Marginal improvements to agricultural soils around the world would store enough carbon to keep the world within 1.5C of global heating, new research suggests.
Farming techniques that improve long-term fertility and yields can also help to store more carbon in soils but are often ignored in favour of intensive techniques using large amounts of artificial fertiliser, much of it wasted, that can increase greenhouse gas emissions.
Using better farming techniques to store 1% more carbon in about half of the world’s agricultural soils would be enough to absorb about 31 gigatonnes of carbon dioxide a year, according to new data. That amount is not far off the 32 gigatonnes gap between current planned emissions reduction globally per year and the amount of carbon that must be cut by 2030 to stay within 1.5C.
The estimates were carried out by Jacqueline McGlade, the former chief scientist at the UN environment programme and former executive director of the European Environment Agency. She found that storing more carbon in the top 30cm of agricultural soils would be feasible in many regions where soils are currently degraded.
McGlade now leads a commercial organisation that sells soil data to farmers. Downforce Technologies uses publicly available global data, satellite images and lidar to assess in detail how much carbon is stored in soils, which can now be done down to the level of individual fields.
“Outside the farming sector, people do not understand how important soils are to the climate,” said McGlade. “Changing farming could make soils carbon negative, making them absorb carbon, and reducing the cost of farming.”
She said farmers could face a short-term cost while they changed their methods, away from the overuse of artificial fertiliser, but after a transition period of two to three years their yields would improve and their soils would be much healthier.
She estimated it would cost about $1m (£790,000) to restore 40,000 hectares (99,000 acres) of what is currently badly degraded farmland in Kenya, an area that is home to about 300,000 people.
Downforce data could also allow farmers to sell carbon credits based on how much additional carbon dioxide their fields are absorbing. Soil has long been known to be one of Earth’s biggest stores of carbon, but until now it has not been possible to examine in detail how much carbon soils in particular areas are locking up and how much they are emitting. About 40% of the world’s farmland is now degraded, according to UN estimates.
Carbon dioxide removal, the name given to a suite of technologies and techniques that increase the uptake of carbon dioxide from the air and sequester the carbon in some form, is an increasing area of interest, as the world slips closer to the critical threshold of 1.5C of global heating above pre-industrial levels.
Arable farmers could sequester more carbon within their soils by changing their crop rotation, planting cover crops such as clover, or using direct drilling, which allows crops to be planted without the need for ploughing. Livestock farmers could improve their soils by growing more native grasses.
Hedgerows also help to sequester carbon in the soil, because they have large underground networks of mycorrhizal fungi and microbes that can extend metres into the field. Farmers have spent decades removing hedgerows to make intensive farming easier, but restoring them, and maintaining existing hedgerows, would improve biodiversity, reduce the erosion of topsoil, and help to stop harmful agricultural runoff, which is a key polluter of rivers.
I am conflicted about this.
On one hand, yay, some semblance of hope.
On the other, many will just see this as another way to skirt around limititng their carbon emissions because we can fix it later.
And, of course, its unlikely that many will even try doing this because why save the planet when we could increase profits by 2.3% over the next quarter by not doing it?
That’s exactly what it does.
We are releasing millions of years of sequestered carbon in a few hundred years. CO2 levels are spiking rapidly.
Carbon sequestration in agriculture is also a pipe dream. Covercrops reduce the depletion of soil carbon. They are not shown to increase the levels. Only the addition of compost/manure from outside sources is shown to increase soil carbon to a point. However repeated applications are required to increase and maintain the percentage. As soon as you stop adding external carbon sources the numbers fall back down.
The best source of carbon sequestration is in native conserved ecosystems. If we want to sequester carbon we need to eliminate our archaic agricultural practices. Our single most environmentally damaging activity is agriculture. We have to minimize its impact on the planet.
One change could reduce our land needs by as much as 50%: Ban all dryland crop production and expand our irrigation systems.
Irrigated ground produces 2x to 10x more/ha. Migrate to protected culture (greenhouse, high tunnels, screen houses etc.) for up to 20x/ha production.
So I work in ag-tech and esg, and yeah the profit aspect is something we are all concerned about. That said, my group specifically is working with a few larger government organizations and nfps in the US to incentivize growers to focus on carbon sequestration by paying them a little extra per acre if they can prove they are implementing the changes laid out in OP. So far the growers are really keen on it.
I’m being intentionally vague as to not dox myself or the company I work with as this is all still very, very alpha.
We will literally do everything and anything but limit our carbon footprint.
Agreed, it doesn’t have to be the way it is
It will be ignored by industry, just like all the rest of the suggestions for the last 30 years from scientists. Profits come first, worry about the environment later (never).
You’re probably not wrong
Farmers are on a runaway debt of soil sustainability trying to keep up with demand. With long term in mind, each acre of farmland is capable of producing way more than it currently is, but people demand the food now, this season. Because you tilled last season, because you planted crops that need more nutrients because thats what consumers demanded, you depleted nutrients in the soil, you killed the microbiome that replenishes those nutrients, the crop consumers demand this season wont grow unless you artificially add nutrients back in and till them back into the soil. The soil will be in even worse shape next season, and there will be even more people to feed. And each passing year the crops still end up less nutritious than the last.
But this is a problem with another solution available, growing your own food with healthy soil in mind. Taking demand away from farmers. Honestly I wish people better understood the potential their own land has. Just try growing some beans, very easy to grow, quick to produce, and a great introduction to soil fixing plants, their roots attract bacteria that convert air nitrogen into bio available nitrogen. you can learn about the importance of perennials in drawing up deeper nutrients and creating a larger soil microbiome, cover crops for retaining moisture and protecting your soil from the sun, composting as an amazing way to sequester carbon yourself and get more free nutrients. All of these are things modern farmers are missing out on from their soil debt.
Farming has changed since the 1920s. Tilling has been out of style for decades now.
How your grandma did her garden is not good for the soil…sure plant one, but first put aside your ignorance about how modern farms work and do it right. (Finding good information us hard, garden magazines last I.checked were full of misinformation that isn’t backed by modern research)
Have any sites you would recommend for modernized home gardens?
Iowa state university has some small farmer info that is useful, but they are specific to the iowa climate (I live in iowa so this is good for me), but they only publish a small amount, most of what they do is focuses on large farms (in part because that is who listens). I suspect your area also has a research university with an ag focus.
I have had some success reading between the lines of their large farm focused things as well. Whoever it doesn’t make sense for a home garden to grow corn, corn likes large fields and doesn’t do as well in small gardens. I think wheat is similar (nobody grows wheat in iowa so I don’t know much about it)
It’s perfectly fine to grow crops in a home garden if done right. It’s a lot of work if you want to eat bread, cakes, brew beer, and so on, all at the same time obviously. Monoculture is never the right thing to do in terms of sustainability. Just watch nature do it’s work. You won’t find monoculture in any sustainable ecosystem.
No, tilling is definitely still the norm, and soil is still degrading with decreasing nutritional value of crops each year.
I cannot tell where you live from your profile. Different parts of the world have different situations, at least where I live (Iowa - major farming state) plowing is not common. There are other types of tilling, but they don’t degrade the soil as backed by real research.
so it’s changed from we havent been tilling for decades, to it’s a different kind of tilling. It’s tilling, it’s tearing up the root system and exposing the microbiome to dry air and sunlight. You’ve seen the dirt, it’s dead clay on those fields.
But here is the thing, it doesn’t tear up the root system. It just loosens the soil. Roots remain on place. Modern ag is a.wonder backed by real science. It is building up the soil (about 1mm per year, sounds slow but is fast on a geological timeline)
Modern ag is chemical fertilizer runoff and decreasing vitamins and minerals in produce.
But this is a problem with another solution available, growing your own food with healthy soil in mind. Taking demand away from farmers.
How do you propose people in apartments grow enough food to live off of?
You can’t. Even if you have a home, unless you own a lot of land near it, but can’t grow enough food to live off of it. Even if you had, the moment you have a problem (diseases, droughts, floods, too much sun, too little sun… etc) you are fucked.
I live in a small apartment and I have peppes and some small tomatoes plants, plus lots of herbs. You cannot really grow anything close to something you can live for. If your apartment is super large, you could have a hydroponics room, which would give you lots of option for reliable food, but it’s very energy intensive so it’s not really ecological unless you happen to have solar panels or something, in which case you probably aren’t in an apartment in the first place.
I like farming and worked a lot of it with my grandfather when I was a child and still help my family with it. But people don’t really know what farming is like, especially modern farming. Some people have really ideallized versions of what its like.
I dont get people with the logic of “this medicine reduces cases of this deadly disease by 50%, but its not 100% so its pointless and no one should take it”
Because it introduces a whole lot of new issues. People could make things so much worse. IMHO the real alternative is, if you have actual land, is to put native plants. That will help the ecosystem, retain water, attract life etc and all that is better than random farming.
If this is actually responding to what i wrote youre a lunatic condemning sick people to death
… Im not sure if I follow your interpretation.
All Im saying is that people doing farming without knowledge is not a solution and they can easily make soil worse, and if they want to contribute, they can do better by planting native flora.
I dont think you read what I wrote, about a medicine that cures 50% of all cases of a deadly disease. Do you get what that means? That’s saving people that would have died. But there are times where people have the logic that because it doesnt cure all of the cases, we should toss out that medicine and let all of them die.
Im talking about growing food for yourself. And you’re dismissing it, because “you cant grow enough to live off of”. Any amount of food that you grow is a benefit. You dont have to grow enough to live off of, but every bit that you do grow is still that amount less demand on these overworked farm fields
That was basically my point, but you put it a lot better.
I didnt propose it, this is for people with lawns
Then let’s go. I’m giving my share to bridge the income cut in the transition period.
Perennial crops of corn, wheat, rice and sorghum exist already. The land institute should win the Nobel peace prize. Look it up.
