How can the pig industry reduce its environmental impact?

The latest results from an ongoing investigation into the environmental impacts of livestock farming indicate that the problem of rising ammonia emissions is only getting worse, and at a great cost for native wildlife and human health.

The study investigated ammonia emissions at and around UK livestock farms of varying size, with a focus on the larger, commercial units. According to reports by Defra, ammonia, being the only pollutant for which emissions are rising, increased by 10 percent between 2013 and 2017 to a massive 245,000 tonnes in the UK - 90 percent of which was produced by agriculture.

Analysing the impacts of ammonia on ancient woodland in Wales, it was found that Nitrogen sensitive lichen are suffering greatly due to such high volumes of ammonia in the air. This could have dire knock-on effects beyond what is visibly being damaged. The Bureau of Investigative Journalism says that the full, coral-like lichens that are sensitive to nitrogen usually provide good habitats for spiders and other invertebrates, which in turn provides food for woodland birds. Lichens and similar organisms can also absorb half of all rainfall in forest ecosystems, preventing erosion and flooding as well as storing water that is later released in drier periods. The dying off of these lichen species will be catastrophic for British flora and fauna.

With ammonia being an air-borne molecule, it can also travel for miles on the wind and can mix with industrial and car fumes, creating a form of “particulate matter”, PM 2.5, that, according to Matt Hancock, UK health secretary, has been linked to higher death rates, respiratory problems, cardiovascular diseases, cognitive decline and low birth weights.

“PM2.5 is probably responsible for somewhere between half and three quarters of the total harm we derive as humans from air pollution,” said Alastair Lewis, a professor of atmospheric chemistry at the National Centre for Atmospheric Science, when speaking to The Bureau of Investigative Journalism. He explains that about half of PM2.5 in urban areas is associated with ammonia.

In response to the latest emission figures, the UK government has now launched a Clean Air strategy. Addressing complaints that ammonia emissions are not being recorded comprehensively, and increasing surveillance on all livestock species, the UK government promises to regulate ammonia reduction measures in farming. This said, some experts are sceptical and demand that grant schemes and environmental stewardship awards be extended to all areas in the UK, in order to provide all farmers with the means to responsibly care for the land they farm upon.

Read the the full results of the investigation here: Deadly gas: Cutting farm emissions in half could save 3,000 lives a year, and here: How ammonia is killing off the countryside.