With satellites we look at landscapes, not pixels

November 29, 2016

By Leona Liu, originally published at CIFOR’s Forests News

Matt Hansen is a professor in the Geographical Sciences Department at the University of Maryland. He spoke on the sidelines of the Global Landscapes Forum about what technology means for the global climate agenda.

How is technology helping with the climate change agenda?

Remote sensing by definition is the idea that you can say something about an object, which you can’t touch. So it’s the same thing as our eyes. We can integrate all this information across our field of view and fill in the gaps.

Traditionally, with forestry, they have plots every kilometers or so, and those plots are labor-intensive. They cost a lot of money and it’s not easy to redo them repeatedly.

But when you have this image that just goes across the entire landscape and you can repeatedly image it, you get this information on how this land is changing and we are able to track deforestation rates and what kind of land use has replaced the forest. We can track almost anything on the land’s surface- urbanization, inundation, agriculture, and forest. So it’s this fantastic tool that feeds into a big part of climate change, which is the land use component.

You’ve talked about some of the opportunities of this technology. What are some of its limitations today?

I think one of the big things is to not overstate capabilities. To not say that it can do everything that a user might want or expect. We have to meet somewhere in the middle.

With remote sensing, we can’t see biomass directly, it’s a highly modeled variable, and we don’t see forest-associated species very easily. So there’s a lot of things we can’t do.

That doesn’t mean it’s not useful, it just means that either we can use what we can do to solve the same problem, understand what it means and use it appropriately, or we can integrate it with data.

How has this technology entered into policymaking? Is it being used to its full potential?

I think the biggest trick from a policy standpoint is that when this whole thing started, in regards to REDD+, policy was a bit ahead of the science when it came to the methods.

What I mean by that is Northern countries like the U.S. don’t do annual forest change mapping. No country does that. And at the same time, the entire North is trying to report capacity to the South. But what capacity are you reporting? We’ve never done it.

So there’s a mismatch in the aspiration in policy. We’re playing catch-up now. I think we do have the methods that can be operationalized to support policy. We have to get them into the hands of the people who are responsible for each of the national reports [related to NDCs] and I think we’re ready.

Why were you motivated to participate in the Global Landscapes Forum?

I like it because it has a very diverse user base. You’re talking about the technical practitioners, the governments, and the civil society. Landscape is an integrating concept.

Even with satellites, you don’t look at a single pixel- that would make no sense. You wouldn’t even look at a forest patch. You need to back up. It only makes sense when you look at it on a landscape scale. At the landscape scale, all these parties are interested, so you have a nice multi-stakeholder framework. It makes a lot of sense.

*This is part of a series of interviews from the 2016 Global Landscapes Forum: Climate Action for Sustainable Development in Marrakesh, Morocco, a key event under the CGIAR Research Program on Forests, Trees and Agroforestry.