NASA's OCO-2 satellite tracks carbon emissions for over 100 countries

Using this measurement-based approach, the researchers were able to infer the balance of how much carbon dioxide was emitted and removed. The map generated from the study shows the mean net emissions and removals; countries where more carbon dioxide was removed than emitted appear as green depressions, while countries with higher emissions are tan or red.

Although the OCO-2 mission was not designed to estimate emissions from individual nations, the findings from the 100-plus countries come at an opportune time. The first Global Stocktake, a process to assess the world’s collective progress towards limiting global warming as specified in the 2015 Paris Agreement, takes place in 2023.

“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,” said Karen St. Germain, Director of NASA’s Earth Science Division at NASA Headquarters in Washington. “This is one example of how NASA is developing and enhancing efforts to measure carbon emissions in a way that meets user needs.”

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 are 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.

The authors of the study note that traditional activity-based 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.

Bottom-up carbon inventories are critical for assessing progress towards emission-reduction efforts, but compiling them requires considerable resources, expertise, and knowledge of the extent of the relevant activities.

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 study authors assert. In fact, the scientists’ findings include data for more than 50 countries that have not reported emissions for at least the past 10 years.

“Our top-down estimates provide an independent estimate of these emissions and removals, so although they cannot replace the detailed process understanding of traditional bottom-up methods, we can check both approaches for consistency,” said Philippe Ciais, a study author and research director at the Laboratoire des Sciences du Climat et de l’Environnement in France.

NASA and the Italian space agency Agenzia Spaziale Italiana (ASI) have announced a partnership to develop a satellite, called the Multi-Angle Imager for Aerosols (MAIA), to study the effects of airborne particle pollution on human health.

The MAIA mission is set to launch before the end of 2024 and will mark the first-time epidemiologists and public health researchers have been directly involved in the development of a satellite mission.

The MAIA observatory will consist of a satellite provided by ASI and a science instrument built at NASA's Jet Propulsion Laboratory in Southern California. The mission will collect and analyse data from the observatory, sensors on the ground, and atmospheric models, and then relate those results to human birth, death, and hospitalization records to answer pressing questions about the health impacts of solid and liquid particles that contaminate the air we breathe.

Airborne particle pollution has been linked to respiratory diseases such as asthma and lung cancer, cardiovascular diseases such as heart attack and stroke, and adverse reproductive and birth outcomes, including premature birth and low infant birth weight. The mission's main objective is to study whether exposures to different types of particle pollution have differing health impacts.

Over the course of its three-year mission, MAIA will focus on 11 primary target areas that cover major urban centers around the globe, including Los Angeles, Atlanta, and Boston in the United States; Rome; Addis Ababa, Ethiopia; Barcelona, Spain; Beijing; Johannesburg; New Delhi; Taipei, Taiwan; and Tel Aviv, Israel. The mission will also collect some data over 30 secondary target areas throughout the world.

Francesco Longo, head of the Earth Observation and Operation Division at ASI, said, “MAIA marks an important moment in the long history of cooperation between NASA and ASI, and it symbolizes the best our two agencies can marshal in terms of expertise, knowledge, and Earth-observation technology. The science produced by this joint mission will provide benefits to humanity for years to come.”

The agreement between NASA and ASI was finalized in January 2023 and continues decades of collaboration, including on the Cassini mission to Saturn, which launched in 1997.

In 2022, ASI's ArgoMoon tiny cube satellite was a secondary payload aboard the Artemis I mission's Orion spacecraft. The agency's Light Italian CubeSat for Imaging Asteroids, or LICIACube, played a crucial role in NASA's Double Asteroid Redirection Test (DART) mission.

MAIA's measurements of sunlight reflecting off airborne particles will help researchers determine the abundance, size, and optical properties of certain pollutants in the atmosphere. Using such data in conjunction with surface-based measurements will help researchers decipher the particles' chemical composition.

The mission will collect data on short-term exposure to particulate pollution over the course of days, chronic exposure, which can last many years, and "sub-chronic" exposure, such as the monthslong inhaling of pollutants that might occur during pregnancy, which can lead to adverse health effects for a mother and infant.

MAIA is a joint Earth-observing mission between NASA and ASI. NASA's Space Communications and Navigation program (SCaN) will provide uplink and downlink services for commands and data, and NASA's Atmospheric Science Data Centre will provide computational resources to generate and archive science products. ASI will provide the PLATiNO-2 spacecraft, contribute launch services, and host the mission operations centre.