Plants that received extra carbon dioxide didn’t grow more or get greenerLeave a Comment
By Seth Borenstein and Alicia Chang, AP science writers LOS ANGELES — Sep 5, 2016, 3:06 PM ET
In the course of a 17-year experiment on more than 1 million plants, scientists put future global warming to a real world test — growing California flowers and grasslands with extra heat, carbon dioxide and nitrogen to mimic a not-so-distant, hotter future. The results, simulating a post-2050 world, aren’t pretty. And they contradict those who insist that because plants like carbon dioxide — the main heat-trapping gas spewed by the burning of fossil fuels — climate change isn’t so bad, and will result in a greener Earth. At least in the California ecosystem, the plants that received extra carbon dioxide, as well as those that got extra warmth, didn’t grow more or get greener. They also didn’t remove the pollution and store more of it in the soil, said study author Chris Field, director of the Stanford Woods Institute for the Environment. Plant growth tended to decline with rising temperatures…..
….Only the extra nitrogen — a byproduct of diesel engines and ammonia used as fertilizer — made plants greener. Field, whose study appears Monday in the journal Proceedings of the National Academy of Sciences, theorizes that there’s a limit to how much carbon dioxide plants can use. Outside scientists praised the long-running experiment.…”This study clearly demonstrates that as temperatures continue to rise due to climate change, grassland ecosystems will likely not be able to tolerate the higher temperatures and increased drought stress,” Boston University biologist Richard Primack emailed….
Nonlinear, interacting responses to climate limit grassland production under global change
Kai Zhu, doi: 10.1073/pnas.1606734113