The estimates from SEEG 10, cover GHG emissions in Brazil and in each of the states and federal district for the period 1970 to 2021 for all sectors, with the exception of land use change, which covers the period 1990 to 2021.
Also starting on Collection 8 there are estimates of municipal emissions covering the period 2000 to 2018.
The methodological basis of the SEEG estimates is the 4rd Brazilian Inventory of Anthropogenic Greenhouse Gas Emissions and Removals, published by MCTI in 2020.
Without the official emission inventories and respective reference reports it would not be possible to develop this Climate Observatory initiative, since the vast majority of the specific emission factors were calculated in the inventory preparation process by teams from dozens of institutions, and involving hundreds of researchers and experts.
The SEEG methodology was published in the scientific journal nature in May 2018
ELABORATION OF STEP-BY-STEP ESTIMATES
For each sector, a calculation routine was created that reproduces the inventory work for each of the reported years (eg, 1990, 1994, 2000, 2005, 2010 e 2015). Next, we look for activity data that allow us to estimate the evolution of the emissions considering the emission factors of the inventory. Dozens of public and private institutions are consulted to gain access to activity data.
In order to ensure the possibility of repeating estimates calculated by any interested party, only data obtained from public and free of charge sources are used, including data available via the internet or publicly accessible libraries.
When the activity data are not available or incomplete, several strategies are used to obtain the estimates, including the search for reference values, trend lines, correlation with data from other activities, among others.
1.Review of the IPCC methodology and inventory, including reading all reference reports prepared for the third inventory.
2.Recovery of Inventory evaluation tables to understand and test the form of application of emission factors. In the process, the sheets were redone and systems for calculating, using the 4th Inventory database, with the aim of replicating the data according to the methodology of description reference reports.
3.Activity data collection and update components for emission factors. The goal is to raise the updated information whenever possible, with the same sources of inventory, since the data are available for free.
4.Identification data gaps and defining auxiliary calculation formulas to fill the gaps. When there is gaps in the data required to use the original emission factor in the original format, auxiliary emission factors are used, usually by means of emission correlation analysis and activity level, based on this data. This phase also defines the emission allocation criteria for the states.
5.Submission and validation of methodology and data - technical seminars, conducted with experts and technicians from the Climate Observatory-member institutions, in order to review the various stages of work.
6.Review and analysis of data quality. Finally, all data are evaluated according to the quality of emission factors and activity data used. Are identified points that should be improved in future surveys, including a review of methods and data by experts from different sectors.
ALLOCATION BY STATES AND FEDERAL DISTRICT
Since version 2.0, launched in 2014, SEEG includes the allocation of emission estimates by states and Federal District. The proportion of emissions that could be allocated is increasing with each version. In SEEG 10, for the year 2021, it was possible to allocate 96,5% of the Brazilian emissions by states and Federal District. Only 3,5% of the emissions were not allocated.
Emission-generating activities (eg occurrence of deforestation, fuel consumption for transportation, industrial production, etc.) are used as a reference for the allocation of emissions by units of the Federation.
The methodological notes detail how the allocation was generated in each estimated issue item.
EQUIVALENT CARBON METRIC (GWP AND GTP)
There are two main approaches to determining the equivalent carbon: GWP (Global Warming Potential) and GTP (Global Temperature Change Potential). The first one considers the influence of the gases in the alteration of the energy balance of the Earth and, second, the influence in the increase of temperature.
Both are measured for a term of 100 years, with GWP being most commonly used.
In the database available on the OC SEEG portal, all data can also be found in CO2e and GTP by both the fith IPCC (AR5) metrics and the second, fourth and sixth IPCC reports (AR2, AR4 and AR6).
The possibility of obtaining the data in these different metrics is important to be able to make analyzes and comparisons with the 3rd Inventory (uses IPCC AR2), Brazilian INDC (uses IPCC AR5), inventories of developed countries (uses IPCC AR4).
TABLE: EQUIVALENT TO GWP AND GTP CARBON (IPCC AR2)
TABLE: EQUIVALENT TO GWP AND GTP CARBON (IPCC AR5)
The estimates of gross greenhouse gas emissions do not consider the removal of carbon dioxide by land-use change, i.e. the amount of carbon gases fixed by vegetation growth. When removals are discounted, the estimates are net emissions (emissions minus removals).
The IPCC Guidelines for National Inventories provide for the inventory of emissions and anthropogenic removals of greenhouse gases for inventory purposes. In the Brazilian inventory, in addition to considering restoration of forests, regeneration of pastures and others as carbon sinks, increases in carbon stocks in natural forests were considered as anthropic removal when located in protected areas or indigenous lands.
In fact, unprotected forests can capture CO2 if they are in the process of natural renewal, just as forests within protected areas can emit CO2 if they are in the process of being degraded. Because of the huge volume it can represent - hundreds of millions of tonnes of CO2 - this definition can create a distortion in emissions data.
Based on a conservative approach, the CB option was to prioritize the dissemination of SEEG data with gross emissions. In the query of the database on the internet are also available the estimates of removal according to the criterion used in the 3rd Brazilian inventory of emissions. It is possible to estimate net GHG emissions in Brazil.
In the SEEG estimates, the discount for emission reduction certificates from Clean Development Mechanism (CDM) projects was also not incorporated. The totals, in Brazil, between 2005 and 2014, amount to about 370 million tons of CO2e (accumulated in the period).
EMISSION FROM INTERNATIONAL MARITIME AND AIR TRANSPORT (BUNKERS)
Separate data (available for consultation in the site database) were also calculated for international maritime and air transport emissions, which should, as a rule, be reported separately as they refer to emissions with responsibility for more than one country . These data are treated in the database as bunker or international emissions.
EMISSIONS AND REMOVALS NOT CONTEMPLATED IN THE NATIONAL INVENTORY (NCI)
The National Inventory does not consider emissions and removals of carbon in the soil by agricultural practices. As these emissions and removals are essential in the Brazilian INDC account (commitments in the Paris Agreement) from the SEEG 4.0 separate calculations (available for consultation in the site database) are presented the emissions and removals due to pasture quality (degraded or well managed), application of no-till techniques (which help capture soil carbon), forest plantations and integration of livestock farming. In the database the data is identified as NCI Emissions and NCI Removals (Not Included in the Inventory).
TRANSITION MATRIX APPROACH TO LAND-USE CHANGE
Until SEEG 7.0, estimates of emissions and removals due to land use changes use deforestation data as a proxy for emissions due to the lack of annual and updated data on land use change. The MapBiomas project, another initiative of the Climate Observatory, published in 2018 annual maps of land cover and land use in Brazil from 1985 to 2017.
Based on them, the SEEG team tested calculating the GHG emissions and removals estimates based on the matrices transition factors derived from MapBiomas maps and the emission factors of the 3rd Inventory.
As of SEEG 8.0, the transition matrix method with data from MapBiomas was adopted as the standard method for emission estimates. The data with the deforestation method as a proxy continues to be used for the last years of each collection. In the case of municipalities only the standard method is used.
EMISSIONS FROM DIFFERENT SECTORAL ARRANGEMENTS
Total emissions of greenhouse gases are computed in this study in the five sectors defined by the Intergovernmental Panel on Climate Change (IPCC) guidelines for national inventories.
With the objective of obtaining a more faithful and complete representation of the representativeness of certain sectors of the economy, a pilot was organized to organize the information of the emissions for different sectors / economic activities.