NASA has calculated carbon dioxide emissions and removals for more than a hundred countries using satellite measurements. This approach makes it possible to discern which nations reduced or increased their emissions from 1990 to 2020 by year and by gas type.
The research offers new insights into the carbon dioxide released within each country and how much carbon dioxide forests and other sinks remove from the atmosphere inside their borders.
On the map above, countries that remove more carbon dioxide than they emit appear in shades of green, while nations with the highest emissions show up in tan or red. The link to observe emissions year by year for each country can be consulted in the cited resource for ongoing changes.
International research, published in Earth System Science Data, used a surface observation network alongside measurements from NASA’s Orbiting Carbon Observatory-2 mission to track increases and decreases in atmospheric carbon dioxide concentrations between 2015 and 2020. Led by more than 60 researchers, this measurement-based, or top-down, approach enabled a clearer view of the balance between carbon released and carbon removed.
Spain: negligible decrease
In Spain, the study shows a reduction in greenhouse gas emissions by 5.87% in recent years, well below the European Union average. Over the same period, emissions fell by 36% in the EU as a whole.
Nearby Portugal reduced emissions by 19%, France by 26%, Italy by 32%, and the United Kingdom by 49%, with Germany showing a similar trend.
Although the OCO-2 mission was not designed to estimate emissions for individual countries, the results for more than 100 nations arrive at a critical moment. A global inventory will be produced in 2023 to assess progress toward limiting global warming under the Paris Agreement framework established in 2015.
The traditional activity-based, or bottom-up, approaches to carbon measurement rely on counting and estimating emissions from all sectors of an economy, including transport and agriculture. Bottom-up inventories are essential for tracking progress in reduction efforts but require substantial resources, expertise, and knowledge of the scope of related activities.
Thus, the development of a comprehensive emissions and removal database through a top-down approach, based on measurements, may prove particularly useful for countries lacking traditional inventory sources. In fact, the study includes data from more than 50 countries that have not reported emissions for at least the past decade.
All kinds of publications
The study offers a fresh perspective by tracking both fossil-fuel emissions and total changes in ecosystem carbon stocks, including trees, shrubs, and soil. The data are especially valuable for monitoring carbon dioxide fluctuations linked to land cover change.
Deforestation alone accounts for a disproportionate share of global carbon output, affecting regions in Latin America, Asia, Africa, and Oceania. In other parts of the world, reductions in atmospheric carbon concentrations are tied to improved land management and reforestation efforts.
The authors note that bottom-up methods remain necessary to estimate emissions and removals from ecosystems. However, these methods can be uncertain when data are missing or the net effects of individual activities, such as logging, are not fully known.
New measurements complement previous ones and provide an independent check on emissions and removals, according to the lead author Philippe Ciais, director of the Laboratoire des Sciences du Climat et de l’Environnement in France. The study presents a complex picture of how carbon moves across Earth’s land, oceans, and atmosphere.
Beyond the direct human impact shown in national inventories, unmanaged ecosystems with minimal human interference, such as certain tropical and boreal forests, can sequester carbon from the atmosphere, helping to curb potential global warming.
According to Noel Cressie, author of the study and a professor at the University of Wollongong in Australia, national inventories aim to assess how management policies affect CO2 emissions and removals. He notes that the atmosphere does not distinguish between CO2 originated from deforestation in the Amazon and CO2 from wildfires in the Canadian Arctic. Both processes raise atmospheric CO2 and drive climate change, underscoring the need to monitor carbon balance across unmanaged ecosystems and detect shifts in carbon uptake.
Looking ahead, the researchers suggest their pilot projects could be refined to better track how emissions change in each country.
A data-checking resource is available for examining country-specific figures in the cited repository.
Reference work is available in the cited scientific article series.
……
Notes about data availability remain part of ongoing discussions within the environmental science community.