I'll readily admit it—my environmental concerns tend to take a short hiatus whenever it's really hot outside, such as during the four-day heat wave we just endured in the northeast. Simply put, I love air conditioning. While automakers have long since ditched ozone-depleting chemicals by switching to R-134a refrigerant, it turns out some companies are hard at work in developing next generation systems that run on—of all things—CO2, among other options.

AutoblogGreen reports that the German Automotive Association has already chosen to use CO2 as the next source for automotive air conditioning. Meanwhile, DuPont and Honeywell are proposing an alternative known as HFO 1234-yf, which is a chemical refrigerant that unfortunately has lower efficiency than current systems. The report said that several auto manufacturers are meeting at an event next week in Phoenix, Arizona to discuss this very topic—stay tuned.