The emission estimates by SEEG are developed based on the data sources indicated and the methodologies presented in the Brazilian Inventories of Greenhouse Gas Emissions and Removals, organized by the Ministry of Science and Technology. In general, the applicable emission factors are found in these inventories. The activity data necessary for emission estimates are sourced from dozens of public and private institutions. To ensure the possibility of reproducing the estimates calculated by any interested party, preferably publicly available and free data are used, including data available through the internet or in libraries with public access. When activity data are not found available or are incomplete, alternatives to inventory methods are used, such as the use of surrogate variables, trend projections, application of functions with correlated variables, among others.

SEEG presents estimates of direct greenhouse gas emissions – carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), and fluorinated gases (HFCs, CFs, and SF6) – and indirect emissions – carbon monoxide (CO), non-methane volatile organic compounds (NMVOCs), and nitrogen oxides (NOx). Emissions are also presented in terms of carbon dioxide equivalent (CO2e) using Global Warming Potential (GWP) and Global Temperature Change Potential (GTP) over a 100-year horizon, based on the metrics of the second, fourth, fifth, and sixth assessment reports of the IPCC (AR2, AR4, AR5, and AR6).

The estimates of gross greenhouse gas emissions do not include the removal of carbon dioxide by changes in land use, i.e., the amount of carbon gases fixed by vegetation growth. By subtracting these removals, the estimates become net emissions (emissions minus removals). IPCC guidelines for national inventories provide for the accounting, for inventory purposes, of anthropogenic emissions and removals of greenhouse gases. In the Brazilian inventory, in addition to considering forest restoration and pasture regeneration as carbon sinks, increases in carbon stocks in natural forests located in conservation units or indigenous lands are considered as anthropogenic removals. It is important to note that unprotected forests may capture CO2 through natural renewal processes, while forests within protected areas may emit CO2 if they are undergoing degradation. Given the significant quantity involved – hundreds of millions of tons of CO2 – this definition can distort emission data. Adopting a conservative approach, Observatório do Clima chose to prioritize the disclosure of SEEG data with gross emissions. In the online database, estimates of removals according to the criteria of the 3rd Brazilian emissions inventory are also available, allowing for the estimation of net greenhouse gas emissions in Brazil. Additionally, SEEG estimates did not incorporate deductions for emission reduction certificates from Clean Development Mechanism (CDM) projects. The totals in Brazil for the period from 2005 to 2014 amount to around 370 million tons of CO2e (accumulated over the period).

Emissions from international maritime and aviation transport are reported separately from other emissions (gross) because they are emissions with responsibility shared by more than one country. These emissions are classified as ‘bunker’.

The National Inventory does not consider carbon emissions and removals from soil due to agricultural practices or emissions from wildfires in native vegetation areas not associated with deforestation. These emissions and removals can be significant and play crucial roles in climate commitments and targets, such as an NDC. Therefore, starting from the fourth SEEG collection, these emissions and removals have been presented under the Agriculture sector (separately from the emissions classified as “NCI” – not counted in the Inventory). NCI includes emissions and removals due to pasture quality (degraded or well-managed), the application of no-till farming techniques (which help capture carbon in the soil), forest plantations, and crop-livestock integration. Meanwhile, emissions from wildfires not associated with deforestation represent net emissions caused by fires in native vegetation and have been reported under the Land Use Change sector since the sixth SEEG collection, with continuous improvements in the estimates.

Until the seventh SEEG collection, published in 2019, estimates of greenhouse gas emissions and removals from land use change used deforestation as a proxy variable due to the absence of annual and updated data on land use change in Brazil. The MapBiomas project published its first annual maps of land cover and land use in Brazil from 1985 to 2017 in 2018. Thus, SEEG presented the first estimates of emissions and removals based on transition matrices derived from MapBiomas maps and emission factors from the 3rd Inventory. From the eighth SEEG collection, published in 2020, the standard method of SEEG was changed to consider transition matrices with MapBiomas data.

The SEEG presents estimates of emissions and removals by states and municipalities. In the Land Use Change, Agriculture, and Waste sectors, most of the emissions and removals are already calculated by state and municipality, as activity data are disaggregated by states and municipalities. In the Energy and Industrial Processes and Product Use sectors, this is not always the case, and emissions are allocated using distribution factors derived from surrogate or correlated variables disaggregated at the state and municipal levels.

In the effort to allocate estimates of greenhouse gas emissions to municipalities, the SEEG team encountered several obstacles in the availability, form, and quality of necessary data. In cases where data regarding local sectoral economic activities are not open to public or private organizations or not published at the municipal disaggregation level, efforts were made to allocate federal or state values ​​to the municipal level through the relationship of national data with linked variables (proxy). Click here to access the document where we list the gaps found in the availability of municipal data, according to the sector, the importance of missing data, SEEG’s actions in attempting to overcome these obstacles, and recommendations to guide the entities involved in the task of making this data available in a facilitated manner.

The calculator developed in partnership between SEEG and G1 Portal offers an innovative approach to estimate the individual responsibility for Brazil’s greenhouse gas emissions. The tool covers all levels of emissions in the country, attributing them to individuals according to their main determinants, such as the consumption of specific products. Although some classes of emissions cannot be directly linked to a single factor, they are distributed proportionally based on the overall consumption index related to per capita family income. Click here to access the complete methodological note.