I’ll admit it: when they said I should go to this year’s Living Planet Symposium I was moderately enthusiastic. Even the word “earth observation satellites” is so unwieldy that I thought the topic was only interesting for – in the truest sense of the word – spaced-out fans and experts.
However, I had to realize that earth observation obviously has a large fan base. ESA counted 4700 registrations for the five-day symposium and visitors are spoiled for choice between more than 240 individual events. These included several lectures on the use of satellites to research and combat infectious diseases such as cholera, influenza or the zoonotic disease Ebola. That sounded so crazy that I got curious.
The person who brought the topic of satellite and space research out of the infinite expanse of space and brought it very close to the audience listening at the opening event was, of all people, an astronaut. Alexander Gerst told what it feels like to look at the planet from above.
Forest fires, cloud formations, the glow of big cities at night, huge river deltas. “Suddenly, when you see this big picture, so many things become clear,” said Gerst.
According to the motto: Sometimes it helps to look at the overall picture to get closer to the details. It is precisely this approach that researchers use when they use the images and numbers from Earth observation satellites for their work.
Destroyed forest, more Ebola
Larisa Lee-Cruz from the French agricultural research center CIRAD presented a study in which the researchers used data from earth observation satellites such as Sentinel to track down the transmission paths of the Ebola virus. Overall, Lee-Cruz said knowledge about the extremely deadly bat-borne infectious disease is still poor.
However, by comparing satellite images from different regions in West and Central Africa, the researchers are fairly certain that Ebola breaks out particularly often in those areas where large forest areas used to be fragmented or completely destroyed and instead used for agriculture.
The satellite images the scientists used show forest shrinking in an area of around 190 km² in Guinea over a period of ten years. It is data that the researchers can integrate into their investigations into the life and behavior of bats and the risk of virus transmission to humans.
“With the help of Earth observation, we can not only track changes in vegetation, but also measure temperatures and the level of air pollution,” says Rochelle Schneider, who researches the use of artificial intelligence in Earth observation at ESA. She is particularly interested in how satellite data can be used in healthcare.
Another natural event that satellite data can provide information about can have massive effects on human health: floods.
cholera and diarrhea
785 million people worldwide do not have access to clean water. For example those people who live at Lake Vembanad in the state of Kerala in India. With a length of around 100 km, Lake Vembanad is the second largest lake in the country. And a real mess.
The water, heavily polluted with heavy metals, pesticides and microplastics, is nevertheless a tourist attraction and the livelihood of many people. In 2018, a particularly heavy monsoon led to a flood of the century – 500 people died and over a million people lost their homes. Floods also often lead to so-called “waterborne diseases”.
In addition to cholera, diarrheal diseases caused by bacteria such as Escheria coli (E. coli) are the cause of death for around 1.5 million people a year. The spread of E. coli and the resulting diseases are strongly correlated with rainfall, says Manuela Grippa from Géosciences Environment Toulouse (GET) in France.
Together with researchers from Burkina Faso, Grippa used satellite data to estimate precipitation levels. In addition, the scientists examined collected water samples and evaluated epidemiological data on the spread of diarrheal diseases in the region.
Much knowledge, too little will?
‘Satellite data is particularly useful in regions where there are few other options for collecting health and environmental data,’ explains ESA’s Rochelle Schneider.
After two days at the Living Planet Symposium, Earth observation satellites strike me as extremely useful diagnostic tools, constantly monitoring and surveying the planet.
As with a patient whose heart attack may be predictable through close monitoring, the satellite data can provide valuable clues to impending disasters such as floods.
In order to be able to actually prevent the catastrophe, whether heart attack or flood, measures are necessary. In the case of the planet, these are primarily climate protection measures.
So whether there is actually a lack of knowledge and data to answer the question of how we can maintain a healthy planet worth living in for all people, or whether there is not much more political will to act – I did not receive a satisfactory answer to that at the Living Planet Symposium.