Climate change: Why the EU wants to accelerate Earth observation from space

Earth from space

Air pollution, sea level, land artificialisation… Since 2014, the European Union has been acquiring a fleet of satellites to observe the state of the Earth. This is the Copernicus program, whose future will be discussed in Toulouse on Wednesday and Thursday

One thousand eight hundred plumes of methane, a powerful greenhouse gas, including 1,200 observed over oil and gas extraction sites. This is what an international team of researchers, led by the French Laboratory for Climate and Environmental Sciences (LSCE) and associated with the company Kayrros, has managed to identify across the globe. “These releases may be accidental or related to maintenance operations,” the scientists said. And yet, these 1,800 methane leaks have an impact comparable to that of the traffic of 20 million vehicles for one year,” they calculate.

This work was published in the scientific journal Science on February 4. To achieve this mapping, the researchers systematically analyzed thousands of images produced daily for two years by the Sentinel-5 SP satellite of the European Space Agency (ESA).


A valuable support for the ecological transition?

This is a concrete application of Copernicus, the European Union’s Earth monitoring program. Since 2014, eight satellites have been placed in orbit around the Earth to observe it from every angle. This is phase “one” of the program, which ended last year. The second phase has already been approved by the EU and will see the launch of six new Sentinels between 2025 and 2029. And on Wednesday and Thursday, in Toulouse, during a high-level symposium on the sidelines of the informal meeting of European space ministers, the future of Copernicus up to 2035 will be discussed.

This is proof that the European Union is not planning to stop Copernicus any time soon. Quite the contrary. We are entering a critical period in which we will have to drastically reduce our greenhouse gas emissions, and to do so, we will have to be accompanied,” says climatologist Robert Vautard, director of research at the Pierre-Simon Laplace Institute (LPSL). However, “the majority of climate change indicators can only be monitored correctly from space”.

Air quality, sea level rise, ground temperature

In addition to locating methane leaks, the Sentinel-5SP, with its spectrometer*, “can analyze air quality by measuring components such as nitrogen dioxide (NO2) [an indicator of automobile pollution], ozone, sulfur dioxide and aerosols,” reports H. Laur, head of the space mission. Laur, head of Earth observation missions at the European Space Agency (ESA).

Henri Laur also cites “Sentinel-2”, “probably the best known and which gives images of the entire surface of the Earth every five days and in high resolution (with a precision of ten meters). A valuable instrument for monitoring the state of vegetation – particularly forests – and land artificialisation. Other Copernicus satellites, through the various instruments they carry, will measure the rise in sea level, ground temperatures on the surface of the oceans, monitor sea ice, identify local pollution such as oil slicks … Sentinel 3 even has on board a water color sensor that can monitor the levels of microalgae in our waters, both carbon sinks and the basis of the marine food chain.

Concrete applications, from agriculture to urban planning

The new generation of satellites expected from 2025 should improve the observation of parameters already monitored by Copernicus and add new ones. “We are currently developing CO2M [Copernicus Carbon Dioxide Monitoring Mission], a satellite that will specialize in measuring the quantities of CO2 (the main greenhouse gas) released into the atmosphere, which should be launched around 2026.

But the challenge of Copernicus is not only to monitor the health of the Earth. It is also to find concrete applications for these satellite data,” adds Vautard, who is working on the downstream part of the Copernicus program. “By combining them with forecasting models, we can make climate projections for very short and much longer periods,” explains the climatologist. Agriculture is probably the market that should benefit the most from Copernicus, allowing projections on agricultural yields, risks of drought, especially allowing better management of water and planting periods. “But we have also recently worked with the city of Paris and the Ile-de-France region on urban planning scenarios to adapt to climate change and expected heat waves. And on its website, Copernicus lists, on 26 pages, concrete applications or planned applications based on its satellite data. From the “blue economy” to health, forest management, optimization of renewable energy production … All over the world.


Copernicus, future policeman of the Paris agreements?

This is one of the strengths of Copernicus: “The EU does not charge for the program’s data,” he says. Anyone, including private actors, can use them to imagine climate services and generate economic activity. These two days of symposium in Toulouse should allow us to project even further by setting priorities for the third generation of Copernicus satellites – the one that should be put into orbit by 2035. The challenge is to improve the accuracy of the indicators already monitored by Copernicus and to identify new ones to be observed and to imagine future applications.

One of these is to make Copernicus the future policeman of the Paris Agreement on climate change? It would not be the first time that we monitor compliance with international treaties from space,” says Oliver Sanguy. This is already the case, for example, with the non-proliferation of nuclear weapons. The stakes are just as high on climate change. “We must now ensure that countries fulfill their part of the contract and drastically reduce their greenhouse gas emissions. Relying only on their declarations will not be enough. This is one of the goals of the CO2M satellite, which will measure the quantities of CO2 produced by human activity. In the same way, we could very well imagine that this mapping of the 1,800 methane plumes would be followed by a rebuke of countries and companies that do not make sufficient efforts to avoid these leaks.