Over the past decade, space agencies have launched several Earth-observing satellites that monitor climate change, deforestation, ocean acidification, and other environmental crises linked to human activity. Despite the protests of critics like Ted Cruz, who thinks "NASA's core mission" should be centered on other planets, not our own, space scientists and conservationists have already made great scientific yields by partnering together and sharing data.
That said, there is a lot more work to be done to strengthen and streamline the Venn diagram between satellite operators and ecologists. Indeed, according to a new Nature comment by biodiversity specialists Andrew Skidmore and Nathalie Pettorelli, one of the biggest problems facing this fledgling partnership is simply communication.
"With global wildlife populations halved in just 40 years, there is a real urgency to identify variables that both capture key aspects of biodiversity change and can be monitored consistently and globally," Pettorelli said in a statement.
"Satellite remote sensing is crucial to getting long-term global coverage," said the authors in their piece. "But there is no agreement on how to translate these measurements into metrics that are relevant for biodiversity monitoring."
So while in theory, there is a wealth of information to be parsed between the satellite and conservation communities, in reality, important nuances are getting lost in translation. That's why researchers like Skidmore and Pettorelli have been working to establish a solid rubric on which this interdisciplinary research can depend.
This is challenging work because, as the authors note, biodiversity "is not measured in physical units, such as centimetres of precipitation or degrees of temperature." It is instead a complex web of interactions between energy, organisms, and habitat health. With that in mind, Skidmore and Pettorelli laid out the following ten potential variables to be adopted for space-down biodiversity analysis:
The team considers this to be a useful starting point rather than a definitive list, though some of the variables—like vegetation height—are definitely essential to accurate biodiversity measurements.
"[Vegetation height] is a key variable in allometric equations to calculate biomass, as well as for detecting deforestation and degradation, for example," Skidmore told me in an email. "Productivity as well as functional diversity can also be modeled from vegetation height."
A better system of metrics would also help to monitor animal biodiversity, in addition to habitat health as a whole. "There are case studies counting wildebeest in the savannah as well as penguins in Antarctica using high resolution imagery," Skidmore said. "As imagery becomes available with even finer resolution, the possibilities for direct detection of animals is increasing."
For Skidmore, Pettorelli, and their colleagues, the ultimate goal is to continue to develop a sophisticated satellite network that can constantly identify biodiversity trouble spots on Earth, and alert conservationists to respond as quickly as possible.
Whether it's excessive deforestation or evidence of animal poaching, remote-sensing teams will be watching and communicating with ground teams using a common scientific language, allowing for a much more efficient defense of Earth's dying ecosystems.
"Satellites can help deliver such information, and in ten years' time, global biodiversity monitoring from space could be a reality," said Pettorelli. "[B]ut only if ecologists and space agencies agree on a priority list of satellite-based data that is essential for tracking changes in biodiversity."