Posted 16 August 2021 in Blog, Science, Space.

In November 2021, the 26th UN Climate Change Conference of the Parties (COP26) will take place in Glasgow, Scotland, shining a light on the activities needed to combat global climate change. By providing data from satellites, Europe’s flagship Copernicus programme delivers evidence of our changing climate and supports vital climate research.

Find out how in this extract from RHEA’s OpenSpace 28 magazine featuring Susanne Mecklenburg, Head of the ESA Climate Office.

How does Copernicus support climate change research?

Copernicus provides data from ground, airborne and sea-based systems, with satellites providing data – and therefore insights – about our planet that would otherwise be impossible to capture.

Copernicus is led by the European Commission and implemented in partnership with Member States and organizations including the European Space Agency (ESA) and the European Union Space Programme Agency (EUSPA). Satellite data comes from the Sentinel missions operated by ESA and from contributing missions, some of which are operated by third parties. Together they provide huge volumes of data about the land, sea and air, all of which is freely available.

“All of them greatly advance our knowledge of the climate system in different ways,” explains Susanne Mecklenburg, Head of the ESA Climate Office.

Sentinel-1, with its all weather, day-and-night radar sensing capability, helps to monitor sea ice extent in the Arctic: a region that is warming three times faster than the global average.

Sentinel-2 is extremely important for the global stocktake – the 5-yearly mechanism that will review progress towards meeting the Paris Agreement goals. It provides information relating to agriculture, forestry and land use change, which can help determine the impact on net greenhouse gas emissions.

Sentinel-3 – Contributes data related to: land surface temperature and cover; ocean colour (related to the carbon cycle); and clouds and aerosols.

Sentinel-5P – Air quality and methane emissions, which showed the impact of COVID-19 lockdowns on air quality and GHG emissions.

Sentinel-6 – Soil moisture and ocean salinity to help improve weather and climate models.

What role does ESA’s Climate Office play?

ESA’s Climate Office plays a vital role in ensuring climate-related data, including that from satellites, is accurate and meaningful. “Our flagship programme is the Climate Change Initiative, launched in 2009,” says Mecklenburg.

“Within this, we are developing global data records of key components of the climate system, known as Essential Climate Variables, of which over 50 have been defined by the scientific community on behalf of the UNFCCC [United Nations Framework Convention on Climate Change]. We are currently looking at 21 of them, working with a climate community of around 450 experts to provide a physical evidence base to strengthen scientific understanding of the climate and how it is changing.”

What are Essential Climate Variables used for?

Copernicus Sentinel 1 satellite - image copyright ESA ATG medialab
Sentinel-1, with its all weather, day-and-night radar sensing capability, helps to monitor sea ice extent in the Arctic: a region that is warming three times faster than the global average. © ESA / ATG medialab

Essential Climate Variable (ECV) datasets are used by climate modellers to study what drives our climate and how elements interact, and to predict future changes. To ensure the satellite data is accurate, it is validated by various methods, including in situ measurements.

The best way to perfect models is to test them with examples where the results are already known. This is done using datasets of historical observations – which satellites provide on a continuous, regular and global scale – to check individual climate model outputs and compare how different models match up with each other.

ESA’s Climate Office ensures these historical datasets exist, with final ECV datasets transferred to providers of climate services, such as the Copernicus Climate Change Service (C3S), which make them publicly available.

What else can we do with ECVs?

We can improve our ability to address the challenges that climate change presents by using combinations of ECVs to address more complex science questions. So another role of ESA’s Climate Office is to combine related climate data records and models for this purpose.

The Sea Level Budget Closure project, for example, aims to reduce uncertainties around sea level change, which is one of the key indicators – and impacts – of climate change. By pulling together all the data and modelling related to the water cycle, it should help us to better understand the processes involved and identify what and how much is caused by human activity.

How can we measure emissions instead of estimating?

The first of the COP26 goals is to “Secure global net zero by mid-century and keep 1.5 degrees within reach”. To achieve this, individual nations need to understand exactly what emissions they are producing and take practical action to reduce them.

Currently, most countries estimate their emissions. In future, Europe’s Copernicus programme will help us to directly measure emissions to gain an accurate picture of the global situation. The planned CO2M satellite mission, for example, is designed to monitor anthropogenic CO2 and should be ready to provide data on actual emissions for the second Paris Agreement stocktake in 2028, based on data collected from 2026.

“With all of these different and complementary measurements that we will have, we will be able to pick up more of the different effects of climate change,” explains Mecklenburg. “This will help us to help our Member States in their global stocktake reporting.”

Copernicus Sentinel 2 satellite Copyright ESA/ATC medialab
Sentinel-2 is extremely important for the global stocktake – the 5-yearly mechanism that will review progress towards meeting the Paris Agreement goals. It provides information relating to agriculture, forestry and land use change, which can help determine the impact on net greenhouse gas emissions. © ESA / ATG medialab

Find out more

You can find out more about how Copernicus and individual satellite missions support climate change initiatives, and the role of the ESA Climate Office, in RHEA’s OpenSpace 28 magazine.

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