Nicole Winfield?and Tom Odula

NAIROBI, Kenya: Pope Francis warned Thursday that it would be “catastrophic” for world leaders to let special interest groups get in the way of a global agreement to curb fossil fuel emissions as he brought his environmental message to the heart of Africa on the eve of crucial climate change talks in Paris.

Francis issued the pointed warning in a speech to the U.N.’s regional office here after celebrating his first public Mass on the continent. The joyous, rain-soaked ceremony before 300,000 faithful saw the Argentine pope being serenaded by ululating Swahili singers, swaying nuns, Maasai tribesmen and dancing children dressed in the colors of Kenya’s flag.

Francis took aim at those who reject the science behind global warming.

“It would be sad, and dare I say even catastrophic, were special interests to prevail over the common good and lead to manipulating information in order to protect their own plans and interests,” Francis said.

Francis, who has said global warming is “mainly” man-made, said the world was faced with a stark choice in Paris: either improve or destroy the environment. He said he hoped the talks next week would approve a “transformational” agreement to fight poverty and protect the environment by developing a new energy system.