The earth-shattering story of how soil can end climate crisis

Preventing the destructive warming of our planet will be dirty work - but someone has to do it, says Kathriona Devereux
The earth-shattering story of how soil can end climate crisis

The world’s soils contain 1,500 billion tonnes of carbon in the form of organic material, more than all the vegetation on the planet

I JUST read a fascinating book called Wilding by the appropriately named author Isabella Tree.

It is a chronicle of her family’s effort to abandon conventional intensive farming and hand 3,500 acres of land at Knepp estate in west Sussex, England, back to nature.

Reading it created so many ambivalent feelings; on one page feelings of depression at the plummeting numbers of wildlife and the near extinction of creatures such as the nightingale and turtle dove. On the next page soaring hope at the regenerative power of nature and how, after a few seasons of benign neglect, Knepp became a haven and sanctuary for rare species such as peregrine falcons, purple emperor butterflies and illusive dung beetles.

The key to this pioneering wilding project was to introduce hardy free-roaming grazing animals onto the land.

These animals, such as Exmoor ponies, English longhorns and Tamworth pigs, are left to wander the acres, untended by humans. Their grazing keeps vegetation in balance, their rootling disturbs the ground,providing ideal conditions for wildflowers and wildlife, and their excrement provides nourishment for the important dung beetle and others.

They have stimulated new habitats so now the once sterile land is heaving with life and biodiversity. The transformation happened over a 15 year period and is ongoing.

The owners of Knepp now earn an income through eco-tourism and conservation grants, and from producing wild range meat, instead of making financial losses with intensive farming, requiring heavy machinery and heavy use of fertilisers.

Overall, Wilding is a story of hope and Knepp estate is a leading light in conservation circles, demonstrating that if humans get out of the way, nature can restore itself beautifully.

One of the most interesting chapters was about soil and the critical status of this most precious substances that humans rely on for the basics of life — air, food and water. About a quarter of all living species live in our soils (e.g. fungi, bacteria and invertebrates) and they play a crucial role in the regulation of nature and ecosystems.

Scientists are only beginning to unpick the intricacies of soil and the millions of microbes, fungi and other organisms in a material that is often overlooked as mere dirt!

I have had an interest in the science of soil since I met scientists at the European Soil Data Centre in Ispra, Italy, a few years ago, and learned about its complexity and the beneficial types of bacteria, mycorrhizal fungi, nematodes and other living organisms that support life, enable plant growth, capture carbon, and regulate water and air quality.

I was shocked then to learn how global soil health is degraded due to erosion, chemical pollution, compaction and other human influences, and how UN scientists have warned of a decline in global soil fertility.

A few years ago, we dedicated a whole episode of RTÉ’s 10 Things to Know About... to the topic of soil and I learned about the incredible micro-biology of soil. There are more organisms in one teaspoon of healthy soil than there are people on earth, and healthy soil contains about five million worms per hectare.

In the same way humans have a symbiotic microbiome in our bodies that is important to our overall health, soil also has its own microbiome that scientists are only beginning to understand.

Reading Wilding introduced me to a soil ingredient that I had never heard of — glomalin. Only discovered in 1996 by a U.S soil scientist, glomalin, is called the “superglue of soil” by helping to aggregate particles of sand, clay, and organic matter into the familiar material that farmers and gardeners crumble through their fingers.

Glomalin is an important component in soil’s ability to capture carbon. The world’s soils contain 1,500 billion tonnes of carbon in the form of organic material, more than all the vegetation on the planet, and soil scientists believe that returning unproductive agricultural land to permanent pasture, as well as restoring the world’s five billion hectares of degraded grasslands, would lower greenhouse gas concentrations in the atmosphere considerably.

Wilding concludes with a quote from famous conservationist Aldo Leopold: “One of the penalties of an ecological education is that one lives alone in a world of wounds.”

The more we open our eyes and learn about the natural world, the more we see its damage and destruction.

Solving the climate and ecological crisis can seem insurmountable at times, but the publication of the Government’s Climate Action and Low Carbon Development Bill was good news for those of us who worry about what the future holds for our children.

The Government has committed to halving Ireland’s greenhouse gas emissions in the next ten years and achieving a net-zero carbon society and economy by 2050. The key to resolving the climate crisis is to stop emissions of carbon dioxide to the atmosphere and a dramatic drop is required to halt global warming.

Scientists measure atmospheric carbon dioxide in parts per million and the latest weekly reading by the National Oceanic and Atmospheric Administration (NOAA) is 417.73ppm. This time last year that number was 414.52pm and ten years ago it was 392.63ppm.

Scientists consider 350ppm to be a safe level and 450ppm the level that will trigger extreme weather events, global warming in excess of 2Cm and irreversible climate change.

In tandem with stopping emissions, we also need to suck carbon dioxide out of the atmosphere quickly.

Handing unproductive and degraded land back to nature (and rewarding landowners for doing so) will be an important tool in fixing the climate and biodiversity crisis.

Let soil and nature do the dirty work at cleaning up our mess

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