VATICAN CITY (AP) — One city banned Styrofoam. Another has the highest percentage of "clean" cars in Europe. Still another has cut greenhouse gas emissions by 29 percent since 1990 — while its GDP grew 19 percent.
Dozens of environmentally friendly mayors from around the world are meeting at the Vatican Tuesday to bask in the star power of eco-Pope Francis and commit to reducing global warming and helping the urban poor deal with its effects.
It's the latest — and perhaps most important — Vatican initiative to keep the momentum alive after Francis released his landmark environment encyclical and as governments head into crucial climate negotiations in Paris in December.
Already, the Vatican has engaged Nobel science laureates, global faith leaders, the U.N. leadership, eco-friendly businesses and even the self-described "secular Jewish feminist" and environmental advocate Naomi Klein to promote Francis' message that caring for the Earth — and humanity — is an urgent moral imperative.
Now, the pope is turning to mayors, some 60 of whom signed up to attend the two-day meeting at the Vatican. Several belong to the new Carbon Neutral Cities Alliance, whose members have committed to reducing greenhouse gas emissions by at least 80 percent by 2050 or sooner.
Attending is Gov. Jerry Brown of California, which has enacted the toughest greenhouse gas emissions standards in North America, as well as the mayors of New York City, Boston, Oslo, Vancouver and Boulder, Colorado.
Also represented is San Francisco, which has banned plastic bags and Styrofoam; Stockholm, which has the highest percentage of clean vehicles in Europe; and Berlin, which cut its emissions by 29 percent in the past 25 years.
Other mayors hail from the developing world: Libreville, Gabon; Siquirres, Costa Rica and Kochi, India.
Experts have long said that cities are key to reducing global warming since urban areas account for nearly three-quarters of human emissions. Mayors are also on the front lines in responding to the effects of climate change — especially when seawater enters coastal cities' freshwater systems or when floods hit as a result of global warming-induced severe weather.
"They can't afford the luxury of a false debate over whether the problem is real," said Alden Meyer of the Union of Concerned Scientists, which has been active for decades in international climate negotiations. "They're dealing with the consequences already."
In his sweeping manifesto last month, Francis blamed global warming on an unfair, fossil-fuel-based industrial economic model that harms the poor the most. Many conservatives have rejected or dismissed the encyclical as flawed and irresponsible: Even the pope's financial czar, Cardinal George Pell, a perceived climate skeptic, has said the church has no business pronouncing on matters of science.
But the Vatican has pressed ahead to create a broad coalition to promote the message, part of Francis' belief that grass-roots movements and non-traditional players are key to changing the global system.
The conference is also addressing another of Francis' priorities: human trafficking. Organizers say climate issues and trafficking both involve the exploitation of the Earth and its people, with the poor hit the hardest.
The mayors are expected to sign a declaration addressing both issues and hear a pep talk from the pope himself.
Follow Nicole Winfield at www.twitter.com/nwinfield