He said part of the obstacle is that there is difficulty assessing what are termed "Scope 3" emissions from cities, or greenhouse gas output that is not directly in their city borders. A city buying hundreds of computers, for example, can't fully assess emissions associated with those computers in the production process, which might have taken place around the world.
City transportation, which is a huge source of emissions, is also hard to measure, he said. Short of estimating the miles traveled by all vehicles within municipal boundaries, there are gaps in the data, he said. More sampling of transportation patterns would help with lack of knowledge in that sector, he said.
"We're a little premature in thinking we can come up with a good standard now," he said.
Reprinted from Climatewire with permission from Environment & Energy Publishing, LLC. www.eenews.net, 202-628-6500