There's striking new evidence that Earth's atmosphere is increasingly saturated with carbon dioxide, the major gas from fossil fuel emissions that trigger climate change. ... "This should be taken as a warning," said Ken Caldeira, an atmospheric scientist with the Carnegie Institution's department of global ecology at Stanford University. "It is time to stop building things with tailpipes and smokestacks. "It is time to stop using the sky as a waste dump for our carbon dioxide pollution. If we fail to heed this warning, our children will end up living in a world that is much hotter than any human...