According to the report, soil degradation (the loss of soil and decline in quality) drives climate change in two ways:
- Plant growth is compromised – with fewer, weaker plants less carbon is taken from the atmosphere through photosynthesis (this is the chemical process plants use to produce their food)
- The carbon naturally stored in the soils is released to the atmosphere as the soil itself is lost.
Peat, a kind of organic soil, is the world’s largest terrestrial carbon store. Peatlands cover just 3% of the Earth’s surface yet hold 30% of the world’s soil carbon. This is twice as much carbon as stored in all the Earth’s forests combined!
Peatlands form over thousands of years. They are the accumulation of layers and layers of slowly decomposing plants, which over time turns into an organic soil we call peat. Peat can only form in very wet conditions, which cause the plants to rot very slowly. On average, it takes about 1,000 years to form just one metre of peat. Some of the UK’s peatlands are 11 metres deep – that’s 11,000 years of soil formation!
Peatlands are a very special habitat in the UK as we generally have the wet, cool conditions to allow them to form! However, whilst they cover 2.4 million hectares of the UK, around 80% of them are in a bad condition. Yorkshire Wildlife Trust manages the Yorkshire Peat Partnership, which works across the Yorkshire Dales and North York Moors National Parks and Nidderdale Area of Outstanding Natural Beauty, where there are 70,000 hectares of the peatland habitat, blanket bog.
The UK is home to 20% of the rare habitat, blanket bog, which has formed over thousands of years and taken us just sixty years to devastate.
Most damage occurred in the 1950s, 60s and 70s, when government subsidies were paid in an attempt to drain the land to make it more productive for agriculture. Drainage channels, known as grips, were dug across huge areas of peatlands. These ‘grips’ criss-cross the blanket bog landscape today and drain much of the water that would have previously been held on the land. In these dry conditions, Sphagnum mosses (the building blocks of peat formation) and other peat-forming plants are unable to survive.
As the plants on the surface of the peatland die, the peat soil underneath is exposed. This has three major impacts:
- The carbon stored within the peat is released into the atmosphere as the soil is exposed, dries out and erodes (on a UK-scale this releases an estimated 18.5 million tonnes of carbon dioxide annually, which put into context is more carbon released by all the UK oil refineries in a year)
- The peat is washed into the drainage channels (grips) and end up in our water, creating brown water
- Peat soil around the grips erode creating wider channels, known as gullies, allowing even more water to drain from the peatland.
Gullies lead to even more erosion of the soil, as the water flows quickly off the peatland taking the soil with it.