GARDENERS and food growers in the UK may have released as much as 31 million tonnes of carbon dioxide (CO2) into the atmosphere since 1990 by using peat compost.

Over the next two years, peat use could release a further 1.5 million tonnes of CO2 - roughly equivalent to the annual greenhouse gas emissions of more than 214,000 UK residents - while further contributing to species and habitat decline.

The new figures have been calculated by The Wildlife Trusts, which are urging the Government to ban the sale and extraction of peat for horticulture immediately - and not wait until 2024.

What is peat?

Peat is a kind of soil that forms from plants decaying in wetlands, where very slow moving or stagnant water stops oxygen from getting to the material, slowing the rate of decomposition.

This means that peatlands can store huge amounts of carbon for thousands of years.

Peatlands are also home to a huge variety of wildlife, such as carnivorous sundew plants that thrive in the wet environment, moisture-loving insects, lizards, snakes and migratory birds.

What's the problem?

Because of the way it forms, peat is incredibly rich in nutrients and is therefore a very popular growing medium both for domestic gardeners and the horticulture industry - professional growers of fruit, vegetables and flowers.

Since 1990, professionals and amateur gardeners across the UK have used between 2 and 3.5 million cubic metres of peat every year - adding up to an estimated total of 81 million cubic metres.

When this peat is removed from the water and exposed to air, it starts oxidising. This releases the carbon as CO2, which goes into the atmosphere.

When peat is extracted, this oxidisation and CO2 release happens both at the exposed surfaces in the peatlands and to the peat which is bought by gardeners and horticulturalists and used as a compost.

Each standard cubic metre of peat may contain between 47 and 104kg of carbon and, if oxidised completely, has the potential to release 385kg of CO2.

The Wildlife Trusts have used these figures to calculate that the 81 million cubic metres of peat used in UK horticulture since 1990 will be in the process of adding between 14 and 31 million tonnes of CO2 to the atmosphere as it decomposes over its lifetime as a growing medium.

This figure does not take into account the amount of CO2 released from the degraded peatlands themselves, which will also be significant.

What are we doing about it?

The campaign to stop peat extraction took off in the 1990s but the UK and Welsh governments are only now running a public consultation on ending the use of peat in the retail sector in England and Wales by 2024.

The Wildlife Trusts believe we cannot wait this long.

As well as analysing the impacts of peat extraction in the UK, The Wildlife Trusts found that the UK ‘offshores’ most of its peatland emissions and damage to wildlife to the countries who dig peat up to sell it in the UK. Currently, emissions from these imports are not counted in the UK's greenhouse gas emissions figures.

Despite 30 years of campaigning against extraction and increased public outcry, peat continues to be sold in vast quantities for amateur and professional horticultural use, with huge consequences for nature and climate.
Industry progress towards peat-free alternatives has been slow and inconsistent, and between 2018-19 peat consumption in the UK declined by just 2.3%, before rapidly increasing by 9% as lockdown drove more people to buy compost for gardening.

On average, annual UK peat sales would fill 29,000 large shipping containers and could release up to 850,000 tonnes of CO2 .

In 2020 alone, nearly 900,000 cubic metres of peat were extracted from UK soils, with a further 1.4 million cubic metres of peat imported from Ireland and the rest of Europe. A total of just over 2.29 million cubic metres of peat were dug up to be sold in the UK market in 2020, with a small quantity also being exported to other countries.

If peat is left undisturbed – in bogs, not bags – this quantity of peat could have stored approximately 238,000 tonnes of carbon for millennia to come.

However, once peatland habitats are disturbed for extraction, stored carbon becomes CO2 and is lost to the atmosphere, contributing directly to climate change.

The peat extracted for UK horticulture in 2020 could release up to 880,000 tonnes of CO2 over its lifetime as a growing medium. 880,000 tonnes of CO2 is equivalent to driving an average passenger car 2.2 billion miles – to the moon and back more than 4,600 times.

Ailis Watt, peat officer at The Wildlife Trusts, says:
“These losses are gigantic, irrecoverable and unjustifiable. Peat and the carbon stored within it simply cannot be replenished within human lifetimes. Each time governments dither over whether to ban peat use in horticulture, we risk losing more of this habitat that has taken millennia to develop, as well as losing its huge capacity for carbon storage.
“Extracting peat is bad for our climate and for wildlife. Peatlands provide habitat for a rich diversity of plants and animals. Migrating birds feed on peatland insects, while snakes and lizards also thrive in these special places. The UK is already one of the most nature-depleted countries in the world and extracting peat destroys complex ecosystems that are vital for nature’s recovery. It has to stop.
“Investing in peatland restoration whilst allowing extraction to continue is illogical and an inefficient use of public funds.”

The Wildlife Trusts are calling for an immediate ban on the sale and extraction of peat for horticulture, and a ban on importing peat from abroad.

According to our recent analysis, waiting until 2024 to ban peat use could add more than 1.5 million tonnes of CO2 to our atmosphere while further contributing to species and habitat decline. Bringing about an end to all uses of peat is an obvious step that UK Governments can take to put nature into recovery and transform peatlands from carbon emitters into carbon sinks.

The Wildlife Trusts are urging the public to respond to the Government consultation – it is open until 18 March 2022. The public are urged to take part in The Wildlife Trusts’ e-action here.