Funny you should ask heaven... Heres a quote from the same speech the OP is citing:
"Since everything is interrelated, concern for the protection of nature is also incompatible with the justification of abortion," the encyclical says. "How can we genuinely teach the importance of concern for other vulnerable beings, however troublesome or inconvenient they may be, if we fail to protect a human embryo, even when its presence is uncomfortable and creates difficulties?"