From the CO2Science.org archive: Canada continues to emit lots of CO2 into the air despite decades of promises and hundreds of billions spent trying to stop. While that makes many Canadian tree huggers unhappy, the mighty tree Tsuga canadensis (L.) Carr. aka eastern hemlock aka Canadian hemlock is as happy as a towering conifer can be. In 1990 and 1997 three experiments were conducted showing that an extra 300 ppm more CO2 in the air boosted hemlock seedling growth by an average of 34 percent.