The Rome-based Catholic Sant'Egidio Community and the Federation of Protestant Churches in Italy lobbied the Italian government to grant 1,000 humanitarian visas for particularly vulnerable refugees.

"I'm going to Mexico not as a wise man bearing things, messages, ideas or solutions to problems...But I will seek the wealth of faith that you have; I want to come in contact with that wealth of faith."

"Our big hope is that people see that caring for the climate, caring for the earth is a moral obligation," said Sister Joy Peterson. "It's not political, even though we need to influence politicians, but it's an issue so important to the future of all creation. We also want to stimulate further response to the encyclical reminding people of that message that earth is our common home."

Health officials have urged women to postpone their pregnancies for two years.

Boats arrive on Europe's shores daily, or sink on the way—like the one that capsized off Turkey's coast on Saturday, killing at least 37 people including babies and other young children. Images from the latest tragedy, including the bodies of children, failed to generate the same level of shock.

The U.N. agency took the rare step despite a lack of definitive evidence proving the mosquito-borne virus is causing a surge in babies born with brain defects and abnormally small heads in Brazil and following a 2013-14 outbreak in French Polynesia.