NYC discovered that its largest buildings were far and away the largest contributors from the city of greenhouse-gas emissions. In fact, the city discovered that “5 percent of buildings contributed 36 percent of citywide greenhouse-gas emissions.”
The good news: substantial progress has been made.
The bade news: much of the progress was from low-hanging fruit such as discontinuing the use of heavy fuel oil, and progress was uneven—office buildings performed much better than apartment buildings or hotels.
Here is the article from Architectural Record.