The central goal of the Paris Agreement is to limit global warming to well below 2C above pre-industrial levels, but preferably 1.5C.
This difficult task will require policies and tools that enable all sectors of society to drastically reduce greenhouse gas (GHG) emissions to zero.
Enacting the most effective and efficient strategies to reduce emissions starts with knowing in detail where, when and how much of these greenhouse gases we are emitting, followed by implementing emission reduction policies and tracking our progress.
Is it possible to track carbon dioxide (CO2) emissions and emission reductions from space? New research from my group shows that it does.
Why is CO2 important?
CO2 is the main greenhouse gas driving climate change. The burning of fossil fuels for electricity generation, building heating, industry and transport has raised CO2 in our atmosphere far beyond natural levels.
Currently, reporting of CO2 emissions is done primarily by counting the mass of fossil fuels purchased and used, and then calculating expected emissions, not actual measurements of atmospheric CO2. Finer details about exactly when and where emissions occurred are often not available, but more transparent tracking of CO2 emissions could help track the effectiveness of policies to reduce emissions.
Today GPS satellites help us get around, weather satellites track weather systems, and communication satellites transmit television, internet, and telephone signals. It’s time we use satellites to help tackle the biggest challenge humanity has ever faced: climate change.
Satellites to measure CO2
A global network of ground-based CO2 measurements began in 1957 and currently consists of more than a hundred stations worldwide. Accurate and precise measurements from these stations have revealed much about changes in global atmospheric CO2 and Earth’s global carbon cycle, but we cannot place these stations everywhere on Earth.
Satellites can observe the entire planet. Those measuring CO2 in the lower atmosphere near the Earth’s surface (where CO2 emissions and CO2 uptake by plants occur) first began taking measurements in 2002. Since then they get better and better, but there have been setbacks over time. way
Nearly a decade of NASA effort developed the Orbiting Carbon Observatory (OCO) satellite to make accurate measurements of atmospheric CO2 on Earth.
NASA developed the Orbiting Carbon Observatory satellite to make precise measurements of atmospheric CO2 on Earth. (NASA/JPL), author provided
In 2009, OCO was lost due to a launch problem. After sustained advocacy for rebuilding this important climate mission, NASA secured new funding to launch the OCO-2 satellite in 2014 and OCO-3 to the International Space Station in 2019.
The OCO missions were designed to improve our understanding of CO2 uptake by vegetation, also known as the terrestrial carbon sink. But what about CO2 emissions from fossil fuels?
A new way to verify CO2 emissions
In 2017, I led a research team that published the first study showing that we can quantify CO2 emissions at the scale of an individual power plant using OCO-2 observations.
Because OCO-2 was not designed for this purpose, its coverage and infrequent visits were inadequate for operational monitoring of global CO2 emissions, but we can still quantify emissions in certain cases when the satellite lit passes close enough and gets a good view without clouds.
The OCO-3 is very similar to the OCO-2, but has an additional pointing mirror that allows it to better map CO2 around targets of interest such as the Bełchatów Power Plant in Poland, the Combustion Power Plant of fossil fuels and the largest source of CO2 in Europe.
Bełchatów Power Station, the largest fossil-fired power station in Europe. (Shutterstock)
With ten clear views of Bełchatów’s CO2 emission plumes captured by OCO-2 and OCO-3 from 2017 to 2022 analyzed in our new study, we were able to determine the emissions for those days.
European power plants report hourly power generation, but only annual CO2 emissions. Power generation fluctuates with electricity demand and generator unit shutdowns (for maintenance or decommissioning) and CO2 emissions are expected to fluctuate proportionally.
We confirmed this using OCO-2 and OCO-3 in our recent paper, which showed that satellite observations can track changes in facility-level CO2 emissions. This means that satellites can be used to verify (or disprove) reported CO2 emissions reductions that result from climate change mitigation, such as mandated efficiency improvements, carbon capture and storage technology, etc. .
A high CO2 plume resulting from coal combustion is evident from the Bełchatów power station in OCO-3 observations. (Ray Nassar), Contributed Author
Emissions monitoring for the Paris Agreement
Our approach can be applied to more power plants or modified for CO2 emissions from OCO-2 and OCO-3 cities or countries. We can also try to integrate satellite observations with CO2 monitoring from the ground or aircraft.
Although we are already working on this, progress will only be incremental until the launch of the Copernicus Anthropogenic CO2 Monitoring Mission or “CO2M”, funded by the European Commission. CO2M consists of two satellites, with the aim of launching in late 2025.
These satellites will provide around 50 times more coverage than OCO-2 and OCO-3 combined and will form the space component of the European CO2 Emissions Monitoring, Verification and Support (MVS) system.
CO2M will be a big step forward, but like successful global climate action, it requires contributions from many countries. Robust long-term operational global monitoring of GHG emissions will require a constellation of satellites contributed by several countries as part of an integrated global observing system.
Hopefully, with new, more detailed and transparent monitoring of human-caused greenhouse gas emissions to assess and guide us toward the most effective policies, society can achieve emissions reductions necessary to reach net zero on time.