Complete, transparent, consistent and accurate monitoring and reliable reporting of greenhouse gases is essential for the proper functioning of the emissions trading scheme. The scheme is to ensure compatibility of carbon dioxide emissions in each EU Member State. Rules regarding greenhouse gases monitoring and reporting are set out in Commission regulation (EU) 601/2012 of 21 June 2012 on the monitoring and reporting of greenhouse gas emissions pursuant to Directive 2003/87/EC of the European Parliament (Text with EEA relevance).

Operators and aircraft operators should perform their obligations connected with emissions monitoring and reporting following principles listed below:

1. completeness - all process and combustion emissions from all sources within the installation must be taken into account,
2. consistency, comparability and transparency – monitoring and reporting should be carried out in consistent, comparable and transparent way over time, which enable verifiers and competent authorities to reverse the method of emissions determination,
3. accuracy – it must be ensured, that the method of emissions determinations does not give results, which are systematically or knowingly inaccurate,
4. methodology reliability – reported data must not contain significant irregularities, it has to be reliable in selection and presentation of information and it must provide reliable and credible list of emissions,
5. continuous improvement – recommendations contained in verifications reports should be taken into account in subsequent monitoring and reporting activities.

The following methods are used to determine greenhouse gases emissions:

1. Calculation based approaches:

a)       standard approach (distinguishing emissions from combustion and technological processes);

It stands on calculating the emissions volume through multiplying following values:

• activity data (the amount of fuel or process source stream multiplied by the calorific value),
• emission factor,
• oxidation factor (for emissions from combustion processes) or conversion factor (for emissions from technological processes).

Calculation factors may be determined on the basis of laboratory analyses, or, depending on the tier used, by using default values, including tables containing data on net caloric values and CO₂ emissions factors for fuels used in a given year.

b)      mass balance approach, consisting in a complete balance of carob content put in the installation in the form of fuels or process inputs and leaving the installation in the form of product or waste. This method is being used in case of more complex processes, e.g. in integrated steelworks or chemistry industry plants.

2. Measurement-based approach

Greenhouse gases contained in waste gases in the installations are subject of measurement.

3. Approach, which is not based on tiers (“fall-back approach”)

This approach is bused in installations with special conditions, where the use of tiers is not technically possible or leads to irrational costs, which are incurred by the operator.

4. Combination of approaches

Possibility to combine approaches above applies to these cases, for which Annex IV of the Commission Regulation (EU) 601/2012 does not require to use specific approaches. Combination of different monitoring approaches may be only used, when there are no data gaps or emissions’ double counting.

Chosen approach must be described in monitoring plan, approved by the competent authority in a greenhouse gas emissions permit. Operator of the installation, which is covered by the EU ETS, is obliged to settle the amount of emissions each year of the accounting period, on the basis of the annual emission report, which is additionally subject to verification process carried out by the accredited verifiers. The legal act, which regulates verification process of the annual emission reports is Commission Regulation (EU) 600/2012 of 21 June 2012 on the verification of data on the accreditation of verifiers pursuant to Directive 2003/87/EC of the European Parliament and of the Council (Text with EEA relevance). During the audit compliance of the information contained in annual emission report with applicable law and, approved by greenhouse gas emissions permit, emission monitoring plan is being checked. In addition, verification is guarantee, that annual emission report contains reliable data, and the amount of carbon dioxide emissions has been determined correctly. Settling of emissions is possible only, when accredited verifier will issue positive opinion.