Because we are emitting carbon dioxide into the air at a rate much faster than it can be absorbed, it is building up in the atmosphere and ocean. (overshootday.org)
That makes the costs of emitting carbon dioxide and other greenhouse gases higher than has previously been estimated. (climatecentral.org)
And it's important to recognize that nuclear energy doesn't emit carbon dioxide in the atmosphere. (dotearth.blogs.nytimes.com)