Nasa map shows which countries are releasing and absorbing CO2

The map is based on measurements from an Earth-observing satellite (NASA)
The map is based on measurements from an Earth-observing satellite (NASA)

A Nasa diagram and video shows which countries are releasing and absorbing carbon dioxide around the world - based on satellite observations between 2015 and 2020.

The map shows which countries absorbed CO2 (via carbon ‘sinks’ such as forests) and which emitted it through household and industrial emissions (and other factors).

Countries where more carbon dioxide was removed than emitted appear as green depressions, while countries with higher emissions are tan or red and appear to pop off the page.

Both use data from an Earth-observing Nasa spacecraft, the Orbiting Carbon Observatory-2 (OCO-2) mission, plus a network of surface-based observations.

The video and map are based on increases and decreases in atmospheric carbon dioxide concentrations (a ‘top down’ observation), which are used to calculate how much carbon dioxide was emitted and removed.

The OCO-2 mission was not specifically designed to estimate emissions from individual nations, but the findings from the 100-plus countries are well-timed.

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The first Global Stocktake, a process to assess the world's collective progress toward limiting global warming, as specified in the 2015 Paris Agreement, takes place in 2023.

Karen St. Germain, director of Nasa's Earth Science Division at Nasa Headquarters in Washington says, "Nasa is focused on delivering Earth science data that addresses real world climate challenges - like helping governments around the world measure the impact of their carbon mitigation efforts.

“This is one example of how Nasa is developing and enhancing efforts to measure carbon emissions in a way that meets user needs."

Traditional activity-based (or "bottom-up") approaches to carbon measurement rely on tallying and estimating how much carbon dioxide is being emitted across all sectors of an economy, such as transportation and agriculture.

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Compiling them requires considerable resources, expertise, and knowledge of the extent of the relevant activities.

This is why developing a database of emissions and removals via a top-down approach could be especially helpful for nations that lack traditional resources for inventory development, the researchers say.

Philippe Ciais, a study author and research director at the Laboratoire des Sciences du Climat et de l'Environnement in France said: "Although they cannot replace the detailed process understanding of traditional bottom-up methods, we can check both approaches for consistency."

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The scientists' findings include data for more than 50 countries that have not reported emissions for at least the past 10 years.

The study provides a new perspective by tracking both fossil fuel emissions and the total carbon "stock" changes in ecosystems, including trees, shrubs, and soils.

The data is particularly useful for tracking carbon dioxide fluctuations related to land cover change.

Emissions from deforestation alone make up a disproportionate amount of total carbon output in the Global South, which encompasses regions of Latin America, Asia, Africa, and Oceania.

In other parts of the world, the findings indicate some reductions in atmospheric carbon concentrations via improved land stewardship and reforestation.