Fifty million years ago a small plant had a massive impact on the Earth’s climate by helping to remove carbon dioxide from the atmosphere. Scientists are now trying to learn more about the Azolla fern, and how it might help reduce man-made climate change.
When Azolla came to the rescue 50 million years ago, the Earth was much warmer than it is today, with dangerously high levels of greenhouse gases. The Arctic Ocean was a large hot lake, with tropical climatic conditions near the North Pole.
Because of the high levels of carbon dioxide in the atmosphere, the Azolla fern flourished, covering the entire Arctic Ocean like a giant mat. As successive growths of Azolla died and sank to the bottom over nearly a million-year period, they took carbon with them. This Arctic Azolla event was discovered during an expedition to the North Pole in 2004.
Atmospheric carbon dioxide levels dropped almost 50 percent during this period, leading to the change from a hothouse climate to Earth’s current climate with permanent ice at both poles.
Azolla can double in size in less than two days, needs no soil and can extract all the nitrogen it needs from the air. It is considered a “superorganism” — a plant that hosts microbes that convert atmospheric nitrogen to feed itself. Farmers in Asia have long used it as a companion plant that provides a natural, green fertilizer in rice fields.
Finding new uses for a miracle plant
Scientists around the world are seeking to unlock the secrets of Azolla, including Kathleen Pryer, a Duke University professor leading a crowdfunding effort to sequence Azolla’s genome.
In parts of the world, Azolla is considered an invasive species because it can form rapid blooms, crowding out other plants and reducing oxygen levels in the water.
But Azolla has massive green potential. In addition to its ability to draw in carbon, it also absorbs environmental pollutants like heavy metals and hydrocarbon compounds — a promising option to clean wastewater.
In addition to reducing the need for energy-intensive synthetic fertilizer, Azolla could also be used as livestock feed, in biofuels or as a way to control mosquitoes.
“This plant is so incredible at every level; I wouldn’t be surprised by just about anything we found out it was capable of,” one researcher said.