This article was originally published on The conversation. (opens in new tab) The publication contributed the article to Space.com Expert Voices: Op-Ed & Insights.
Dr. Ray Nassar (opens in new tab)Research Fellow, Department of Physics, University of Toronto.
The central goal of the United Nations Paris Agreement is to limit global warming to well below 2 C above pre-industrial levels, but preferably 1.5 C. This difficult task will require policies and tools that enable every sector of society to drastically reduce greenhouse gas (GHG) emissions to eventually reach zero.
Implementing the most effective and efficient strategies to reduce emissions starts with knowing in detail where, when and how much of these greenhouse gases we emit to Earth, followed by implementing emission reduction policies and monitoring our progress.
Is it possible to monitor carbon dioxide (CO2) emissions and emission reductions from space? New research from my team (opens in new tab) shows that it is.
Related: NASA cancels climate change satellite to track greenhouse gases
Why CO2 matters
According to the Environmental Protection Agency, CO2 is the main greenhouse gas that drives climate change (opens in new tab). Burning fossil fuels to generate electricity, heat buildings, industry and transport has increased CO2 in the Earth’s atmosphere far beyond natural levels.
Currently, CO2 emissions are reported primarily by taking into account the mass of fossil fuels purchased and used, and then calculating expected emissions — not actual atmospheric CO2 measurements. Finer details of when and where emissions occurred are often not available, but more transparent tracking of CO2 emissions could help monitor the effectiveness of policies to reduce emissions.
Today GPS satellites (opens in new tab) help us get around, weather satellites (opens in new tab) monitor weather systems and communication satellites, they relay television, internet and telephone signals. It’s time to use satellites to help tackle the biggest challenge humanity has ever faced – climate change.
CO2 measuring satellites
A global network of ground-based CO2 measurements began in 1957 (opens in new tab) and now consists of over a hundred stations around the world (opens in new tab). Accurate and precise measurements from these stations have revealed much about changes in global atmospheric CO2 and the Earth’s overall carbon cycle, but we cannot place these stations everywhere on Earth.
Satellites can observe the entire planet. Those who measure CO2 in the lower atmosphere near the Earth’s surface (where CO2 emissions and CO2 uptake by plants occur) first started taking measurements in 2002. Since then, they’ve gotten better at doing it, but there have been setbacks along the way.
About a decade of effort by NASA went into developing the Orbiting Carbon Observatory (OCO) (opens in new tab) satellite for precise measurements of atmospheric CO2 across the Earth.
In 2009, OCO was lost due to a launch problem. Following continued support to rebuild this important climate mission, NASA has secured new funding for the launch of OCO-2 (opens in new tab) satellite in 2014 and OCO-3 on the International Space Station in 2019.
The OCO missions were designed to improve our understanding of the CO2 absorption of vegetation, also known as the terrestrial carbon sink (opens in new tab). But what about CO2 emissions from fossil fuels?
Read more: CO2 satellite: NASA’s Orbiting Carbon Observatory-2 mission in pictures
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 a single power plant using OCO-2 observations (opens in new tab).
Since OCO-2 was not designed for this purpose, its coverage and infrequent visits have been insufficient to operationally monitor CO2 emissions, but we can still quantify emissions in selected cases when the satellite passes close enough and has good cloudless view (opens in new tab).
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 Station (opens in new tab) in Poland, Europe’s largest fossil fuel power plant and CO2 source.
With ten clear views of the CO2 emission plumes from Bełchatów imaged by OCO-2 and OCO-3 from 2017-2022 and analyzed in our new study (opens in new tab)we were able to determine the emissions on those days.
European power plants report hourly electricity production (opens in new tab) but only annual CO2 emissions. Electricity production fluctuates with electricity demand and plant outages (for maintenance or decommissioning) and CO2 emissions are expected to fluctuate accordingly.
We confirmed this using OCO-2 and OCO-3 in our recent work (opens in new tab), which showed that satellite observations can track changes in CO2 emissions at the facility level. This means that satellites can be used to verify (or disprove) reported reductions in CO2 emissions resulting from climate change mitigation — such as mandatory efficiency improvements, carbon capture and storage technology, etc.
Watch broadcasts on the Paris Agreement
Our approach can be applied to more power plants or modified for CO2 emissions from cities or countries with OCO-2 and OCO-3 (opens in new tab). We can also try to integrate satellite observations with CO2 monitoring from the ground or from aircraft.
While we are already working on this, progress will only be incremental until the launch of the Copernicus Anthropogenic CO2 Monitoring or ‘CO2M’ mission funded by the European Commission. CO2M consists of two satellites, targeted for launch in late 2025.
These satellites will provide approximately 50 times more coverage than OCO-2 and OCO-3 combined and will form the space-based component of Europe’s CO2 Emissions Monitoring, Verification and Support (MVS) system. (opens in new tab).
CO2M will be a significant advance, but like successful global climate action, it requires contributions from many countries. Long-term robust operational monitoring of GHG emissions will require a constellation of satellites contributed by many countries as part of an integrated global observing system (opens in new tab).
Hopefully, with new, more detailed and transparent monitoring of anthropogenic greenhouse gas emissions to assess and guide us towards more effective policies, society can achieve the emissions reductions needed to reach net zero in time (opens in new tab).
This article is republished from The Conversation (opens in new tab) with a Creative Commons license. Read the original article (opens in new tab).
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