Sep 26, 2023 - Science

Satellites are revolutionizing the way we see deforestation on Earth

Illustration of a satellite dish with the dish section made out of a tree stump showing the tree's rings.

Illustration: Aïda Amer/Axios

Powerful space-based sensors and tools are monitoring deforestation around the world in close to real time, arming companies, nongovernmental organizations and governments with data to combat the growing problem.

Why it matters: Deforestation, which can contribute to climate change and habitat loss, is a particularly thorny problem to tackle on Earth because it typically happens in remote areas and is difficult to track from the ground.

  • "These are huge areas, and we know that forests are critically important for mitigating climate change, for safeguarding biodiversity and also for local livelihoods in many cases," Mikaela Weisse, director of Global Forest Watch, tells Axios.
  • Observing Earth from space makes tracking easier, giving those enforcing the laws on the ground strong evidence that illegal logging and other activities are occurring.

Driving the news: The company CTrees just launched a new portal called the Land Use Change Alert (LUCA) system that can inform users when deforestation and other "degradation" events are spotted globally using synthetic aperture radar, which cuts through cloud cover that has hampered other efforts at times.

  • Right now, LUCA can alert users to these events on about a biweekly basis.
  • Once the NISAR satellite — an Earth-observing mission from the U.S. and India — comes online next year, however, it should allow the tool to make alerts available in less than a week, Sassan Saatchi, co-founder and CEO of CTrees, tells Axios.

Zoom in: Big data analytics has also revolutionized how satellite data can be used to understand what's happening with forests on Earth.

  • "In the past 10, 15 years, there has been a major shift in terms of our capability. We look at hundreds of terabytes of data in order to do this," Saatchi said.
  • That analytical power has sped up processing times and made it easier to get more actionable information from huge amounts of data.

And getting that information into the hands of people on the ground quickly has been shown to help slow deforestation.

  • A study from Global Forest Watch and others published in the Proceedings of the National Academies of Sciences in 2021 showed that Indigenous communities in Peru that used alerts powered by satellite data saw deforestation decrease by 52% in one year.

Between the lines: These types of systems can also be crucial for those trying to track and understand how the climate is changing.

  • Forests are a major carbon sink, so when more trees are cut down, more of that carbon typically stored in these forests is released as greenhouse gases.
  • "We need to quantify the carbon in a lot of forests globally, and we need to quantify how this carbon is changing and what are the drivers of the change. For any mitigation to really work, you need to know not only the quantity but also the ways that quantity changes and how you want to stop it," Saatchi said.

Yes, but: Having the data to understand when and where deforestation is happening is only part of the battle.

  • Acting on it requires local governments and municipalities to have access to clear, understandable datasets, Weisse said.
  • "We also do quite a bit of work with local and Indigenous communities as well either directly or through partners to train how those communities can benefit from this kind of data and in managing their lands," Weisse said.

What to watch: Other organizations are working to develop systems that would predict areas where deforestation might occur.

  • The World Wide Fund for Nature and Deloitte are developing an advanced AI algorithm to figure out how likely deforestation is in any area based on geospatial data that tells researchers where deforestation is happening now, how easy it might be to transport logs and other factors, including the nearest palm oil processing mill.
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