Kudzu: It's worse than you thought. The invasive plant now covers more than 7 million acres in the United States, mostly in the Southeast but not limited to there. Besides overrunning trees as it spreads like wildfire, the vine also brings another danger: In a study in the Proceedings of the National Academy of Sciences, Jonathan Hickman sounds the alarm that kudzu could cause a spike in ozone, polluting the air. Ozone, of course, is a good thing when it's high in our atmosphere, blocking some of the sun's harmful radiation. But down on the surface of the planet, ozone isn't such a good thing. It can cause respiratory problems in people and harm plants' ability to absorb carbon dioxide; it also is a major constituent of smog.
Kudzu's contribution to ozone levels works like this: Like other members of the pea family, or legumes, Kudzu grabs nitrogen from the ...