At 5:56 a.m. EDT on Tuesday, NASA will launch its first satellite dedicated exclusively to measuring carbon dioxide all around the globe.
The data from the Orbiting Carbon Observatory-2 (OCO-2) will be extremely precise—the instrument will survey only one square mile of the Earth at a time, to avoid clouds. The instrument will take about a million individual measurements every day, of which 100,000 are expected to be useful. They will track CO2 as it’s emitted from sources like tailpipes, refineries and smokestacks, and will watch as the gas is absorbed into the ocean and taken up by trees and plants.
The hope is that, by observing how much CO2 is being absorbed into the oceans and land, scientists will be able to precisely predict how much CO2 will be on Earth 50 years from now, and where the CO2 will be stored. The implications of that knowledge are vast: It could mean predicting how crop yields will be like in specific agricultural regions when CO2 levels rise, or which forests will carry the burden of CO2 absorption.
As plants grow, they bring in blue light, and they re-emit yellow and red light in a process known as “solar induced fluorescence.” The OCO-2 will be able to see the light emitted from plants as they grow, and use that to measure how successful plants in certain regions are at absorbing CO2.
“Suddenly we could have a new, direct measure of how productive [certain] food-growing areas are going to be,” Michael Gunson, OCO-2 project scientist, says in a NASA video explaining the mission. “The two in combination—[measuring] the carbon dioxide in the atmosphere, and an indication of how effective plants are in taking CO2 out of the atmosphere—it’s just an impossibly brilliant combination.”
Carbon dioxide is the primary driver of climate change. Around 40 billion tons of it is released into the atmosphere every year due to human activities, or around 5.5 tons per person on Earth. In the past 14 years, the average level of carbon dioxide in the atmosphere has gone from 364 parts per million to nearly 400 ppm annually in recent years, which is unprecedented in Earth’s recent history. This June is set to be the third straight month with CO2 levels above 400 ppm, which is also a first. The current rate of increase is more than double the rate of increase in the 1960s.
Half of the CO2 that is emitted into the atmosphere remains there, while the other half is split up: one quarter is absorbed by the oceans, and the other quarter by the soil and forests. But no one knows for sure where exactly it is absorbed or at what rate.
“These are things we clearly have to start understanding if we want to actually manage the carbon dioxide buildup in our atmosphere,” said David Crisp, the science team leader of OCO-2.