Why GWP* Is the Wrong Tool for Tackling Methane in the Dairy Industry

As global pressure mounts to address agricultural emissions, a growing number of industry groups are promoting a new metric called GWP* (Global Warming Potential Star) as a replacement for the traditional GWP100. At first glance, GWP* sounds like a scientific advance—an improved way to compare the warming impacts of different greenhouse gases, especially methane. But behind the technical language lies a troubling reality: GWP* risks undermining real climate action in the dairy sector and beyond.

Unlike GWP100, which measures the total warming caused by emissions over a 100-year period, GWP* shifts the focus to changes in emissions compared to a baseline in the recent past. This means that if a company’s methane emissions stay the same, GWP* could make it appear as though their impact on the climate has leveled off—even though methane concentrations in the atmosphere remain dangerously high. Worse, small reductions from already high levels can be spun as “cooling the planet,” allowing companies to claim “climate neutrality” while their operations continue to drive significant warming.

This approach doesn’t just distort the numbers—it shifts the goalposts. GWP* advantages those with historically high emissions, rewarding countries and companies that have contributed most to the problem, while penalizing those with smaller footprints who are still developing. That’s not just bad accounting; it’s fundamentally unfair and inconsistent with climate justice and the Paris Agreement.

As a coalition, we urge policymakers to stick with metrics that reflect the full picture. GWP* is not a neutral upgrade—it’s a loophole that lets major polluters off the hook. To make real progress, we need honest, transparent reporting that drives actual methane reductions, not creative accounting.