Air in the (actual) Amazon shows how we're messing with climate

When researchers from the Pacific Northwest National Laboratory analyzed the atmosphere over the Amazon, they discovered a new baseline for how pure air can be — and how drastically we are changing it.

The Amazon rainforest covers over 2 million square miles of the South American landmass. It absorbs so much carbon and produces so much oxygen that scientists call it “the lungs of the Earth.” Now, researchers from Pacific Northwest National Laboratory in Richland, Washington, have encountered a bank of air so pure it changes our understanding of how clean the atmosphere can be. A team of researchers flew a small plane outfitted with specialized instruments over this section of the Amazon, capturing particles of air virtually unchanged from before the age of humans.  

And yet the Amazon is not empty of humans. Manaus, Brazil, a city of nearly 2 million people, lies in the heart of the rain forest. It generates its own plume of air — this one filled with the carbon and pollutants that show how modern civilization alters our atmosphere. The mission was to contrast human-affected and pristine air to create a new baseline for air quality before humans started affecting the atmosphere.

“The way [the] aircraft is moving is like time travel. You are outside the plume; you are before the industrial age. Then when it zigzags and goes into the plume, you get into polluted conditions. You are traveling back and forth through time,” said Earth systems scientist Dr. Manish Shrivastava.

Once an international team analyzed all the data from the pristine and polluted plumes, they discovered human pollution spurs the production of climate-changing particles known as aerosols much more quickly than previously thought. Beyond accelerating climate change, these particles have the potential to worsen human health all over the world. They can cause diseases of the heart, lungs and other organs.

Perhaps the longest-lasting impact of these new findings is the establishment of a new standard for how clean and pure air on Earth can be. This baseline can be used as a benchmark in research for years to come. “As human activities develop, we can look back at the Amazon and then we can see how much we have been changing it and how much we will continue to change it,” said Dr. Shirvastava.

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About the Authors & Contributors

Ted Alvarez

Ted Alvarez

Ted Alvarez is formerly an editor at Crosscut and KCTS 9 focused on science and the environment.