Pope Francis is marking a day he has dedicated to praising and protecting nature's marvels.

He will lead special prayers Tuesday evening in St. Peter's Basilica. The activity is part of his push to inspire efforts to save and safeguard the environment. He laid out what he sees as the urgent need to do so earlier this year in an encyclical, a formal document of Catholic church teaching.

Francis picked Sept. 1 because it is the same day Orthodox Christians similarly hail creation. He sees environmental protection as an issue that can bring Christians together.