electrical infrastructure.

How is the carbon footprint reported according to ISO 14064?

The carbon footprint according to the ISO 14064 standard is reported following a technical and standardised process that ensures transparency, accuracy, and comparability of results. This international standard sets out the principles and requirements for the quantification, monitoring, reporting, and verification of greenhouse gas (GHG) emissions from an organisation or product.

The process consists of the following steps:

• Definition of boundaries and scopes: first, the boundaries of facilities, activities, and processes are identified, and then the scope (three levels) of emissions is determined, whether they are direct emissions (e.g. combustion in owned sources), indirect emissions (e.g. electricity consumption), or other indirect emissions (travel, transport, supply chains).
• Data collection and quantification: activity data are collected and recognised emission factors are applied to calculate the tonnes of CO₂ equivalent emitted by each source.
• Preparation of the GHG inventory: all identified emission sources, calculation methods, emission factors used, and results obtained are documented. This inventory must be consistent, transparent, and verifiable.
• Preparation of the emissions report, which must include:
  • Description of the organisation and inventory boundaries.
  • Methodology used.
  • Emission results by scope and source.
  • Uncertainties, exclusions, and justification.
  • Reduction actions implemented or planned.
• Verification and validation by an external and independent verifier who confirms that the report complies with the standard’s requirements.
• Submission and communication of the verified report to the competent authority, official registries, or stakeholders to demonstrate the company’s commitment to environmental management and transparency.

What is the cost of implementing a monitoring system?

The cost of implementing a monitoring system to control the carbon footprint varies significantly depending on the size of the organisation, the scope of the monitoring system to be implemented, the level of automation required, and the technology selected. The main investments should include the acquisition of specialised software, installation of an environmental sensor network, expert consultancy, training, technological infrastructure, and maintenance costs. These costs are offset by the long-term savings achieved by complying with current regulations and improving corporate reputation.

Can I integrate Kunak data into my environmental ERP?

Yes, you can integrate data from Kunak sensors into your environmental ERP easily and efficiently. Kunak offers various technical solutions designed to facilitate interoperability with corporate environmental management systems:

• REST API: allows direct integration of data generated by their sensors into any platform, environmental ERP, SCADA, or website. This API uses standard formats such as JSON, making it easy to extract, manage, and visualise information in real time or historically within your own system.
• Export and compatibility: data can be exported in different formats and are ready to be integrated into environmental management systems, enabling process automation, report generation, and feeding customised dashboards.
• Kunak AIR Cloud platform: in addition to direct integration, you can manage and analyse data from the Kunak AIR Cloud web platform, which also enables export and information exchange with other business systems via the API.

In summary, Kunak’s open architecture and integration tools allow you to connect their sensors with any environmental ERP, facilitating advanced air qualityAir quality refers to the state of the air we breathe and its composition in terms of pollutants present in the atmosphere. It is considered good when poll...
Read more management and emissions control in your organisation.

Every action counts in the fight against climate change to achieve the transition towards a low- or zero-carbon economy.

A global commitment

Reducing the carbon footprint has become a central pillar of climate action worldwide, reflecting the commitment of governments, businesses, and citizens to sustainability and the protection of the planet. This effort is embodied in an increasingly demanding regulatory framework, which requires companies and organisations to calculate, reduce, and register their carbon footprint, as well as to develop concrete reduction plans and report transparently.

The carbon footprint is much more than a technical indicator: it is a management tool, a symbol of responsibility, and an opportunity to transform production and consumption models. Every action counts, from optimising industrial processes to adopting renewable energy and integrating advanced monitoring technologies. The challenge is global, but the response is collective and begins with every organisation, city, and individual.

With everyone’s cooperation and commitment, we can achieve true sustainability that preserves life on our planet.