NASA’s Earth observation satellite has helped researchers monitor carbon dioxide emissions in more than 100 countries around the world. The pilot project offers a powerful new look at these countries’ carbon dioxide emissions and how much is removed from the atmosphere by forests and other carbon sinks within their borders. The resulting data shows how space-based vehicles can supplement information about Earth as countries work to meet climate goals.

An international study by more than 60 researchers used a network of ground-based observations alongside measurements taken by NASA’s Orbiting Carbon Observatory-2 (OCO-2) mission to measure increases and decreases in atmospheric carbon dioxide concentrations from 2015 to 2020. . . Using this measurement-based (or “top-down”) approach, the researchers were able to infer the balance of how much carbon dioxide is released and removed.

While the OCO-2 mission was not specifically designed to assess each country’s emissions, the findings of more than 100 countries came to light in a timely manner. The first global turn – the process of assessing the world’s collective progress towards limiting global warming as outlined in the 2015 Paris Agreement – ​​will take place in 2023.

This animation shows the annual fossil fuel emissions of more than 100 countries from 2015 to 2020. High-emission countries, including the US and China (shown here in bold red), appear on the page when compared to lower-emissions countries.

NASA Earth Sciences Division director Karen St. “NASA is focused on providing Earth science data that addresses real-world climate challenges, such as helping governments around the world measure the impact of their efforts to reduce carbon emissions,” said Germain. Headquarters NASA offices in Washington. “This is an example of how NASA is improving and increasing its efforts to measure carbon emissions to meet users’ needs.”

Traditional activity-based (or bottom-up) carbon measurement approaches rely on counting and estimating the amount of carbon dioxide emitted by all sectors of the economy, such as transport and agriculture. A bottom-up carbon inventory is critical for assessing progress in emissions reduction efforts, but requires significant resources, expertise and knowledge of the scale of the activities involved.

That’s why they say developing an emissions and abatement database using a top-down approach can be particularly helpful for countries that don’t have traditional inventory development resources. In fact, the scientists’ findings include data from more than 50 countries that have not reported emissions for at least the past 10 years.

The research offers a new perspective by tracking both fossil fuel emissions and changes in the overall carbon “stock” of ecosystems, including trees, shrubs and soils. These data are particularly useful for monitoring carbon dioxide fluctuations associated with land cover change. In the Global South, which includes regions of Latin America, Asia, Africa and Oceania, deforestation emissions alone are responsible for a disproportionate amount of overall carbon emissions. In other parts of the world, the results show some reductions in atmospheric carbon concentrations due to improved land use and reforestation.

The authors noted that bottom-up methods are needed to estimate carbon dioxide emissions and removal from ecosystems. However, these methods are vulnerable to uncertainty when data is missing or the net effect of certain activities, such as logging, is not fully known.

“Our top-down estimates provide an independent assessment of these emissions and absorptions, so we can check both approaches for consistency, although they cannot replace the detailed process understanding of traditional bottom-up methods,” said study author and researcher Philip Siais. Director of the Laboratoire des Sciences du Climat et de l’Environnement in France.

This map shows changes in the amount of carbon stored in organic matter on land, called terrestrial carbon stock changes, from 2015 to 2020. Actions such as improved land management and deforestation, which are more common in the tropics than elsewhere, affect these exchange stocks.

carbon tracking

The study provides a complex picture of carbon’s movement across Earth’s land, ocean and atmosphere. In addition to the direct anthropogenic effects described by national inventories, unmanaged ecosystems such as some tropical and boreal forests where humans have minimal footprints can sequester carbon from the atmosphere, thereby reducing potential global warming.

“National inventories are designed to monitor how management policies affect CO2 emissions and removals,” said study author Noel Cressy, a professor at the University of Wollongong in Australia. “But the atmosphere doesn’t care if the CO2 is emitted from deforestation in the Amazon or wildfires in the Canadian Arctic. Both processes will increase the atmospheric CO2 concentration and cause climate change. Therefore, it is extremely important to monitor the carbon balance of unmanaged ecosystems and detect any changes in carbon uptake.”

Looking ahead, the researchers said their pilot projects could be developed to understand how countries’ emissions are changing.

“Consistent high-quality observations are critical to these downward estimates,” said lead author Brendan Byrne, a scientist at NASA’s Jet Propulsion Laboratory in Southern California. “Continuous observations from OCO-2 and surface areas will allow us to monitor how these emissions and absorptions change as the Paris Agreement is implemented. Future international missions, which will provide an advanced map of CO2 concentrations around the world, will allow us to refine these downward estimates and provide more accurate estimates of emissions and absorptions by countries. will give.”