For the handful of people who get the chance to observe Earth from space, the impact is often profound. Called the “overview effect”, astronauts report being deeply moved by the experience, as the planet’s fragility and beauty became clear. Others, such as the actor William Shatner, said they were overcome with grief.
Now, scientists are proposing the creation of a new system that they hope will use the view from space to transform our understanding of Earth’s changing ecology and its complex systems.
By combining satellite data and imagery with on-the-ground technologies such as camera traps, acoustic monitoring and DNA barcoding in every country on Earth, scientists say the creation of a new multibillion international scheme would allow countries to effectively track the health of the planet and safeguard food, water and material supplies for billions of people.
In 2022, governments pledged to transform their relationship with nature by the end of the decade. From halting extinctions caused by human behaviour to restoring nearly a third of the planet’s degraded ecosystems, countries signed up to 23 targets to stop the rapid decline of life on Earth.
But a growing number of scientists warn that data about the health of the planet’s seas, soils, forests and species are so flawed, it will be impossible to know if we have been successful at meeting the agreed-upon targets. Despite major advances in monitoring the climate, information on the Earth’s biodiversity is comparatively poor, they say. To overcome the issue, researchers have proposed the creation of a new system to monitor the biosphere akin to how humans monitor the weather, regularly “taking the pulse of the planet”.
Canada, Colombia and several European nations are among the countries developing their own biodiversity observation networks – known as BONs – which researchers say should be combined into a global observation system. A BON system brings together raw data on seas, soils, forests and species to give an overview of a nation’s biodiversity health – which could then be combined at a planetary level.
“The uncertainty in our knowledge of where biodiversity is changing is so great that even if we achieve the goals, we wouldn’t be able to measure them,” says Andrew Gonzalez, a professor in conservation biology at the University of McGill, who co-chairs GEO BON, a global biodiversity observation network aiming to make the initiative a reality.
“We wouldn’t even know if we’d hit the target. I’m not sure that everybody’s quite ready for that conclusion but that’s the stark reality,” he says. “If you can’t measure it, you can’t manage it, as the saying goes. And if you can’t predict it, you can’t protect it. These things really matter.”
This year, the world’s space agencies are coming together to improve their biodiversity monitoring. There are various limitations of the current data, say researchers. Analysis of 742m records of nearly 375,000 species in 2021 found widespread gaps and biases: just 6.74% of the planet has been sampled, with high elevations and deep seas particularly unknown. Some of the biggest gaps were in the tropics, despite these areas being home to large swathes of life. Europe, the US, Australia and South Africa accounted for 82% of all records, and more than half of records focused on less than 2% of known species.
The data gaps are not limited to animals. In 2023, Kew Gardens identified 32 planet “dark spots” – including Fiji, New Guinea and Madagascar – that are known to be rich in plant biodiversity but have poor data records. Fourteen dark spots were in the Asia-tropical region, six were in the Asia-temperate region, nine in South America and two in Africa. There was one in North America.
Alice Hughes, an associate professor at the University of Hong Kong, says the poor data coverage means that places like the Democratic Republic of the Congo, which has the largest share of the second-biggest rainforest on Earth – home to huge numbers of species – are poorly understood despite being under significant threat. Geospatial data can be used to monitor loss from spaces, says Hughes, but new technologies such as eDNA and other methods have opened up new ways to monitor ecosystem health.
Other techniques, such as acoustic monitoring and DNA barcoding allow better understanding of ecosystems and identify some of the millions of species yet to be discovered. Innovations in scanning technologies enable researchers to check an entire forest for disease and identify species distributions. But scientists say there is still more to be done to look at Earth’s systems as a whole.
“If you go to a doctor, you don’t want them to just look at you and say, ‘yeah, you look healthy’ or, ‘you look a bit pale’,” says Hughes. “They take measurements. There are many different ways to use this data but it would basically allow us to take the pulse of the planet.”
Maria Azeredo de Dornelas, a professor of biology at the University of St Andrews, says: “We need a bigger observation system that allows us to measure biodiversity like we measure the weather. We probably don’t need it as frequently as the weather but we do need to do it.
“There is the potential to do this really well. It would need international cooperation because it’s not the kind of thing that one country or even continent can do. The planet’s biodiversity doesn’t really care about political borders.”
