I'm trying to think of a project off the top of my head. Basically, whenever you replace an activity that produces CO2 but also has other pollutants.... If you were to replace, say, a coal-fired electricity plant with a renewable energy production plant, you would probably not only reduce CO2 emissions but also significantly improve air quality. There are numerous examples. I would say that in many cases you would probably get that co-benefit, but it's a co-benefit that's targeted when you're dealing with carbon trading, not a direct benefit.
On October 25th, 2018. See this statement in context.