Annual methane emissions have reached a new record

Cows Greenhouse Gases Climate change | Greenhouse gases | Methane Emissions

Before it is itself eaten, a cow has devoured a lot of plant resources and unconcernedly blown a considerable amount of methane into the atmosphere – so from a climate protection perspective, the meat industry is not optimal.

As a greenhouse gas, methane is much more effective than carbon dioxide – and is being, unfortunately, released at record-high levels in the last few years. In 2017, it is estimated that nearly 600 million tons of methane entered the Earth’s atmosphere, more than half of which came from – indirectly – human activity. Compared to the annual average for the years 2000 to 2006, annual emissions increased by around 50 million tones, an increase of nine percent. The figures come from two studies by a group led by Rob Jackson of Stanford University, published in the journals Earth System Science Data and Environmental Research Letters.

Over a period of 100 years, methane has a 28 times greater greenhouse effect than CO2, and over 20 years the effect is as much as 86 times stronger, the researchers say. “Methane is now responsible for 23 per cent of global warming due to greenhouse gases,” said co-author Pep Canadell of the CSIRO Oceans and Atmosphere in Canberra (Australia).

Nature hasn’t followed up yet

The good news is that researchers have not been able to observe an increase in methane emissions from the thawing of permafrost soils – a scenario that is a major fear of climate protection experts. But while methane emissions from natural sources such as wetlands and volcanoes have remained almost the same over the period studied, human activity has greatly increased emissions.

The study authors cite the promotion of fossil fuels, landfills and agriculture as the main sources of the methane pollution. Cattle farming plays a special role in this: “People joke about burping cows without realizing how big the source really is,” Jackson said as reported by Stanford University. Emissions from cattle and other ruminants are almost as large as those from the fossil fuel industry for methane”.

Three regions of the world recorded particularly strong increases: Africa/Middle East, China/South Asia and Oceania including Australia. According to computer models, the main drivers are cattle breeding and the use of fossil fuels. With an increase of 4.5 million tones per year, the US also has its share of the increase in emissions, mainly through the extraction and distribution of natural gas.

A small glimmer of hope from Europe

Europe is the only region in the world whose methane emissions fell slightly in 2017 compared to the same period (2000 to 2006). “Guidelines and better management have reduced emissions from landfills, manure and other sources in Europe,” said co-author Marielle Saunois of the Université de Versailles Saint-Quentin (France). Europeans now also eat less beef and more poultry and fish.

And countermeasures are indeed particularly effective in Euroe. Although methane is a more potent greenhouse gas than CO2, it also degrades much faster in the atmosphere. Reducing man-made methane emissions would therefore quickly have an effect, the researchers said. But it would have to be a real turnaround – the short-term reduction of greenhouse gases in the wake of the corona lockdowns will have little impact on methane emissions, according to the researchers.