A satellite will 'weigh' the Earth's forests from space in 2021

How much junk is in the trunks?

A satellite will weigh the Earth s forests from space in 2021

Earth scientists are working on a revolutionary radar system that will be able to 'weigh' the world's forests, which they hope to launch into space in 2021.

The mission, which is called BIOMASS and is being led by Shaun Quegan from the University of Sheffield, will see the radar installed on a satellite and blasted into orbit. There, it will gather the data to create a three-dimensional map of the Earth's forests.

"The study will essentially weigh forests – it will tell us their weight and height, and we will be able to see how they are changing over time," said Quegan.

Scarcity of data

Currently, those measurements are made from the ground - which is tricky to do in remote regions, and suffers from scarcity of data. The radar, which will operate at a wavelength of 70 centimeters, will be able to gather vastly more data as it circles the globe, with the results checked and confirmed by ground data.

Quegan added: "It will give us unprecedented insight into the structure of forests across the world and how changes in forests, both losses from deforestation and gains due to regrowth and reforestation, are affecting the amount of carbon dioxide going into our atmosphere."

Alongside its primary mission, the satellite will also provide information on the motion of ice sheets, the dynamics of the Earth's upper atmosphere, and what lies below the surface in arid regions. It will be built by Airbus UK.

Carbon cycles

The resulting information will give us a better understanding of how carbon cycles through the Earth's natural systems, as part of the fight against climate change. Countries will also be able to use it to negotiate the management of forests that cross borders.

The mission has already been delayed from an original launch date of 2019, but if all goes smoothly the satellite should launch in 2021 as the seventh mission in the European Space Agency's 'Earth Explorer' programme.

Before that, there's plenty of work to do - from calibrating the radar's measurements to figuring out how to combine its output with ground data.

"Understanding how the amount of living material – biomass – in our global forests changes over time is necessary for improving present and future assessments of the global carbon cycle, and therefore our climate," said Quegan.

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