In a recent blog post, Bill Gates notes most greenhouse gas emissions come from electricity generation –25 percent. However, Mr. Gates also highlights that the agriculture sector is responsible for 24 percent of greenhouse gas emissions, nearly the same amount as electricity generation.
This, of course, includes a multitude of factors – livestock, field burning of crop residues, fuel use on farms, rice cultivation – but Mr. Gates focuses on an interesting component to ag emissions: soil.
Here’s a mind-blowing fact: there’s more carbon in soil than in the atmosphere and all plant life combined. That’s not a big deal when left to its own devices. But when soil gets disturbed—like it does when you convert a forest into cropland—all that stored carbon gets released into the atmosphere as carbon dioxide. That’s one reason why deforestation alone is responsible for 11 percent of all global greenhouse gas emissions. (Another reason is that forests and grasslands are natural carbon sinks. Clearing them reduces the planet’s capacity to remove carbon dioxide from the air.)
The microbes in soil can also create greenhouse gases when they come into contact with fertilizer. Synthetic fertilizers revolutionized how we feed the world, but they release a powerful greenhouse gas called nitrous oxide when broken down by those microbes. Natural fertilizers like manure aren’t any better, because they release greenhouse gases as they decompose.
Addressing emissions from agriculture is a challenge. We need to grow crops and raise livestock for the global food supply. Fortunately, there are companies creating biology-driven solutions to help reduce greenhouse gas emissions related to agriculture. Mr. Gates features one such company in his blog post:
I’m involved with a group called Breakthrough Energy Ventures that is backing a number of creative solutions to tackle the problem. Because every country and every culture approaches food production differently, there are a lot of different ways to do that.
Microscopic nitrogen factories that replace fertilizer: What if we could fertilize plants without releasing so much harmful nitrous oxide into the air? BEV is invested in a company called Pivot Bio that has genetically modified microbes to provide plants with the nitrogen they need without the excess greenhouse gases that synthetic alternatives produce.
A plant needs sun, water, carbon dioxide, and nitrogen to grow. Since plants don’t make their own nitrogen, fertilizer is used. While making and using fertilizer creates a lot of pollution, it is needed to meet the growing food demand. “If we stopped using fertilizer tomorrow, we wouldn’t be able to produce half of the world’s food supply. But there’s a possible replacement, and it lies in the soil beneath our feet,” said Karsten Temme, co-founder and CEO of Pivot Bio.
Mr. Temme is referring to microbes in the soil, which can also produce nitrogen for crops. Right now, dependence on fertilizer has caused such microbes to go into hibernation. Pivot Bio is reversing that. The company extracts microbes off the roots of seedlings and sequences the DNA in an effort to understand which microbes are baked into the plant’s genome to produce nitrogen. Pivot Bio turns those genes back on, and these microbes can make nitrogen again.
Pivot Bio’s revolutionary work has the potential to eliminate the conventional practice of applying nitrogen to soil through fertilizer, which will help reduce greenhouse gas emissions from agriculture. This is just one example of how biotechnology is generating innovative breakthroughs that can help address some of the world’s greatest challenges, such as climate change.