Global climate goals have accelerated the need for a reduction in carbon emissions, but how that number is calculated has been called into question, prompting companies to invest in more accurate methods of measurement.

Most emissions figures, including those in a recent carbon-neutral liquefied natural gas sale from Cheniere Energy to Shell, are based on estimates, rather than real-time data.

Denver-based start-up Project Canary seeks to change that with its approach of reporting emissions in real time. The company recently announced pilot projects with US energy companies NextDecade and Chesapeake Energy to monitor and measure emissions from the production of natural gas and the liquefied product.

Project Canary founder and chief executive Chris Romer says that to reduce carbon emissions, companies must have accurate data to work with in the first place.

"If you can't measure it, you can't improve it," Romer says, quoting the late management consultant and author Peter Drucker.

For Project Canary, these data points are obtained through a system of field-based methane-leak detection sensors that continuously monitor and upload air quality measurements to its Canary ESG (environmental, social and governance) platform every minute. When leaks are detected, the system alerts the field operator.

Calculating exact emissions in the complex LNG value chain can be difficult.

Beginning next year, Cheniere Energy will release the greenhouse gas emissions data associated with its LNG cargo under its "cargo emissions tags".

The tags will be calculated using Cheniere’s proprietary life cycle analysis (LCA) model, which has been built incorporating the accounting frameworks from LCAs created by the US Department of Energy’s National Energy Technology Laboratory (NETL).

Tim Skone, senior environmental engineer for NETL, says natural gas is often handled by multiple companies and may be combined with gas from various other sources after extraction.

Once the gas is integrated into a single commodity in the US, the ability to trace methane back to the originating well is highly challenged.

“Developing natural gas supplier-specific profiles requires company-specific knowledge of internal purchase contracts and collaboration across their value chain,” Skone says.

Cheniere is partnering with several gas producers and academic institutions to implement better monitoring and reporting systems that will contribute to its tag technology.

Project Canary says its Trustwell certification process, which provides independently measured data and responsibility ratings for natural gas purchases, is a step toward standardising gas emissions.

Steven Miles, a fellow at Rice University's Baker Institute, says the focus on upstream and midstream sometimes means that downstream emissions are not included on LNG cargoes.

With no federal definition of carbon neutrality, he estimates about 75% of emissions may not necessarily be counted in such cargoes.

“It means we’re still lacking transparency,” Miles says. “A uniform standard would be beneficial, but what we need first is transparency.”