Signing the global methane commitment won’t stop backyard barbecues

Atmospheric methane concentrations are almost three times higher than pre-industrial levels and continue to rise. Reduced emissions would help to limit climate change.

David Littleproud, Nationals leader, claims that signing the pledge could threaten backyard barbecues. Most of Australia’s emissions of methane come from agriculture (in the form of livestock emissions), followed by coal and natural gas mining.

To meet the full methane commitment, it will be necessary to invest in the industries that emit most of this gas. This will allow these industries to address climate change better and increase their sustainability while also boosting profits.

Methane and global warming

Methane is a powerful greenhouse gas that prevents some of the Earth’s radiative heat from escaping into space. Each methane emission, whether from fossil fuels or biological sources, makes the Earth warmer.

Over 100 years, a kilogram methane will have a warming effect that is 27-29.8% greater than a kilogram of CO2. Methane, unlike carbon dioxide, which can remain in the air for decades, is quickly removed by chemical reactions. Its lifespan is about 12 years.

Recent rapid increases in atmospheric concentrations of methane, which have exceeded 100 parts per trillion in the past decade, are due to an alarming positive feedback.

As global temperatures rise, methane emissions increase from the warming of wetlands as well as more frequent and larger wildfires. Gleichzeitig increases temperatures by extending the lifetime of methane.

This 30% reduction in emissions of methane is about half the amount needed to achieve the temperature targets set by the Paris Agreement, which is to limit global warming between 1.5degC and 2degC over pre-industrial levels during this century.

What is the source of Australia’s methane emissions?

Australia’s agriculture sector is the largest source of methane, emitting around 60 million tonnes of CO2 equivalent each year. The next largest source of emissions is fugitive (mostly from leakage in coal and gas mining), with about 34 million tonnes of CO2-equivalent.

Land use change, forestry, and waste are both in the same third place with 12 million tonnes each. The emissions from energy production, transportation, and industrial processes are all small.

Methane in agriculture is mainly produced by fermentation of feed, during digestion of ruminant livestock (such as cows, sheep, and goats), and animal manure. Rice production and crop waste combustion are responsible for small amounts.

In the end, this means that emissions are lower during droughts, when there is less livestock, and they eat less, but they are higher in good years.

Since 2000 there has been an overall decline of 15% in agricultural methane emission. This is largely due to a decrease in the number of sheep and better animal and feed management.

Most of Australia’s emissions are due to the agriculture industry. Nikolas Gannon/Unsplash

Emissions from land use changes have also decreased, reflecting a steep decline in the clearing of land since 2007. Emissions from the waste sector have also reduced, thanks to improvements in waste management and collection, as well as methane capture. Over the last two decades, both sectors have seen a 30 percent reduction.

However, the amount of fugitive emissions is subject to dispute. In the past year, The International Energy Agency revised upwards national numbers for fugitive emissions based on Satellite analysis and on-ground measurements. The International Energy Agency has doubled estimates of emissions from this source.

In the revised figures, fugitive emission levels are now on par with or even higher than agriculture. Open pit mines have the highest emissions of the mines surveyed.

Australia needs to measure fugitive emissions from these mines more directly and integrate satellite data and other analyses. This will help us improve our emission assessments and target and evaluate any emission-reduction efforts.

What impact the pledge may have on these industries

Since the methane pledge includes a global target for reduction, there are unlikely to be any sanctions against specific industries that do not meet this target.

Nevertheless, it may be necessary to reduce methane emissions if certain nations include agriculture as part of any border adjustment mechanism, which places taxes on imports that are high emitters. In this context, immediate action could be strategic.

Read more: What if carbon border taxes applied to all carbon–fossil fuels, too?

Additionally, emissions reduction is aligned with good practice in most major emitting industries.

Methane emissions in livestock can result in a loss of up to 6% of feed energy. Is expected to increase animal performance by reducing these losses. Existing and emerging technologies are available to reduce such emissions.

There are several options, including improved feed quality, dietary fats and oils, feed supplements, and possibly vaccines. Existing options will struggle to achieve a 30% reduction in methane emissions while maintaining productivity levels.

Landfill emissions are captured and converted into electricity. Shutterstock

Methane from landfills can be captured to generate electricity or cleaned up and fed back into the natural gas system.

Biogas generators can be used to capture food scraps and produce fertilizer.

This practice is often ineffective and causes air pollution and a href=”https://theconversation.com/the-risk-of-preterm births rises near gas flaring, reflecting deep rooted environmental injustices in rural America-143413″>problematic health outcomes/a>. This practice, however, is ineffective and can lead to health problems and air pollution.