Event Coverage

When are satellite images most useful? When someone explains them

Monitoring data provide an unparalleled window onto the state of ecosystems, but only if they’re reliable and the meaning is clear.
“We are living in the most dramatic era of road expansion in human history ever”: Bill Laurance. Image: NASA

Related stories

Satellite and other data for monitoring the health of forests and other landscapes are getting better all the time – but transmitting that information clearly and effectively to decision-makers remains a challenge, according to experts from both science and policy.

“That’s something which we are trying to understand,” Christopher Martius, Principal Scientist for climate change at the Center for International Forestry Research (CIFOR), said during a panel of scientists and policymakers at the 2015 Global Landscapes Forum in Paris on 6 December.

It’s a question of both communication and scientific rigor, he added: “How [do we] increase the transparency and reliability of data?”

On the other side of the science–policy divide, decision makers say they need guidance about the messages hidden within those data.

“Policymakers … need to be further provided with more understanding of how to best use the models and how far we could rely on the models,” said Nur Masripatin, Director General for Climate Change with Indonesia’s Ministry of Environment and Forestry.


Bill Laurance, Director of the Centre for Tropical Environmental and Sustainability Science at James Cook University in Australia, offered a case study on the development of roads and infrastructure globally. Informed, purpose-driven decisions necessitate a better understanding of the knock-on effects of this type of development, Laurance said.

“We really, desperately need better data on roads,” he said. “It’s absolutely fundamental in everything we’re trying to do, with modeling road impacts, with understanding road impacts.”

Roads connect farmers to markets and are important for countries’ economic success. But they also open up new areas to hunting, deforestation, and resource extraction, which can be devastating to the environment.

We direly need much more strategic and proactive planning of where roads should and shouldn’t go.

Bill Laurance

And that trend is increasing.

Laurance pointed to “this incredible tsunami of road and infrastructure expansion happening everywhere, penetrating may of the world’s last wild places.”

“We are really living in the most dramatic era of road – and also all kinds of infrastructure – expansion in human history ever,” he added. “It’s been projected by the middle part of this century, we’re going to see something like 25 million kilometers of new paved roads” – enough for about 625 round-the-world trips.

If this sort of development isn’t well thought out, it could be devastating, he said.

“We direly need, living in this time of this tsunami, much more strategic and proactive planning of where roads should go and where they shouldn’t go,” Laurance said.

“Because if we don’t, we’re going to be in trouble.”

Laurance and his colleagues have studied this topic extensively. They recently published a paper in the journal Current Biology, in which they examined 33 “development corridors” either planned or underway in Africa. Typically, these spaces are built around a transportation conduit – a road or railway – and their designed to stimulate the economy by connecting markets and encouraging job-generating investment in sectors such as mining.

The trouble is, they don’t always maximize economic benefits while minimizing impacts on the landscape.

Six of the 33 are “flat-out bad ideas,” Laurance said, often because they would involve the incursion of populations into lands that wouldn’t provide much in the way of agricultural benefits, but they would potentially disrupt environmentally valuable landscapes. Most of the others represent uneasy compromises between the benefits they will bring humans and the destruction of the environment they may cause and should be the subjects of further review, said Laurance.


One way to increase the reliability of data is with better technology. Bianca Hoersch, the Sentinel-2 Mission Manager with European Space Agency (ESA), explained that the Sentinel-2 satellites will provide scientists with “unprecedented data.”

By the end of the year, the ESA plans to have two satellites in orbit, Hoersch said. With a resolution of 10 meters, elements in the landscape like trees and houses will be clearly distinguishable.

Also, she said, “You can clearly distinguish any roads.”

Although some of the satellites in space provide better resolution, the Sentinel-2 satellites will be unmatched in their coverage of the landscape, she said, “covering almost 300 kilometers of swath” in their passage over the earth.

In fact, they will provide new data on the same area at the equator every five days.

Perhaps most exciting, she said, was that the data would be “freely and openly available to anyone”.

“The only thing you need is huge hard disks,” she added, “because the data is enormous.”


That transparency is another huge concern in getting this information into the hands of policy makers, the panelists agreed.

“In a democratic society, transparency is absolutely essential for the civil society to pressure the government to do things,” said Gilberto Câmara, Senior Researcher with the Earth Observation Directorate of the National Institute for Space Research in Brazil.

Policymakers need more understanding of how to best use the models and how far we could rely on the models.

Nur Masripatin

To ensure the political will is there to deal with these sorts of problems, the confidence, reliability and transparency of the data are critical in developing real-world solutions to issues such as climate change, poverty and forest degradation.

David Cooper, Deputy Executive Secretary of the Convention on Biological Diversity, summed up the importance of the discussion, saying that scientists need to ask themselves “how we can improve what we’re doing in this domain, reduce the uncertainties, [and] increase the confidence that policymakers and investors will need to make reality the role of forests in climate mitigation, climate adaptation, and in achieving the broader sustainable development goals.”

Copyright policy:
We want you to share Forests News content, which is licensed under Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0). This means you are free to redistribute our material for non-commercial purposes. All we ask is that you give Forests News appropriate credit and link to the original Forests News content, indicate if changes were made, and distribute your contributions under the same Creative Commons license. You must notify Forests News if you repost, reprint or reuse our materials by contacting forestsnews@cifor-icraf.org.