The aviation sector is responsible of the 2% of Global Greenhouse Emissions (CO2) and the sector is committed to reduce, by 2050, its net CO2 emissions to 50% of what they were in 2005. Considering that in 2037 the number of passengers will be doubled, at constant 3,7% anual growth, the aviation sector must optimize its fuel efficiency by 2% every year to achieve the goal by: better air operations (air navigation procedures), better techonology (engines and materials) and better fuels (biofuels). In addition to that, airlines must offset their emissions to be CO2 neutral with environmental projects through offsetting schemes, for example EU-ETS in Europe, CORSIA, new ongoing programme promoted by United Nations and IATA. The CORSIA and EU-ETS programmes are based in compensating emissions by financing a reduction in emissions elsewhere, and require detailed and specific procedures for data monitoring, verification and reporting, involving several stakeholders as airlines, independent auditors, national and supranational government agencies and finally, companies with environmental projects (renewable energy, carbon and methane sequestration, energy efficiency, technological process improvements) and carbon markets. The complexity and the uncertainty of data measuring, data gathering, data validation process, the fine-grained data reporting tracking and its custody, from a single flight to the national/supranational data registry is the key for the success of the quality of emissions data and its compensation through the whole process. We developed a POC, named ARETA (Aviation Real Time Environmental Token Accreditation) as an automated data platform that would help for the complex offsetting schemes processes, based on Monitoring, Verification and Report paradigm proposed in the offseting schemes. Also, the solution acts as carbon trading platform. Our main POC’s functionalities are: • Estimating in near-real time CO2 aviation emissions from real time flights open data. • Tokenizing its emissions and trading them through a Blockchain. • Creating a data-governed big data repository. • Visualizing dashboards with the data collected and processed for further use cases. Some of them in near-real time. • We also included, the estimation, in near-real time, of the related air quaility emissions (NOx, CO and HC) in airports and in en-route flight segments. We simulated the participation of all the stakeholders in the same unified platform for simplifyng the process and the emissions units (carbon tonnes) for setting a source of thruth data repository using Big Data and Blockchain capabilities, guiding the verification process through Smart Contracts and providing them dashboards for analyze the data. All the POC has in every step Data Governance disciplines in consideration. For developing the POC, we used open source tools as Neo4J, Spark, Elastic, MongoDB, Redis, BigchainDB and Kafka with Python as the core language. We will show: • the architecture and the pipeline of ARETA, using Big Data, Blockchain and Data Governance domains used in this POC. • The Data Governance we applied in the POC. Data lineage, data glossary / dictionary, data quality, metadata and master data management. • The dashboards we built. • And one more thing: unexpectedly, we started the POC in march in the middle of the COVID scemario, so we also extended the use cases for analizyng some of the impacts, we will show you some data and visualizations about the COVID scenarios.