Climate Change

GWP100 or GWP*: Meat, dairy lobby pushing for new methane metric. How this will enable greenwashing

New method takes current methane emissions as baseline to present minor reductions as negative emissions or cooling

By Shagun
Published: Tuesday 14 November 2023
Photo: iStock__

Some of the world’s big, industrialised meat and dairy companies have been promoting a new metric for measuring methane emissions, called GWP* (pronounced as GWP star), which they argue is a more accurate way to calculate emissions from the greenhouse gas (GHG). However, by adopting this new method, they can manipulate their overall GHG emissions and escape accountability by falsely claiming climate neutrality, a new report has revealed. 

The established metric under the 2015 Paris Agreement for measuring the global warming potential of a gas over a 100-year period is GWP100, which is the global warming potential evaluated over a 100-year timeline. It focuses on the absolute level of emissions. 

GWP100 measures the warming effect of a quantity of a non-carbon dioxide (CO2) GHG, emitted at a given point in time, relative to an equal amount of CO2. On the other hand, GWP* focuses on changes in emissions over decadal timescales rather than absolute levels. 

The report, titled Seeing Stars, is authored by food systems researcher Nicholas D Carter and co-author Nusa Urbancic from campaigning organisation Changing Markets Foundation. The paper argued that by taking current levels of methane emissions as their baseline, high-polluting countries and companies can use GWP* to present even minor reductions in methane as negative emissions or cooling. 

The report said:

The application of GWP* at a national or corporate level requires setting certain parameters that can radically alter how the impact of the same emissions is presented. Depending on the choice of baseline year, the same volume of methane emissions can be described as causing warming, no warming or even cooling. This has meant it can be used by major methane emitters to justify continuing business as usual, resulting in lack of action to cut methane emissions

The researchers looked at different levels of emissions reductions for Tyson, one of the world’s largest processors of chicken, beef and pork and Fonterra, the largest dairy exporting company. Using both GWP100 and GWP* metrics, they found that companies could claim climate neutrality with tiny levels of annual emissions reductions, 1.4 per cent and 1.7 per cent, respectively, by using the second method.

With a 30 per cent emissions reductions by 2030, Tyson would be responsible for roughly 58.5 million tonnes of CO2-equivalent using GWP100. Half of these emissions would be from methane. The emissions amount is similar to the annual emissions of Peru. 

However, using GWP* could enable the company to claim to be reducing around 82.6 million tonnes of CO2 equivalent from the atmosphere. 

For Fonterra, a 30 per cent reduction between 2020 and 2030 calculated with GWP* would enable the company to claim negative emissions (efforts in which CO2 is being removed from the atmosphere) of minus 19 million tonnes of CO2 equivalent. But GWP100 calculations showed it would still be responsible for roughly 21.6 million tonnes of CO2-equivalent — similar to annual emissions of Sri Lanka. 

A similar trend for New Zealand, where half of all emissions come from agriculture, mostly methane, showed that with a modest 10 per cent reduction in methane emissions, the country could report negative methane using GWP* by 2038. 

Efforts to push for GWP* 

The researchers found evidence of the big agriculture lobby pushing the GWP* methodology in New Zealand, Ireland, United States and other regions. At least 16 industry groups across the UK and New Zealand, including Beef + Lamb New Zealand and UK farming unions, have jointly urged the IPCC in 2020 to adopt GWP* for assessing warming impacts.

Internal documents from Ireland’s Department of Agriculture, Food and Marine were keen to adopt GWP* in the context of serious concerns that Ireland may “fail to achieve an ambitious 51 per cent reduction target due the agrifood sector’s volume of biogenic methane”, it further highlighted. 

Why GWP* is contentious

The ability to easily compare the contributions of different gases to climate change to assign accountability and set fair goals is crucial for global climate commitments. “The time horizon used to determine the GWP is important because it affects how much weight is given to short-term warming,” the report said. 

It claimed that the industry and trade groups were heavily lobbying for GWP* to be used in government policy, international standards and private carbon counting initiatives. But it has been criticised on a global policy level because it has the potential to reward the highest historically polluting countries or companies for their past GHG emissions by giving them credit for slight decreases from a high baseline. 

The methodology will also penalise countries with historically low levels of methane emissions for small increases.

GWP* was developed in 2016 by a team of researchers from Oxford University, led by two academics who argued it was more accurate than the current systems used to report national methane emissions at the international level. It was then introduced in 2018 at 24th Conference of Parties (COP24) to the United Nations Framework Convention on Climate Change. 

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