Satellites To Monitor Greenhouse Gases

New space-based tools are gearing up to curb greenhouse gases, and to understand what happens to carbon dioxide after it is emitted.

Satellite imagery is already used to monitor and curtail deforestation. But those images only capture the forest canopy. A new instrument will map the forest in three dimensions.

Aqua satellite - 3D renderThe instrument is called a Global Ecosystem Dynamics Investigation (GEDI) Lidar. It produces imagery using reflected laser light, the same way radar measures reflections of radio waves. It is slated for deployment on the International Space Station in early 2018.

Forests and oceans absorb about half of the carbon dioxide that human activities emit. But scientists don’t know exactly where and how that carbon dioxide is absorbed, or how much — or why — that absorption varies from year to year.

The Orbiting Carbon Observatory, or OCO-2, will help get a handle on those unknowns. The satellite-based instrument lets scientists visualize on a global scale where carbon dioxide is emitted and where it is taken up.

In the first year of data collection, Ott and colleagues were able to watch plants in the northern hemisphere suck carbon dioxide out of the atmosphere in the early spring.

One tool will help monitor deforestation and help enforce agreements to stop it. The other gives scientists the most detailed information ever on where carbon dioxide is coming from and where it is going.

Deforestation accounts for between 10 and 15 percent of global greenhouse gas emissions. The draft Paris agreement backs programs that give financial rewards to successful efforts to reduce emissions from deforestation and forest degradation, programs known as REDD.