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San Diego Researchers Looking To Grow A Climate Solution
Monday, December 14, 2020
Salk Research Institute Greenhouse manager Makenna Hopwood opened a door to what she jokingly calls "the meat locker."
“Alright, here we are,” Hopwood said as she pointed to the ceiling.
Bags of drying plants, both stalks and roots, hang from the ceiling, prompting the comparison to a slaughterhouse meat cooler. But, of course, the hanging carcasses here are plants.
“These have all been root-washed and processed and they’ve been drying for about a week,” Hopwood said. “Depending on the crop, we’ll hang dry them for two to three weeks, and then we’ll throw them in the plant dryer over for a day or two. And then we’ll do our biomass weights.”
This is the final stop for plants raised in this Salk greenhouse before they head to the lab.
Hopwood manages a constant cycle of planting, growing and harvesting plants here.
“Some plants don’t really like to be watered from the top,” Hopwood said as she drenched the bottom of a plant tray. “And these ones are really sensitive, so if they have soil that gets tossed into the middle of the plant (by sprayed water), they won’t produce their flower, so we have to bottom water them or mist them very lightly, which just takes a really long time.”
Some of these plants grow fast, from seed to harvest, in a few months.
Others are crop plants like corn, soybeans and wheat. Add in sorghum, rice and canola and that represents most of the world’s popular food crops.
Total planted acreage of those six crops could cover all the land in India.
Salk researchers are working to make the plants better.
“One of the biggest challenges, we think, and the biggest threat for humanity is the climate crisis,” said Wolfgang Busch, a researcher at the Salk Institute for Biological Studies.
Busch wants to find ways to make those widely used plants a lot better at moving carbon from the air and storing it deeper in the ground.
He is using millions of dollars in grants to develop longer and deeper root systems. That will help them survive in a hotter dryer climate but he also wants the plants to absorb more of the carbon that the burning of fossil fuels spews into the air.
“And we’re trying to find mechanisms,” Busch said. “Genetic recipes to actually make better plants or make plants better at storing larger amounts of carbon underground longer in the soil.”
Finding the right combination of gene manipulation, breeding, and then transferring desirable traits from other plants could make those six crops better at carbon sequestration.
It is a short-term answer to a long-term problem.
“There are currently no really scalable methods to draw down carbon dioxide, except plants,” Busch said. “So if you think about this in the long run this technology will enable carbon drawdown that is really urgently needed to get back to carbon dioxide levels in the atmosphere that are safe for us.”
But the clock is ticking.
The planet’s average temperature continues to climb at dramatic rates and it will still be about five years before he’s likely to develop the plants that he’s confident will help.
Getting lots of those plants in the ground could take 15 years, heightening the urgency.
But scientists are still optimistic.
“I think we can, but we’re really right on the edge,” said Joanne Chory, the lead researcher on Salk’s Harnessing Plant’s Initiative.
Chory points out that temperatures are rising because people push more carbon dioxide into the air than what the planet can account for.
She understands the urgency, but remains hopeful.
“You don’t have to fix everything,” Chory said. “You only have to get those 18 gigatons that the Earth can’t deal with. That’s a small part of what plants push around on a regular seasonal basis. They’re pushing around more like 800 gigatons.”
Plants can pull about four gigatons of that extra carbon out of the air and bury it in the soil, according to Chory.
Building out more renewable energy and making cars electric could help too, but those transitions will take time. Chory thinks developing plants that can move more carbon out of plant sugars and into non-biodegradable polymers buried in deep roots could buy some time until other solutions come along.
Meanwhile, McKenna Hopwood is spending that time trying to help grow the solution in that Salk Greenhouse in San Diego. Grow, harvest, weigh and repeat.
“So I’ll take some wheat right here, it's been growing a little long,” Hopwood said as she potted a little sprig of wheat. “Then, you just take this guy, transplant it in, and cover it with our substrate. There you go.”
Researchers are confident the science will help them improve the plants, but they do not share that optimism about governments and farmers.
They will have to come together to implement the solution before the climate gets too warm.
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