Greenhouse gas (Ghg) emissions from agriculture shrank 21 per cent between 1990 and 2009 according to government figures released this week. A report published yesterday by Defra showed overall drops in greenhouse gas emissions; carbon dioxide dropped by 49.5 million tonnes, methane emissions fell 19 per cent and nitrous oxide emissions dropped by 23 per cent. image expired

The fall in emissions has been linked to the decline in numbers of the UK’s cattle and sheep herds, as livestock produce methane and manure stored for fertiliser gives off gasses when decomposing.

The report revealed that, "Since 1990, the numbers of cattle and sheep in the U.K. have fallen significantly and this explains the majority of the fall in recorded [methane emissions]. When manure is stored or treated as a liquid in a lagoon, pond or tank, it tends to decompose anaerobically and produce a significant quantity of [methane]."

Defra said the emissions fell due to declines in the dairy herd after the introduction of milk quotas and as a result of foot and mouth disease in 2001, while the pig and sheep herd declined in response to disease and higher feed prices.

However, although the reduced emissions initially appear to be good news for UK agriculture, which generates 37 per cent of methane emissions and 79 per cent of nitrous dioxide, Defra revealed that any reductions would be offset by increases in emissions from other countries whence importers purchase animal products.

The department clarified, "While production has fallen in the U.K., which may result in lower total emissions, in the main domestic production, in particular meat and dairy products, has been replaced with imports. Any reduction of emissions in the U.K. will have been at the expense of increases overseas."

Defra hopes information will boost understanding

Defra said it has hopes that the information relayed in the report would go some way towards raising awareness and encouraging farmers to reduce their emissions. The report said that insufficient information is available on farming practices which reduce emissions.

The department explained, "Many farmers say they are aware of climate change and agree that something needs to be done to reduce greenhouse-gas emissions, but there is a gap between this opinion and the level of farmer understanding of GHGs from agriculture and of mitigation measures they could adopt." 

After it was revealed last month that, overall, UK Ghg emissions are not falling fast enough to meet targets, having risen by 3 per cent instead of the 3 per cent drop needed to remain in line with targets, members of the farming industry asked for more support to fall in line with the government’s Greenhouse Gas Action Plan.

Defra and the NFU have both said they hope the latest figures will help boost knowledge and increase the uptake of practices for reducing greenhouse gasses. Ceris Jones, NFU climate change advisor, said she was pleased the government "Recognised the contribution that on-farm anaerobic digestion could make in reducing emissions and suggested the need for appropriate support."

The Defra report concluded "Ensuring a greater understanding of GHG emissions is likely to be an important driver for change for some farmers. A greater understanding of the issue may also lead to more innovative and cost-effective solutions for reducing agricultural GHGs."