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Soils, Forests, Food, Water And Climate: Time For Joined-Up Action

25/10/2016 10:08

A high level meeting in London on Wednesday October 26th will consider a question that is among the most important challenges facing humankind. It's one, however, that is paradoxically also among the least talked about: soil damage. The degradation of soils presents ramifications as profound as antibiotic resistance and terrorism, yet the on-going destruction of the Earth's fragile living skin has been barely on the international agenda.

It is estimated that since the middle of the 20th century about one third of farmed soils have been damaged. While we might have in mind deeply gullied tropical soils, deforested and wrecked by heavy rain, those of us living in countries like the UK can find plenty of examples much closer to home, including in the Fens of Cambridgeshire.

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In that part of the world many of the soils are made from peat - un-rotted plant remains that accumulated over the thousands of years in the conditions that followed the end of the last Ice Age, when sea level rise caused a vast swamp to form across that low lying part of Eastern England. These lowland peatlands turned out to be very good for farming, at least when they were dried out. During the middle of the 19th century extensive drainage works were undertaken with steam-powered pumps so as to render the land suitable for crops. Reed beds and shallow lakes were replaced with wheat fields and potatoes.

So as to measure how the land might shrink as it dried, in 1852 a metal post was pushed through one area of peat at Holme Fen. It was driven into the clay beneath the peat and its top left level with the ground. Although for the last 164 years the post stayed where it was, the soil didn't. A trip up there today reveals how the post now towers about four meters above ground level, in part because the peat has shrunk and blown away. Nearly all our food comes from soil so soil degradation is of course a major issue for future supply.

The peat soils of the Fens are among the most productive in England but as they disappear the clay beneath each year gets closer to the surface. When all the peat has gone (a near-term prospect in many Fenland areas) the kind of farming that is presently carried out there will come to an end too. That's not all, another big issue arising from soil damage is the release of climate-changing carbon dioxide gas to the atmosphere.

Peat is basically made of two things - water and organic carbon. Take away the water and the carbon is exposed to the air. When that happens, it unites with oxygen in the atmosphere and becomes carbon dioxide. This so called oxidation of the peat is actually the main reason why that post now rises so far above the desiccated Fen we see today. Across a huge area of Cambridgeshire, Norfolk and Lincolnshire the drainage of The Fens has over the years led to the peat literally turning into thin air, in the process thickening the blanket of greenhouse gases that are now warming our world. Many other areas of peat, from Scotland to Indonesia and from Russia to the Congo, are undergoing a similar fate, gradually degrading and releasing vast quantities of carbon to the atmosphere.

All soils contain some carbon in the form of organic matter and in the case of peaty soils a great deal of it. In all cases though the more of it there is the ground the less carbon there is the atmosphere. Organic matter is also from where plant nutrients are naturally replenished and is thus the source of soil fertility. Because it increases soil water retention raising the level of soil organic matter is also a very good way to build resilience against the impact of droughts. Modern industrial farming methods have progressively reduced soil organic matter (dramatically so in places like the Cambridgeshire Fens) and this on-going degradation of soil health poses a number of threats. All of this is why this week's meeting is so important.

It's been organized by The Prince of Wales' International Sustainability Unit, in collaboration with the French and British Governments, and will take place at Lancaster House, London. His Royal Highness the Prince of Wales, who has repeatedly raised concerns about the effects of the interrelated matters of soil damage, climate change, food security and deforestation, will attend too. In finding strategies that combine solutions to all these questions at once it is increasingly clear that the idea of sustainable landscapes must be at the centre of the response.

That in turn is about finding the best ways of providing food and water for people while at the same time protecting wildlife habitats, sustaining rural livelihoods, reducing greenhouse gas emissions and adapting to climate change, all in the same landscape and with improved soil health at the core. It is a complex and challenging job, but it can be done. Among the steps that can be taken include moves to increase soil organic matter through more diverse crop rotations, mixed farming systems that combine crops and livestock, the application of compost and the addition of charcoal to soils. All this can help to not only catch carbon, hold water and improve soil fertility, but also to reduce the need for the manufactured fertilizers that otherwise come with such a high greenhouse gas footprint.

At the same time it has been realized that across many landscapes positive progress can be made through the restoration of forests, whereby mosaics of farms and natural habitats can be combined to make optimal use of the land for food, water, wildlife, jobs and carbon all at once. The meeting will discuss how best to pursue that goal too, through among other routes the 'Bonn Challenge on Forest Landscape Restoration' that was adopted in 2011 and which now pursues the aspiration to restore 150 million hectares of the world's deforested and degraded lands by 2020 and 350 million hectares by 2030. About 50 countries have already made ambitious commitments under the Bonn Challenge and the meeting will discuss how these targets can be achieved.

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While the nexus of issues that converge around the health of soils have been relatively neglected in international discussions, this meeting can hopefully create some momentum toward large-scale action. This is not least because there will be some senior leaders there, including Andrea Leadsom, the U.K.'s Secretary of State for Environment, Food and Rural Affairs, Rory Stewart, British Minister of State for International Development and French Minister of Agriculture, Stéphane Le Foll. Alongside the host country leaders will be senior figures from a host of other nations, including Germany, Brazil, Argentina, Burkina Faso, Uruguay, Senegal, Ivory Coast and the USA.

It is hoped that the meeting's ideas on sustainable landscapes will be passed on through to the next round of climate change talks that will take place next month in Marrakech, Morocco. It might be that at that meeting additional momentum could be put behind a French initiative on soil health and climate change launched last year at the successful Paris climate change summit. If we are to limit the rate of global warming to below 2 degrees compared with pre-industrial times, never mind the 1.5 degree goal that the Paris meeting agreed, then action on soils and forests are vital aspects of what's needed.

If we can make progress on soils and forests then that would be a very good thing, for the simple fact is that the health of these incredibly intricate and complex systems underpin human welfare in fundamental and irreplaceable ways. The longer we neglect that reality in how we treat these natural assets, then the greater the future risks we court, for food security, water supply and climate change, never mind for the conservation of the amazing tapestry of life with which we share this small world.

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