From the CO2Science archive: Bluegrass (Poa pratensis L.) is not blue, nor is it confined to Kentucky. It’s a popular green lawn grass across North America and Europe, and may be even more popular as the amount of CO2 in the air goes up. CO2Science reports on 11 experiments from 2001 to 2018 which found that, with an additional 300 ppm CO2 in the air, the average increase in growth was 116%. Fire up those mowers, gentlemen.