TROPOMI's Future
We have heard rumors that the European Union is planning to stop funding and effectively end the TROPOMI measurements onboard the Sentinel-5P satellite, now that Sentinel-5 is in orbit. Through this petition, we would like to express our deep concern about this. Before getting into the specific reasons, we first want to highlight the importance of the TROPOMI data set.
Since its launch in 2017, TROPOMI data have been used by thousands of users in academia, governments and the private sector. TROPOMI data were used to visualize the impacts from the COVID shutdowns, to quantify trends in air pollutant emissions, to discover major methane leaks, to track volcanic plumes, and to quantify the oxidizing capacity of the atmosphere. A search for papers in the Web of Science that have "TROPOMI" or "Sentinel 5P" in their abstracts currently yields over 1,700 papers, which as a whole have been cited by more than 33,000 other papers. These numbers are still growing exponentially (see above figure).
Here is why we are deeply concerned about ending the TROPOMI measurements:
- Ending a hugely successful mission that is not anywhere near its end-of-life is a waste of the investments made and the countless hours that went into planning and executing the mission.
- The Sentinel 5 data are as yet unproven. Having the two missions overlap for several years is imperative to even consider ending the TROPOMI measurements.
- TROPOMI data are being used by thousands of users, if not more, in academia, government and the private sector. Ending the TROPOMI mission will be very disruptive to their work.
- Given the importance of the data, the redundancy of having multiple instruments in space is not a luxury. The unexpected loss of contact with MethaneSat is a good reminder that space-based instruments can and will develop problems.
- Sentinel 5 is in a morning orbit, while Sentinel 5P, which carries TROPOMI, is in an afternoon orbit. This is important because some of the gases measured by TROPOMI and Sentinel 5 are reactive and are not the same in the morning and afternoon. Combining the data yields unique insights into chemical processes in the atmosphere.
We urge the European Union to continue the TROPOMI measurements in the foreseeable future. Please join us in signing this petition.
Updates
Reached 250 supporters
June 19, 2026
Reached 100 supporters
June 1, 2026
102 Comments
TROPOMI is by far the most successful methane monitoring instrument in history. It is the work horse of our community and has taken years to get the data quality to be sufficient for this purpose. Sentinel 5 is not a copy and will take a very long time to make useful methane retrievals for the community and planet.
S5 is not a replacement for S5P. Observations are complementary, at different times. And even if they were at the same time, a long-enough overlap time is necessary to demonstrate data continuity, otherwise the whole idea of long-term data is lost!
Sentinel-5 is NOT a replacement of Seintel-5p, it is an addition hat helps us understand diurnal cycle of emissions and air quality. NOx-photochemistry has a strong diurnal cycle, with the bet plume-detectibility in the early afternoon, the overpass time of TROPOMI/Sentinel-5P
I agree with all the reasons stated here. In addition, S5p and S5 are serving as important LEO observations to cross calibrate observations from the Geostationary Air Quality constellation and provide morning/afternoon observations with similar spatial resolution in the other parts of the world without GEO AQ observations.
I worked with TROPOMI data 5 years ago that has underpinned recommendations to oil & gas companies to manage large methane leaks. This is really important data that needs overlap with any new satellite data before retiring.
I'm a founder of an early stage startup from Germany and we're using TROPOMI data for our product development.
The TROPOMI measurements are critical for my action on climate change.
Sign Petition
We never post to your account. Social sign-in is used only to verify your signature.
Add a comment?
Your signature will be added via . Tell others why you're signing — it's optional.
By signing, you accept our Terms and Privacy Policy and agree to occasional emails about petitions. Unsubscribe anytime.
Share this petition
Share this petition to help it reach more people.
Your share link
TROPOMI's Future
We have heard rumors that the European Union is planning to stop funding and effectively end the TROPOMI measurements onboard the Sentinel-5P satellite, now that Sentinel-5 is in orbit. Through this petition, we would like to express our deep concern about this. Before getting into the specific reasons, we first want to highlight the importance of the TROPOMI data set.
Since its launch in 2017, TROPOMI data have been used by thousands of users in academia, governments and the private sector. TROPOMI data were used to visualize the impacts from the COVID shutdowns, to quantify trends in air pollutant emissions, to discover major methane leaks, to track volcanic plumes, and to quantify the oxidizing capacity of the atmosphere. A search for papers in the Web of Science that have "TROPOMI" or "Sentinel 5P" in their abstracts currently yields over 1,700 papers, which as a whole have been cited by more than 33,000 other papers. These numbers are still growing exponentially (see above figure).
Here is why we are deeply concerned about ending the TROPOMI measurements:
- Ending a hugely successful mission that is not anywhere near its end-of-life is a waste of the investments made and the countless hours that went into planning and executing the mission.
- The Sentinel 5 data are as yet unproven. Having the two missions overlap for several years is imperative to even consider ending the TROPOMI measurements.
- TROPOMI data are being used by thousands of users, if not more, in academia, government and the private sector. Ending the TROPOMI mission will be very disruptive to their work.
- Given the importance of the data, the redundancy of having multiple instruments in space is not a luxury. The unexpected loss of contact with MethaneSat is a good reminder that space-based instruments can and will develop problems.
- Sentinel 5 is in a morning orbit, while Sentinel 5P, which carries TROPOMI, is in an afternoon orbit. This is important because some of the gases measured by TROPOMI and Sentinel 5 are reactive and are not the same in the morning and afternoon. Combining the data yields unique insights into chemical processes in the atmosphere.
We urge the European Union to continue the TROPOMI measurements in the foreseeable future. Please join us in signing this petition.
Updates
Reached 250 supporters
June 19, 2026
Reached 100 supporters
June 1, 2026
102 Comments
Decommissioning TROPOMI would break the long-term afternoon observational record, disrupting a uniquely valuable dataset whose benefits to atmospheric science and society continue to grow with time.
TROPOMI is by far the most successful methane monitoring instrument in history. It is the work horse of our community and has taken years to get the data quality to be sufficient for this purpose. Sentinel 5 is not a copy and will take a very long time to make useful methane retrievals for the community and planet.
S5 is not a replacement for S5P. Observations are complementary, at different times. And even if they were at the same time, a long-enough overlap time is necessary to demonstrate data continuity, otherwise the whole idea of long-term data is lost!
Sentinel-5 is NOT a replacement of Seintel-5p, it is an addition hat helps us understand diurnal cycle of emissions and air quality. NOx-photochemistry has a strong diurnal cycle, with the bet plume-detectibility in the early afternoon, the overpass time of TROPOMI/Sentinel-5P
I agree with all the reasons stated here. In addition, S5p and S5 are serving as important LEO observations to cross calibrate observations from the Geostationary Air Quality constellation and provide morning/afternoon observations with similar spatial resolution in the other parts of the world without GEO AQ observations.
I worked with TROPOMI data 5 years ago that has underpinned recommendations to oil & gas companies to manage large methane leaks. This is really important data that needs overlap with any new satellite data before retiring.
I'm a founder of an early stage startup from Germany and we're using TROPOMI data for our product development.
The TROPOMI measurements are critical for my action on climate change.
Help this petition grow
Share it with friends to help reach 500 signatures.
Sign Petition
We never post to your account. Social sign-in is used only to verify your signature.
Add a comment?
Your signature will be added via .
Tell others why you're signing — it's optional.
Signing with Google or Facebook verifies your signature instantly — no email needed.
By signing, you accept our Terms and Privacy Policy and agree to occasional emails about petitions. Unsubscribe anytime.
Share this petition
Share this petition to help it reach more people.
Your share link
Petitions like this
Other petitions you might want to support
Scan to share
Anyone who scans this can sign the petition.
Decommissioning TROPOMI would break the long-term afternoon observational record, disrupting a uniquely valuable dataset whose benefits to atmospheric science and society continue to grow with time.