Too little will not produce enough carbon dioxide for the bread to rise as well as it could. (imglutenfree.com)
Have we put enough carbon into the atmosphere that we're going to feel the repercussions of climate change for decades to come? (obamawhitehouse.archives.gov)
The issue is getting enough carbon out to get down to some cold point that stops other carbon sources, mainly from the ocean. (realclimate.org)