Key takeaways

• Conventional carbon accounting measures impact over 100 years, lessening the focus on short-lived drivers of global warming.
• The Global Heat Reduction Initiative is offering an alternative accounting methodology that emphasizes near-term impacts.
• The science behind the methodology is broadly accepted, but adopting it requires trade-offs in what companies and countries value.

When companies complete their carbon accounts, a single metric is generally at the heart of the numbers: tons of carbon dioxide equivalent (tCO2e), a handy means of allowing multiple greenhouse gases to be included on the same balance sheet.

But is the focus on tCO2e causing policymakers and corporations to undervalue important methods for slowing global warming? That’s the claim being made by the Global Heat Reduction Initiative (GHR), backed by notable scientists and offering what it says is a more holistic form of carbon accounting. The initiative is a spin-off from SCS Global Services, a standards-setter and certifier of environmental projects.

GHR’s solution involves expanding traditional emissions accounting to include different timescales. Carbon dioxide equivalence data usually rests on estimates of the global warming potential of greenhouse gases over 100 years, relative to that of CO₂. Around two-thirds of any release of methane, for example, will have left the atmosphere after around 12 years. During that time, however, the impact on warming is up to 150 times greater than CO₂. And considered over the 100-year time frame used in conventional accounting, methane’s impact is diluted to 28 times greater than CO₂.

Existing methods exclude some pollutants altogether, including black carbon, also known as soot. Black carbon particles survive in the atmosphere for just a week or so, but by absorbing sunlight and remitting the energy as heat, the short-term warming impact of the substance can be up to 1,500 times that of CO₂. Almost 6 million tons of black carbon are emitted annually, according to the Climate and Clean Air Coalition, a project of the United Nations Environment Programme.

Holistic accounting

In the GHR version of carbon accounting, emissions are inventoried and CO2e numbers presented as normal. Alongside that data, the company also shows customers how their emissions, including black carbon, will contribute to global warming over the next five to 25 years.

That can affect how different mitigation options stack up against each other. GHR’s first customer is Napa Recycling and Waste Services in California. “I wasn’t really sure what we were getting into,” said resource manager William Kelley. The company’s GHR report, which it received earlier this month, highlighted the warming impact of the black carbon generated by the diesel fuel used by some of its machinery. The report also shone a light on the short-term impact of methane released from composting operations. Kelley said the analysis made him realize that i